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1.
Pharmacokinetic and pharmacodynamic properties in goats of the non-steroidal anti-inflammatory drug tolfenamic acid (TA), administered both alone and in combination with the fluoroquinolone marbofloxacin (MB), were established in a tissue cage model of acute inflammation. Both drugs were injected intramuscularly at a dose rate of 2 mg kg−1. After administration of TA alone and TA + MB pharmacokinetic parameters of TA (mean values) were Cmax = 1.635 and 1.125 μg ml−1, AUC = 6.451 and 3.967 μg h ml−1, t1/2K10 = 2.618 and 2.291 h, Vdarea/F = 1.390 and 1.725 L kg−1, and ClB/F = 0.386 and 0.552 L kg−1 h−1, respectively. These differences were not statistically significant. Tolfenamic acid inhibited prostaglandin (PG)E2 synthesis in vivo in inflammatory exudate by 53-86% for up to 48 h after both TA treatments. Inhibition of synthesis of serum thromboxane (Tx)B2 ex vivo ranged from 16% to 66% up to 12 h after both TA and TA + MB, with no significant differences between the two treatments.From the pharmacokinetic and eicosanoid inhibition data for TA, pharmacodynamic parameters after dosing with TA alone for serum TxB2 and exudate PGE2 expressing efficacy (Emax = 69.4 and 89.7%), potency (IC50 = 0.717 and 0.073 μg ml−1), sensitivity (N = 3.413 and 1.180) and equilibration time (t1/2Ke0 = 0.702 and 16.52 h), respectively, were determined by PK-PD modeling using an effect compartment model. In this model TA was a preferential inhibitor of COX-2 (COX-1:COX-2 IC50 ratio = 12:1). Tolfenamic acid, both alone and co-administered with MB, did not affect leucocyte numbers in exudate, transudate or blood. Compared to placebo significant attenuation of skin temperature rise over inflamed tissue cages was obtained after administration of TA and TA + MB with no significant differences between the two treatments. Marbofloxacin alone did not significantly affect serum TxB2 and exudate PGE2 concentrations or rise in skin temperature over exudate tissue cages. These data provide a basis for the rational use of TA in combination with MB in goat medicine.  相似文献   

2.
Sow lameness can result in decreased animal health and productivity, and is a significant animal welfare concern. Swine producers and veterinarians lack objective assessment tools to detect lameness. Objectives of this study were to evaluate pressure algometry (PA) and thermal sensitivity (TS) as objective assessment tools for changes in pain sensitivity associated with lameness and to assess analgesic drugs for mitigating lameness pain. Twelve mixed parity crossbred sows were anesthetized and injected with Amphotericin B in the distal interdigital space of both claws of one hind leg to induce transient lameness. Sows were randomly assigned to one of three analgesic treatment groups: (1) Sodium Salicylate (SS; 35 mg/kg per os q.12 h+0.04 ml/kg IM q.24 h sterile saline), (2) Flunixin meglumine (FM; 2.2 mg/kg IM q.24 h), or (3) Control (C; 0.04 ml/kg IM q.24 h sterile saline). All sows received each treatment over three trials with two-wk wash-out periods between trials. Forty-eight h post-induction, analgesic treatments were administered daily for four consecutive d. Pain sensitivity was assessed with PA and TS on each hind leg on d−1, d+1 and d+6 relative to induction (d0). Proc Glimmix of SAS 9.2 was used to analyze the difference between sound (S) and lame (L) legs on each trial day, with a simple effect comparison used to analyze effect of analgesia treatment on d+6. As predicted, S and L legs did not differ on d−1 (P=0.56) and less pressure was tolerated on L legs on d+1 (P<0.001) (Raw Means in kilograms of force: d−1 L 7.2±0.2; d−1 S 7.4±0.2; d+1 L 2.1±0.2; d+1 S 7.7±0.2 kgf). A simple effect comparison of d+6 revealed no differences between FM and C (p=0.90), FM and SS (p=0.17), or SS and C (p=0.07). The TS latency of S versus L legs differed on all trial days (d−1 p=0.02, d+1 p<0.0001, d+6 p<0.01) over all trials. (TS Raw means (s): d−1 L 7.3±0.6; d−1 S 9.1±0.6; d+1 L 3.3±0.2; d+1 S 6.8±0.6; d+6 L 6.0±0.6; d+6 S 8.4±0.7 s), including lame and sound days. In conclusion, these results support PA as an objective non-invasive method for measuring pain sensitivity in sows induced with transient lameness. Sodium salicylate or flunixin meglumine did not reduced pain sensitivity as measured by PA from d+1 to d+6 in this model of induced transient lameness.  相似文献   

3.
A collection of 46 avian pathogenic Escherichia coli (APEC) isolates was examined for the presence of mutators by determining the rate of mutation to rifampicin resistance. The collection included 34 E. coli isolates obtained in pure culture from chronic lesions of salpingitis and peritonitis in 34 broiler breeders, of which 12 were associated with the development of secondary septicemia. Twelve additional isolates were obtained from a clonal outbreak (ST95) of E. coli peritonitis syndrome (EPS), the lesions of which changed gradually over time into a subacute/chronic form. The hypothesis of the present study was that mutation rates would be higher for chronic infection isolates than for isolates from acute infections/exacerbations. The distribution of mutation rates followed a pattern similar to that found for other clinical isolates of E. coli, with a modal/median value of 1.47 × 10−8. Of the 46 isolates, 24% (n = 11) were weakly hypermutable (2.00 × 10−8 ≤ μ < 2.00 × 10−7), however, no strong mutators were detected (μ ≥ 2.00 × 10−7). Chronic salpingitis isolates had the highest proportion (45%, P = 0.001) of weak mutators and also, significantly higher mutation rates (P = 0.003) compared to isolates that caused septicemia (4%). In addition, mutation rates were significantly lower among ST95 isolates (P < 0.0005), and among isolates from the same clonal group as ST95 (P = 0.027), when compared to isolates from other groups. Although a clear association with the time phase of infection (as lesions of EPS became more chronic) could not be observed (ρ = 0.523, P = 0.081), a higher frequency of weak mutators among chronic infection isolates suggests that increased mutation rates play a role in adaptation of APEC to long-term persistence in an infected host environment.  相似文献   

4.
The present study assessed the pathogenic effect of isolates E9, IBCB425 and IBCB159 of the Metarhizium anisopliae fungus, JAB06, JAB07 and AM09 of Beauveria bassiana, IBCB133 and CB75 of Isaria fumosorosea (=Paecilomyces fumosoroseus) and CG189 and CG195 of Isaria farinosa (=Paecilomyces farinosus) against eggs and larvae of the horn fly Haematobia irritans. Eggs were inoculated with suspensions containing 106, 107 and 108 conidia ml−1 of the fungal isolates and observed after 48 h to determine viability. In the larvae study, eggs were allowed to hatch into fresh bovine feces that had been treated with 108, 107 or 106 conidia mg feces−1. In both studies, 5 days after initial procedures, all formed pupae were transferred to an incubator at 27 ± 0.5 °C until the emergence of the adult flies was complete. The M. anisopliae isolates did not cause the death of H. irritans eggs, but they did promote the death of larvae that hatched from treated eggs, and therefore increased the total mortality. Isolate E9 promoted 100% mortality of treated larvae at a concentration of 108 conidia ml−1. For the B. bassiana isolates, no activity was observed against insect eggs or larvae. Both I. fumosorosea isolates promoted significant mortality (p < 0.05) of eggs at every concentration of conidia. Isolate CG195 of I. farinosa increased the mortality of larvae and pupae that hatched from treated eggs and promoted significant total mortality (p < 0.05) of the insect at every concentration of conidia.  相似文献   

5.
The objective of this study was to examine the relationship between easily measured, potential physiological and physical indicators of feed efficiency including metabolic hormones, metabolites, ultrasonic muscle and fat measures with performance and efficiency traits in performance tested pedigree beef bulls (n = 302; initial bodyweight 493 (SD = 64) kg). Animals were offered a high energy concentrate ad libitum plus 1.5 kg fresh weight grass hay daily and individual feed intake was measured for 70 days. Blood samples were collected by coccygeal venipuncture at the start and end of the performance test period and analysed for plasma concentrations of IGF-I, insulin, leptin and various metabolites. Similarly, ultrasonic muscle and fat depths were measured at the start and end of the test period. Residual feed intake (RFI) was computed for each animal as the residuals from a multiple regression model regressing dry matter intake (DMI) on average daily gain (ADG) and mid-test BW0.75 (MWT). Overall ADG, DMI, feed:gain (F:G) and RFI were 1.91 (SD = 0.29), 10.10 (SD = 1.31), 5.37 (SD = 0.84) and 0.00 (SD = 0.78), respectively. Residual feed intake was strongly correlated with DMI (r = 0.67) and moderately correlated with F:G (r = 0.40). Moderate positive correlations ranging from 0.3 to 0.6 were estimated between ultrasonic measures of final fat and muscle depth and their respective gains over the test period with DMI, ADG and RFI. There was no evidence of a strong association between any of the plasma analytes measured and RFI at either sampling times. However, end of test insulin was negatively correlated (r = − 0.14) with RFI. Final IGF-I concentration was negatively associated with DMI (r = − 0.14) and F:G (r = − 0.15). End of test circulating leptin concentration was positively correlated with DMI (r = 0.14) and F:G (r = 0.15). Plasma glucose concentration at the end of test was negatively related to DMI (r = − 0.21) and F:G (r = − 0.21). A positive relationship was observed between end of test plasma urea concentration and DMI (r = 0.30). Overall, the correlation coefficient estimates between the potential blood markers and measures of intake, performance and efficiency were weak and generally not different from zero. This suggests that it is unlikely that measurement of these metabolic indicators, per se, will be useful in the early identification of feed efficient animals.  相似文献   

6.
Pituitary-dependent hyperadrenocorticism (PDH) is frequent in dogs. Little is known about its presentation in different age groups and its characteristics. Dividing the population under study (n = 107) into three age groups we observed that 11.2% were young, 51.4% adults and 37.4% aged. Using magnetic resonance, pituitary tumours were intra-sellar (IS) in 30.8% and extra-sellar (ES) in 62.6% and the pars intermedia (PI) was affected in 6.5%. ES are predominant in females and IS in males (p < 0.0001). In the adult-aged population, the ES and PI are predominant, while in the young, the IS predominate (p < 0.0001). ACTH concentration was greater in the ES vs. IS (p < 0.05). α-MSH did not present significant differences according to tumour size, showing a negative correlation (r = −0.47; p < 0.01) vs. ACTH. Differences in adenoma size according to gender and their age-related frequency of apparition could be because of different origins of the corticotrophinoma.  相似文献   

7.
The development of anthelmintic resistance has made the search for alternatives to control gastrointestinal nematodes of small ruminants imperative. Among these alternatives are several medicinal plants traditionally used as anthelmintics. This work evaluated the efficacy of Cocos nucifera fruit on sheep gastrointestinal parasites. The ethyl acetate extract obtained from the liquid of green coconut husk fiber (LGCHF) was submitted to in vitro and in vivo tests. The in vitro assay was based on egg hatching (EHT) and larval development tests (LDT) with Haemonchus contortus. The concentrations tested in the EHT were 0.31, 0.62, 1.25, 2.5 and 5 mg ml−1, while in the LDT they were 5, 10, 20, 40 and 80 mg ml−1. The in vivo assay was a controlled test. In this experiment, 18 sheep infected with gastrointestinal nematodes were divided into three groups (n = 6), with the following doses administered: G1—400 mg kg−1 LGCHF ethyl acetate extract, G2—0.2 mg kg−1 moxidectin (Cydectin®) and G3—3% DMSO. The worm burden was analyzed. The results of the in vitro and in vivo tests were submitted to ANOVA and analyzed by the Tukey and Kruskal–Wallis tests, respectively. The extract efficacy in the EHT and LDT, at the highest concentrations tested, was 100% on egg hatching and 99.77% on larval development. The parameters evaluated in the controlled test were not statistically different, showing that despite the significant results of the in vitro tests, the LGCHF ethyl acetate extract showed no activity against sheep gastrointestinal nematodes.  相似文献   

8.
The pharmacokinetics of moxifloxacin were investigated in buffalo calves following a single intravenous and intramuscular administration of moxifloxacin (5 mg kg−1 body wt.). Moxifloxacin concentrations in plasma and urine were determined by microbiological assay. Pharmacokinetic analysis of disposition data indicated that intravenous administration data were best described by a two compartment open model, whereas intramuscular administration data were best described by a one compartment open model. Following intravenous administration, the elimination half life (t1/2β), volume of distribution (Vd(area)) and total body clearance were 2.69 ± 0.14 h, 1.43 ± 0.08 L kg−1 and 371.2 ± 11.2 ml kg−1 h−1, respectively. Following intramuscular administration, the absorption half life (t1/2ka) was 0.83 ± 0.20 h. The systemic bioavailability (F) of moxifloxacin in buffalo calves was 80.0 ± 4.08%. Urinary excretion of moxifloxacin was less than 14% after 24 h of administration of drug. In vitro binding of moxifloxacin to plasma proteins of buffalo calves was 28.4 ± 3.77%. From the data of surrogate markers (AUC/MIC, Cmax/MIC), it was determined in the buffalo calves that when administered by intravenous or intramuscular route at 5 mg kg−1, moxifloxacin is likely to be effective against bacterial isolates with MIC ? 0.1 μg ml−1.  相似文献   

9.
The effects of the β-adrenergic agonists ractopamine hydrochloride (RH; 0.35, 0.70 and 1.05 mg kg− 1 of BW d− 1) and zilpaterol hydrochloride (ZH; 0.10, 0.20 and 0.30 mg kg− 1 of BW d− 1) on growth performance and carcass characteristics were determined in 84 Dorper × Katahdin lambs (12 lambs per treatment), that were randomly assigned to a complete block design during a 42-day feeding trial. Lambs were fed a corn grain-based diet (18.71% CP and 12.9 MJ/kg ME). Nutrient digestibility of diets and blood serum metabolites were also determined. There were no significant (P > 0.05) differences in growth characteristics by effect of ZH or RH administration. However, lambs final weight, total weight gain and ADG increased linearly (P < 0.05) as levels of both β-adrenergic agonist increased. RH or ZH administration did not affect feed efficiency, diet digestibility or particular blood serum metabolites of lambs. Carcass characteristics of lambs consuming ZH were significantly better (P < 0.01) than RH or control lambs; RH produced significant linear response on carcass weight, dressing percentage, longissimus muscle area, carcass conformation and quality grade, and improved quadratically (P < 0.05) fat thickness and USDA yield grade of lamb carcasses. On the other hand, increasing levels of ZH decreased linearly (P > 0.01) fat thickness and improved (P > 0.05) USDA yield grade and carcass quality grade. Both β-adrenergic agonists improved carcass characteristics; although greater improvements were obtained with ZH than RH for most carcass characteristics.  相似文献   

10.
The Wistar rat is a commonly used strain for experimental animal models. Recently it was shown that results vary between studies using Wistar rats of different suppliers. Therefore we studied whether Wistar rats obtained from Harlan Laboratories (Ha, n = 24) and Charles River (CR, n = 22) had a different outcome in an acute myocardial infarction (AMI) model. AMI was induced in both Ha and CR Wistar rats by one operator. This resulted in a significantly higher survival rate for Ha (79.2 ± 10.2%) compared with CR rats (54.2 ± 10.2%, p < 0.05). Furthermore, CR rats had lost significantly more weight after 7 days (−5.9 ± 3.1%) compared with Ha rats (−0.8 ± 1.7%; p < 0.001), indicating a worse health status of the CR rats. Paradoxically, the induced infarct was smaller in CR rats (7.3 ± 3.6% of the heart) compared with Ha rats (12.1 ± 4.7%, p < 0.05). This indicates that CR rats were less sensitive for the cardiomyocyte damage subsequent to AMI induction, but remarkably showed more clinical side effects indicating that Wistar rats from two suppliers had a different response within the same AMI model.  相似文献   

11.
The relationships of live animal muscular and skeletal scores and ultrasound measurements and carcass conformation and fat scores with carcass composition and value were determined using 74 bulls. The animals consisted of 53 late-maturing breed crosses and 21 Holstein–Friesian slaughtered at 13 to 17 months of age. They were offered concentrates ad-libitum and 1 kg of grass silage dry matter per head daily for the final 139 day finishing period. Live animal muscular and skeletal scores and ultrasonic muscle and fat depth measurements of the M. longissimus dorsi were recorded at 8 to 12 months of age and pre-slaughter. Following slaughter, carcasses were classified for conformation and fatness and the right side of each carcass was dissected into meat, fat and bone. Carcass conformation and fat scores, (scale 1 to 15) ranged from 4.7 to 14.4 and 2.7 to 11.5, respectively. Pre-slaughter muscular scores showed significant positive correlations with kill-out proportion (r = 0.82), carcass meat proportion (r = 0.72), conformation score (r = 0.94), carcass value (r = 0.72), and the proportion of high-value meat cuts in the carcass (r = 0.49), and significant negative correlations with carcass bone (r = − 0.89) and fat (r = − 0.32) proportions. The associations between pre-slaughter muscular scores and proportion of high-value cuts in meat, perinephric plus retroperitoneal fat and fat score were not significant. Corresponding correlations with muscular scores at 8 to 12 months of age were generally lower than those recorded pre-slaughter. Correlations of ultrasound muscle depth with carcass traits showed similar trends but lower values to those obtained using the muscular scoring procedure. Ultrasound fat depth pre-slaughter was positively correlated with carcass fat proportion (r = 0.56) and fat score (r = 0.54), and negatively correlated with carcass meat proportion, proportion of high-value cuts and carcass value. Correlations with other carcass traits were not significant. Correlations of live animal skeletal scores with carcass traits were generally non-significant. A one unit (scale 1–15) increase in carcass conformation score was associated with significant increases in kill-out proportion, meat yield and carcass value of 11.9 g/kg, 11.9 g/kg and 5.8 cent/kg, respectively. Corresponding effects for a one unit change in fat score were − 2.9 g/kg, − 11.1 g/kg and − 4.9 c/kg. In conclusion, live animal muscular scores and ultrasound measurements and carcass conformation and fat scores were shown to be useful predictors of carcass composition and value.  相似文献   

12.
The effect of probiotic, Bacillus coagulans NJ0516, on growth performance and digestive enzyme activity of Arbor Acres (AA) broilers was investigated. Strains NJ0516 were added to commercial basal diets as probiotic at three final concentrations: T-1, 1 × 106 cfu g−1; T-2, 2 × 106 cfu g−1 and T-3, 4 × 106 cfu g−1, respectively. Twelve groups, of 30 broilers, with three replicates for each treatment group (T-1, T-2 and T-3) and the control group treated without probiotic were used. After 49 days, broilers receiving the diets supplemented with probiotic showed significantly better growth performances including final weight and daily weight gain (DWG) than those fed the basal diet (control). As for feed conversion ratio (FCR), T-2 and T-3 showed lower value (P < 0.05) than the control. However, there was no significant different in final weight, DWG and FCR between T-1, T-2 and T-3 and the survival rate was not affected (P > 0.05) by the dietary treatments. The higher protease activities were observed in T-2 and T-3 (P < 0.05) compared with the control and T-1. However, there was not significantly different (P > 0.05) between T-2 and T-3 in protease activity. Amylase activity in T-1, T-2 and T-3 was remarkably higher (P < 0.05) than that in the control. Significantly higher amylase activity was observed in T-2 compared with that of T-1. There was no remarkable difference (P > 0.05) in amylase activity of T-2 compared with that of T-3, even though there was a tendency for increased activity. As for lipase activity of duodenum in broilers, assays showed no difference in all treatment groups. It showed that probiotic, B. coagulans NJ0516 administration in feed with a certain concentration displayed a growth promoting effect and increased the protease and amylase activities.  相似文献   

13.
The purpose of this study was to evaluate arterial blood gases in dogs that were given hydromorphone or extended release liposome-encapsulated hydromorphone (LEH). Dogs were randomly administered LEH, n = 6, (2.0 mg kg−1), hydromorphone, n = 6, (0.2 mg kg−1) or a placebo of blank liposomes, n = 3, subcutaneously on separate occasions. Arterial blood samples were drawn at serial time points over a 6-h time period for blood gas analysis. There was no change from baseline values in PaCO2, PaO2, (HCO3-), pH, and SBEc in the dogs that received the placebo. Administration of hydromorphone resulted in significant increases in PaCO2 (maximum (mean + SD] 44.4 + 1.1 mm of Hg) and significant decreases in PaO2 (minimum (mean + SD) 82.4 + 4.7 mm of Hg) and pH (minimum (mean + SD) 7.31 + 0.01) compared with baseline. Administration of LEH resulted in significant increases in PaCO2 (maximum (mean + SD) 44.6 + 0.9 mm of Hg) and significant decreases in PaO2 (minimum (mean + SD) 84.8 + 2.6 mm of Hg) and pH (minimum (mean + SD) 7.34 + 0.02) compared with baseline. There was no significant difference between these two groups at any time point. The changes observed in PaCO2, PaO2, and pH, however, were within clinically acceptable limits for healthy dogs. LEH was determined to cause moderate changes in arterial blood gas values similar to those caused by hydromorphone.  相似文献   

14.
N and P surpluses per hectare at farm level were determined on 63 private pilot farms with data from 2 to 7 years between 1997 and 2003 (a total of 245 observations). Farms were classified in the following four farm types: Conventional mixed dairy, organic mixed dairy, conventional pig farms (indoor) and conventional pig farms with outdoor sows. Import of nutrients with concentrate and fertilizer was the major input to all conventional farm types. On the organic dairy farms major input was N fixation, but also import of nutrients with concentrate and manure were important inputs. Output from the dairy farms was dominated by nutrients in milk. On pig farms nutrients in meat dominated the output, but also export of nutrients with cash crops and manure were important outputs. Farm type, year and farm within farm type significantly affected both N and P surpluses per hectare. Farm type was the major source of variation in both N and P surpluses. In the period investigated N surplus decreased by 6.5 kg N ha− 1 yr− 1 and P surplus decreased by 0.7 kg P ha− 1 yr− 1. The N and P surpluses observed on the conventional dairy farms significantly exceeded surpluses observed on the organic dairy farms. At equal number of livestock units (LU) per hectare (1.28 LU ha− 1) the difference was 43 kg N ha− 1 and 6 kg P ha− 1. At equal rates of N or P in manure to fields (147 kg N ha− 1, 29 kg P ha− 1, respectively) the difference was 45 kg N ha− 1 and 4 kg P ha− 1. Conventional dairy farms and pig farms with sows indoors had equal N and P surpluses at equal rates of N or P in manure to fields. Corrected to the average year (1999.5) the estimated average N and P surpluses showed highest levels on pig farms with outdoor sows (251 kg N ha− 1, 42 kg P ha− 1) and lowest levels on organic dairy farms (113 kg N ha− 1, 7 kg P ha− 1). Surpluses on the conventional dairy farms were 175 kg N ha− 1 and 16 kg P ha− 1 and on the indoor pig farms they were 123 kg N ha− 1 and 13 kg P ha− 1. The N and P surpluses observed on Danish conventional mixed dairy farms were comparable with intensive dairy farming systems in other European countries.  相似文献   

15.
Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n = 1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010–2012. Cloacal and tracheal swabs and serum samples from domestic (n = 1242) and wild birds (n = 807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n = 306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n = 51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F = 15.7, p < 0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F = 29.5, p < 0.0001).  相似文献   

16.
Present study examined the effect of VGCC L-type blocker - nifedipine given i.c.v. (0.25, 0.5, 1 and/or 2 mg in toto) on the development of nociceptive behavior, clinical symptoms, plasma catecholamin concentration and reticulo-rumen motility following 5 min lasting mechanical duodenal distension (DD) in sheep. After 24 h of fasting, all animals received i.m. ketamine analgesia (20 mg kg−1 B.W) and anesthetized with pentobarbital (20 mg kg−1 B.W., i.v. infusion) The permanent stainless steel cannula 29 mm in length and 2 mm in diameter was inserted into the lateral cerebral ventricle (controlled by cerebro-spinal efflux) 10 mm above the bregma and 5 mm laterally from the midline sutures using stereotaxic method.Under the same general anesthesia/analgesia a T-shaped silicon cannula (inside diameter of 21 mm), was inserted into the duodenum (12 cm from pylorus). Second identical cannule was inserted into the dorsal sac of the rumen, a previously described. After surgery each animal was kept in individual boxes for 10 days prior to experiment and was treated i.m. with benzyl procaine penicillin 30,000 I.U kg−1 B.W.) + dihydrostreptomycine sulfate (10 g kg−1 B.W.) + prednisolone acetate (1.2 mg kg−1 B.W.) combination and i.m. ketamine (20 mg kg−1 B.W.) every day by seven consecutive days.Experimental DD was conducted by insertion and then distension of rubber balloon (containing 40 ml of warm water) inserted into sheep duodenum. Duodenal distension produced a significant increase in behavioral pain manifestations, tachycardia, hyperventilation, inhibition of reticulo-ruminal contractions rate (from 87.2 to 38.0% during 15-20 min), an increase of plasma catecholamine concentration (over 6.4-fold increase of epinephrine during 2 h following DD, 2-times norepinephrine and 84% increase of dopamine). Nifedipine infusion administered 10 min prior to DD decreased intensity of visceral pain manifestations such as: behavioral changes, hyperventilation, reticulo-rumen motility and efficiently prevent appearance of catecholamine release. These data demonstrated that the development and persistence of duodenal hyperalgesia depends on the activation of Ca2+ ion flux leading to neurotransmitters release and modulation of membrane excitability. It seems that nifedipine given i.c.v. 10 min prior to DD (as a source of visceral pain), inhibited specific receptors 1 subunits of VGCCs in target tissues, prevented depolarization of cell membranes and release of neurotransmitters responsible for pain sensitivity in sheep. The observed antinociceptive action of VGCCs type L blockers suggest that these channels play a crucial role in the modulation of acute visceral hyperalgesia in sheep.  相似文献   

17.
The secretion of prolactin (PRL) is stimulated by thyrotropin-releasing hormone (TRH), and inhibited by dopamine (DA). However, we have recently demonstrated that salsolinol (SAL), a DA-derived endogenous compound, is able to stimulate the release of PRL in ruminants. The aims of the present study were to compare the characteristics of the PRL-releasing response to SAL and TRH, and examine the relation between the effects that SAL and DA exert on the secretion of PRL in ruminants in vivo and in vitro. Three consecutive intravenous (i.v.) injections of SAL (5 mg/kg body weight (b.w.): 19.2 μmol/kg b.w.) or TRH (1 μg/kg b.w.: 2.8 nmol/kg b.w.) at 2-h intervals increased plasma PRL levels after each injection in goats (P < 0.05); however, the responses to SAL were different from those to TRH. There were no significant differences in each peak value between the groups. The rate of decrease in PRL levels following the peak was attenuated in SAL-treated compare to TRH-treated animals (P < 0.05). PRL-releasing responses to SAL were similar to those to sulpiride (a DA receptor antagonist, 0.1 mg/kg b.w.: 293.3 nmol/kg b.w.). In cultured bovine anterior pituitary (AP) cells, TRH (10−8 M) significantly increased the release of PRL following both 15- and 30-min incubation periods (P < 0.05), but SAL (10−6 M) did not increase the release during the same periods. DA (10−6 M) completely blocked the TRH-induced release of PRL for a 2-h incubation period in the AP cells (P < 0.05). Sulpiride (10−6 M) reversed this inhibitory effect but SAL (10−6 M) did not have any influence on the action of DA. These results show that the mechanism(s) by which SAL releases PRL is different from the mechanism of action of TRH. Furthermore, they also show that the secretion of PRL is under the inhibitory control of DA, and SAL does not antagonize the DA receptor's action.  相似文献   

18.
Thirty two Merino lambs (15 weeks old) fed barley straw and fish oil enriched concentrate were used to assess the effect of vitamin E (6 g kg−1 DM) and naringin (1.5-3 g kg−1 DM) on plasma lipid peroxidation (TBARS), total antioxidant status (TAS), immune response, plasma cholesterol, and triglycerides. After 21 days feeding the experimental diets, lambs were subjected to a 4 h transportation stress period and then held 4 more hours without feed. TBARS values before stress were lower for animals consuming vitamine E and naringin when compared to control lambs (P < 0.05). However, after stress all groups presented similar levels of TBARS. TAS decreased (P < 0.05) in all groups in response to stress with values recovering (P < 0.05) to pre-stress values following 4 h of rest. A rise (P < 0.05) in serum concentrations of triacylglycerol following 21 d of fish oil supplementation was dampened in lambs consuming vitamin E or naringin. Both pre-stress TBARS and triacylglycerol-reducing effects of naringin added to fish oil enriched concentrate for fattening lambs are reported.  相似文献   

19.
PK-PD integration and modeling of marbofloxacin in sheep   总被引：1，自引：0，他引：1  
The fluoroquinolone antimicrobial drug, marbofloxacin, was administered intravenously (IV) and intramuscularly (IM) to sheep at a dose rate of 2 mg kg−1 in a 2-period cross-over study. Using a tissue cage model of inflammation, the pharmacokinetic properties of marbofloxacin were established for serum, inflamed tissue cage fluid (exudate) and non-inflamed tissue cage fluid (transudate). For serum, after IV dosing, mean values for pharmacokinetic parameters were: clearance 0.48 L kg−1 h−1; elimination half-life 3.96 h and volumes of distribution 2.77 and 1.96 L kg−1, respectively, for Vdarea and Vss. After IM dosing mean values for pharmacokinetic variables were: absorption half-time 0.112 h, time of maximum concentration 0.57 h, terminal half-life (T½el) 3.65 h and bioavailability 106%. For exudate, mean T½el values were 12.38 and 13.25 h, respectively, after IV and IM dosing and for transudate means were 13.39 h (IV) and 12.55 h (IM).The in vitro minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) and ex vivo time-kill curves for marbofloxacin in serum, exudate and transudate were established against a pathogenic strain of Mannheimia haemolytica. Integration of in vivo pharmacokinetic data with MIC determined in vitro provided mean values of area under curve (AUC)/MIC ratio for serum, exudate and transudate of 120.2, 156.0 and 156.6 h after IV dosing and 135.5, 165.3 and 146.2 h after IM dosing, respectively. After IM administration maximum concentration (Cmax)/MIC ratios were 21.1, 6.76 and 5.91, respectively, for serum, exudate and transudate. The ex vivo growth inhibition data after IM administration were fitted to the sigmoid Emax (Hill) equation to provide values for serum of AUC24 h/MIC producing, bactericidal activity (22.51 h) and virtual eradication of bacteria (35.31 h). It is proposed that these findings might be used with MIC50 or MIC90 data to provide a rational approach to the design of dosage schedules which optimise efficacy in respect of bacteriological as well as clinical cures.  相似文献   

20.
Disease caused by Brucella spp. represents the most common bacterial zoonotic infection worldwide. The distribution and public health impact of these infections in Nepal's mountain regions are poorly characterized. This cross sectional study assesses the burden of brucellosis on transhumant pastoralists and their yak in and around Shey Phoksundo National Park, Nepal. Objectives were to: (1) estimate individual animal prevalence of Brucella-seropositive yak, (2) identify herd- and individual-level risk factors associated with Brucella seropositivity in individual yak, and (3) identify herd-level risk factors associated with reported human brucellosis-like symptoms in a household. A case of household symptoms was defined as the reported occurrence within the previous year of at least one of three acute symptoms (chills, fever, night chills) and one of two chronic symptoms (joint pain, swollen joint(s)) in one or both of two individuals interviewed in a household. Two-hundred-ninety-seven yak from 61 herds were sampled, and 61 household questionnaires were completed. Estimated true prevalence was 0.22 (95% CI: 0.17; 0.28). Poisson regression with generalized estimating equations was used to account for repeated measures within a cluster (herd). Yak in herds reporting abortion occurrence within the previous year were 2.3 times more likely to be seropositive than those in herds not reporting abortion (95% CI: 1.2; 4.2, p = 0.01). For every 10 animal increase in herd number, individual animal seropositivity risk increased by 30% (95% CI: 10%; 50%, p = 0.001). Male yak were 0.7 times as likely to be seropositive as female yak (95% CI: 0.5; 0.9, p = 0.01). Three to five year old yak were 2 times more likely to be seropositive than yak <3 years old (95% CI: 1.3; 3.2, p = 0.003), and yak >5 years old were 4.9 times more likely to be seropositive than yak <3 years old (95% CI: 2.9; 8.1, p < 0.001). Risk of reported brucellosis-like symptoms at the household level was 2 (95% CI: 1.1; 3.5, p = 0.02) times greater for households with herds with >1 reactor, and was 3.6 (95% CI: 1.4; 9.2, p = 0.008) times greater for households reporting the practice of raw milk consumption. These results indicate that yak seropositivity for Brucella spp. is widespread in the region, and is associated with reported human disease. This epidemiologic understanding is essential to the identification of public health opportunities at the interface of Himalayan livestock populations and the transhumant pastoralists that depend on them.  相似文献   

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