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1.
Ureaplasma species were isolated from semen samples collected sequentially from one Awassi and three Assaf breeding rams. Each ram was injected subcutaneously with an aqueous solution of lincomycin and spectinomycin for five consecutive days at a dose equivalent to 4·5 mg kg−1 lincomycin and 9·0 mg kg−1 spectinomycin daily. Serum and semen samples were collected at intervals during the treatment and assayed for lincomycin. No Ureaplasma species were isolated from semen samples collected during the course of the treatment and at intervals for 17 days after the last treatment. The concentration of lincomycin in semen ranged from 0·51 μg ml−1 four hours after treatment to 0·08 μg ml−1 24 hours after treatment, and these levels were three to nine times higher than the corresponding serum concentrations.  相似文献   

2.
The rate of reversal of neuromuscular block was compared in 36 sheep receiving either edrophonium (500 μg kg−1) and atropine (80 μg kg−1), neostigmine (50 μg kg−1) and atropine (80 μg kg−1) or saline (10 ml), using the train of four count (TO4C) recorded at n. facialis - m. levator nasolabialis. Neuromuscular block was produced with mivacurium (200 μg kg−1) followed later by a single incremental dose of 70 μg kg−1. Antagonists or saline were given when spontaneous recovery from the incremental dose (T04C = 1) = 1 begun. The T04C increased from 1 to 4 in all animals, in all treatment groups within 10 minutes of reversal. The T04C was 4 in all animals five minutes after edrophonium, and seven minutes after neostigmine; differences were not statistically significant. The T04C was significantly higher with edrophonium two and three minutes after antagonism compared with saline. The data show that spontaneous recovery from mivacurium is rapid in sheep, although reversal is accelerated by anticholinesterase drugs.  相似文献   

3.
The effect of dietary chloride content (0·2, 0·4 and 1·3 per cent chloride on a dry matter basis) on the disposition of a single oral dose of bromide (14 mg kg−1 was evaluated in normal beagles. Increasing the dietary chloride content from 0·2 to 1·3 per cent resulted in a significant decrease in the mean apparent elimination half-life from 69 ± 22 days to 24 ± 7 days. The mean area under the concentration curve ( ) for dogs fed 1·3 per cent chloride was significantly smaller than the for dogs fed 0·2 per cent chloride. Dietary chloride had no effect on the maximum serum concentrations (Cmax) or on the time (Tmax) to reach the maximum concentrations. The steady-state serum bromide concentrations predicted from the single dose data for daily doses of 14 mg kg−1 of bromide were significantly lower in dogs fed 1·3 per cent chloride (310 ± 150 mg litre−1) than in dogs fed 0·2 per cent chloride (1950 ± 1140 mg litre−1). The predicted mean daily doses of bromide necessary to maintain serum levels within the therapeutic range for dogs fed 1·3 per cent chloride (43 ± 13 mg kg−1) were almost twice as high as the dose estimated for dogs fed 0·4 per cent chloride (22 ± 3 mg kg−1) and nearly three times as high as the dose estimated for dogs fed 0·2 per cent chloride (15 ± 4 mg kg−l). These differences were statistically significant (P=0·002).  相似文献   

4.
These studies were undertaken to examine the systemic and renal effects of the pharmacological inhibition of endothelium-derived nitric oxide (EDNO) in cats. In six healthy cats, the intravenous infusion of nitro-L-arginine at a dose of 100 μg kg−1 bodyweight min−1 resulted in a marked increase (P<0·001) in mean arterial pressure from the control value of 116·7 ± 4·6 mmHg to 154·2 ± 6·8 mmHg and an increase (P<0·05) in renal vascular resistance from the control value of 3·69 ± 0·33 mmHg min ml−1 to 6·83 ± 1·15 mmHg min ml−1. The increase in renal vascular resistance was generalised, with comparable increments in preglomerular and postglomerular vascular resistance. Mean values for glomerular capillary pressure (61·1 ± 61·9 vs 1·9 ± 1·6 mmHg), calculated from the sum of arterial colloid osmotic pressure plus proximal tubule stop-flow pressure, did not change in response to the infusion of nitro-L-arginine. However, there was a marked reduction in renal blood flow (29·4 ± 3·1 to 16·9 ± 2·3 ml min−1, P<0·01) and glomerular filtration rate (5·22 ± 0·57 to 3·52 ± 0·45 ml min−1, P<0·01). These results provide evidence that EDNO plays an important role in the basal regulation of systemic arterial blood pressure and renal haemodynamics in cats.  相似文献   

5.
The concentration of ivermectin in the plasma of reindeer was measured after it was administered either topically as a pour-on preparation at 500 μg kg−1 bodyweight at different seasons to animals of different ages, or after subcutaneous and oral doses of 200 μg kg−1 bodyweight. The plasma concentrations of ivermectin were highest and least variable after it was administered subcutaneously.  相似文献   

6.
In an open, controlled, multi-centre clinical field trial, seven ‘naturally occurring’ outbreaks of acutefebrile (rectal temperature ≥ 39·5°C) respiratory disease in housed calves were treated with a single antimicrobial agent, and either the non-steroidal anti-inflammatory drug (NSAID) carprofen (n=95) or flunixin meghunine (n=92) on an alternate basis. Carprofen was administered as a single subcutaneous injection at a mean dosage of 1·4 mg kg−1 (range 1·2 to 1·9 mg kg−1) body weight on the first day and flunixin meglumine by intravenous injection at a mean dosage of 2·0 mg kg−1 (range 1·2 to 2·6 mg kg−1) body weight on the first 3 consecutive days. All calves were examined clinically immediately prior to initial treatment and on three occasions up to 1 week after the end of treatment. There were no statistically significant differences between NSAID groups in reduction of clinical parameters between examinations, or in overall efficacy. This trial demonstrated that a single dose of carprofen was equally effective as three daily closes of flunixin meglumine as adjunctive therapy to antimicrobial treatment in acute respiratory disease in calves.  相似文献   

7.
The study investigated rumen dry matter (DM) degradability characteristics in a completely randomized design and the effects of milk, sweet potato foliage (SPF) from three cultivars (A = TIS-87/0087; B = TIS-8164; C = TIS-2532.OP.1.13), dried brewers' grains (DBG) and cottonseed meal (CSM) as supplements to Panicum maximum (Panicum) for pre-weaned calves in randomized complete block designs. Diet 1 = milk + SPF-A foliage + Panicum, Diet 2 = milk + SPF-B foliage + Panicum, Diet 3 = milk + SPF-C foliage + Panicum, and Diet 4 = milk + DBG & CSM + Panicum (as control). Dry matter (130 ± 0.4 to 864 ± 3.9 g kg− 1), ash (54 ± 4.2 to 173 ± 2.8 g kg− 1 DM), OM (827 ± 4.2 to 946 ± 5.7 g kg− 1 DM), N (7.4 ± 0.6 to 38.6 ± 1.4 g kg− 1 DM), and NDF (439 ± 1.4 to 774 ± 8.5 g kg− 1 DM) contents were highly significant (P < 0.01). In Trial I, 16 pre-weaned calves were used over 70 d with milk intake (34.8 ± 4.4 ml kg W− 0.75 d− 1), Panicum DMI (22.3 ± 2.77 g kg W− 0.75 d− 1), total DMI (35.7 ± 2.83 g kg W− 0.75 d− 1), and LWG (198 ± 44.6 g d− 1) not significantly different (P > 0.05). Supplement DMI varied (P < 0.05) from 11.6 g kg W− 0.75 d− 1 in Diet 3 to 16.6 g kg W− 0.75 d− 1 in Diet 4. In Trial II, 16 pre-weaned local and crossbred calves were involved over 77 d with initial age of calves, Panicum intake, metabolic DMI, and LWG similar (P > 0.05) among crosses. Birthweight varied (P < 0.05) from 17.3 kg for N'Dama × Jersey crosses to 21.2 kg for White Fulani × Brown Swiss crosses. Supplement and total DMI ranged (P < 0.05) from 172 to 483 g d− 1 for N'Dama × Jersey crosses to 233 and 674 g d− 1 for non-inseminate or purebred calves, respectively. The LWG in the White Fulani × Brown Swiss and the N'Dama × Jersey calves were respectively 30% and 24% better, though not significantly, than purebred calves. In Trial III, rumen DM degradability characteristics of feeds in three N'Dama steers showed no significant differences (P > 0.05) in slowly degradable fraction (b) and rate of degradation of b (c). Soluble fraction (a), 48-h degradation, potential degradability (PD) and effective degradability (ED) varied significantly (P < 0.05) and were lowest in Panicum, but similar for foliage among the three sweet potato cultivars. Panicum fodder showed improvements in degradation characteristics with supplementation.  相似文献   

8.
Medetomidine was administered intravenously to six sheep at 5, 10 and 20 μg kg−1 and to one horse and four ponies at 5 and 10 μg kg−1. In both species medetomidine resulted in significant decreases in heart rate and cardiac output and, initially, in an increase in arterial blood pressure. In the ponies this increase in blood pressure was followed by a significant and prolonged decrease, but in the sheep the secondary decrease in blood pressure was not statistically significant. In the sheep, the three doses of medetomidine resulted in profound and significant decreases in arterial oxygen tensions, which were significantly dose related, but in the ponies the arterial blood oxygen tensions were not significantly decreased. In both species medetomidine caused a small but significant increase in arterial blood carbon dioxide tensions.  相似文献   

9.
The influence of training on blood lactate concentrations during treadmill exercise and a 40-minute inactive recovery period was examined in seven trained and seven detrained thorough-bred horses. Lactate concentrations were measured in venous blood collected at the end of each exercise state, and at intervals for 40 minutes afterwards. Measurements were made of maximum oxygen uptake (V̇O2max, ml kg−1 min−1), VLA4 (velocity at which blood lactate concentration was 4 mmol litre−1); LA8 (lactate concentration [mmol litre−1] during exercise at 8 m sec−1), peak lactate (highest lactate concentration after exercise), LA40 (lactate concentration 40 minutes after exercise), the time of peak lactate concentration (minutes after exercise) and the rate of disappearance of blood lactate (Rtd). The trained horses had a significantly lower LA8 (2·1 ± 0·1 vs 6·5 ± 1 mmol litre−1, P<0·01), higher VLA4 (9·8 ± 0·2 vs 5·8 ± 0·6 m sec−1, P<0·01) and higher V̇02max (156·3 ± 3·8 vs 107·1 ± 3·9 ml kg−1 min−1, P<0·001). The value of Rtd and the time of peak lactate concentration were not significantly different.  相似文献   

10.
Five days after the induction of acute systemic inflammation in greyhounds by intramuscular and subcutaneous injections of Freund's adjuvant, the hepatic concentrations of cytochromes P-450 and b5, the activities of the hepatic microsomal enzymes aniline p-hydroxylase and aminopyrine n-demethylase and the disposition and urinary excretion of phenylbutazone were determined. The mean plasma concentrations of phenylbutazone after intravenous administration were described by the bi-exponential equations: Cp = 144·2e−34·6t + 171·5e−0·104t for five normal greyhounds and Cp = 113·6e−16·13t + 163·1e−0·108t for five febrile greyhounds. The elimination half-lives, total body clearances and apparent volumes of distribution were 6·7 hours, 18·4 ml kg−1 hour−1 and 0·18 litre kg−1, for the normal greyhounds, and 6·4 hours, 19·5 ml kg−1 hour−1 and 0·18 litre kg−1, for the febrile greyhounds. There were no significant differences between the pharmacokinetic parameters describing the distribution and elimination of phenylbutazone, or between the quantities of phenylbutazone, oxyphenbutazone and hydroxyphenylbutazone excreted in the urine. In the febrile greyhounds, there were significant decreases in the hepatic microsomal concentrations of cytochromes P-450 and b5 and in the activities of aniline p-hydroxylase and aminopyrine n-demethylase.  相似文献   

11.
Six veal calves were medicated with clenbuterol at 20 μg kg bodyweight−1 day−1 for 42 days before they were slaughtered, to evaluate the lesions and residues in target organs. Compared with six unmedicated calves the most noticeable changes were tracheal dilatation, decreased uterine weight, slight mucous hypersecretion in the uterus and vagina and depletion of liver glycogen. The highest concentrations of clenbuterol (62 to 128 ng/g−1) were recorded in the choroid/retina, and the aqueous humour had the lowest concentration (0·5 to 2·4 ng ml−1). The residue concentrations were higher than the maximum residue level set for clenbuterol (0·5 ng g−1)  相似文献   

12.
Fluconazole (100 mg) was administered to six adult cats as an intravenous infusion over 30 minutes, and the same cats received 100 mg of the drug orally 16 weeks later. The cats were bled repeatedly through an indwelling jugular catheter, the plasma fluconazole concentrations were assayed by high performance liquid chromatography, and the concentration-time data were subjected to a non-compartmental pharmacokinetic analysis. The mean (SD) intravenous half-life (13·8 [2·6] hours) was similar to that observed after oral dosing (12·4 [3·0] hours). The plasma clearances (intravenous 0·9 [0·1], oral 0·9 [0·2] ml min−1 kg−1) and the volumes of distribution at steady state (intravenous 1·1 [0·1], oral 1·0 [0·1] litre kg−1) were also similar after the two routes of dosing. The peak plasma concentration was reached 2·6 hours after oral dosing and the drug was completely bioavailable (1·09 [0·05]). On the basis of this single dose study, the administration of 50 mg fluconazole every eight hours to a 4 kg cat should produce average steady state plasma fluconazole concentrations of approximately 33 mg litre−1.  相似文献   

13.
The single-dose disposition kinetics of marbofloxacin (MBX) were determined in clinically healthy loggerhead sea turtles (n = 5) after oral (PO) administration of 2 mg kg−1 bodyweight. Marbofloxacin plasma concentrations were determined by DAD–HPLC (LOD/LOQ 0.015/0.05 μg ml−1). Data were subjected to non-compartmental analysis. Following PO administration, marbofloxacin achieved maximum plasma concentrations of 11.66 ± 2.53 mg L−1 at 15.00 ± 3.00 h. The absence of general adverse reactions in the turtles of the study, and the favourable pharmacokinetic properties (long half-life and high maximum plasma concentration) of MBX administered PO at the single-dose of 2 mg kg−1 suggest the possibility of its safe and effective clinical use in loggerhead sea turtles.  相似文献   

14.
The activities of danofloxacin, a novel fluoroquinolone, and two other antimicrobials were determined in vitro against field isolates of seven Mycoplasma species of veterinary importance isolated from cattle, swine and poultry in five European countries. The minimum inhibitory concentrations (MIC) of danofloxacin, tylosin and oxytetracycline were determined against a total of 68 isolates. Danofloxacin showed excellent activity against isolates of all Mycoplasma species (range 0·008 to 0·5 μg ml−1), but in some isolates there was evidence of reduced sensitivity to tylosin (range 0·008 to 2·0 μg ml−1) and oxytetracycline (range 0·008 to over 16·0 μg ml−1). Danofloxacin was more active than other antimicrobials against, M hyopneumoniae, M dispar and M bovigenitalium, and showed activity similar to that of tylosin against M bovis and M gallisepticum. Tylosin was the most active against M synoviae and M hyosynoviae. Generally, oxytetracycline showed the poorest activity, but was superior to tylosin against M bovigenitalium. A second (final) MIC reading was taken for all isolates 14 or 21 days after the initial reading, and MIC values rose during that time. However, the increase seen in danofloxacin values (typically one to two dilutions) was less than that seen for tylosin and oxytetracycline. It is concluded that danofloxacin is highly active in vitro against all of the Mycoplasma species tested, and thus shows great potential for the treatment of respiratory and other infections caused by Mycoplasma species in cattle, pigs and poultry.  相似文献   

15.
High muscle camosine and anserine contents contribute significantly to intra-cellular physico-chemical buffering. Our aim was to measure carnosine, anserine and taurine contents directly in individual type I, HA and IIB fibres from the middle gluteus muscle of the camel. Mean carnosine contents in type I, IIA and IIB were 24·6 ±9·2, 39·4 ±11·4 and 42·8 ±18·8 mmol kg−1 dry weight (dw), respectively. Mean anserine contents in type I, HA and IIB fibres were 30·0 ±8·4, 37·3 ±10·1 and 34·5 ±9·7 mmol kg−1 dw, respectively. Mean taurine contents in type I, IIA and HB fibres were 42·4 ±15-9, 203 ±12·9 and 24·7 ±15·9 mmol kg−1 dw, respectively. Higher carnosine contents in type II fibres emphasise the importance of carnosine to intra-muscular acid-base regulation. A specific role for taurine in type I fibres is unclear.  相似文献   

16.
The pharmacokinetics of orphenadrine (ORPH) following a single intravenous (i.v.) dose was investigated in six camels (Camelus dormedarius). Orphenadrine was extracted from the plasma using a simple sensitive liquid–liquid extraction method and determined by gas chromatography/mass spectrometry (GC/MS). Following i.v. administration plasma concentrations of ORPH decline bi-exponentially with distribution half-life (t1/2α) of 0.50 ± 0.07 h, elimination half-life (t1/2β) of 3.57 ± 0.55 h, area under the time concentration curve (AUC) of 1.03 ± 0.10 g/h l−1. The volume of distribution at steady state (Vdss) 1.92 ± 0.22 l kg−1, volume of the central compartment of the two compartment pharmacokinetic model (Vc) 0.87 ± 0.09 l kg−1, and total body clearance (ClT) of 0.60 ± 0.09 l/h kg−1. Three orphenadrine metabolites were identified in urine samples of camels. The first metabolite N-desmethyl-orphenadrine resulted from N-dealkylation of ORPH with molecular ion m/z 255. The second N,N-didesmethyl-orphenadrine, resulted from N-didesmethylation with molecular ion m/z 241. The third metabolite, hydroxyl-orphenadrine, resulted from the hydroxylation of ORPH with molecular ion m/z 285. ORPH and its metabolites in camel were extensively eliminated in conjugated form. ORPH remains detectable in camel urine for three days after i.v. administration of a single dose of 350 mg orphenadrine aspartate.  相似文献   

17.
Intravenous infusions of hydrocortisone sodium succinate (HSS) were given at 0·625 mg kg−1 hour−1 and 0·312 mg kg−1 hour−1 to six dogs. Plasma cortisol concentrations were measured by radioimmunoassay at 0, 15, 30, 45 and 60 minutes and then every 30 minutes for a further five hours. Chronic hypocortisolaemia was induced and maintained with mitotane and the HSS infusions were repeated after 31 and 50 days. No statistically significant difference was observed in the plasma cortisol concentrations after either period of hypocortisolaemia, but the plasma cortisol concentrations tended to be higher in most of the dogs.  相似文献   

18.
Gentamycin sulphate ( ) and gentamycin oleate ( ) were encapsulated in liposomes composed of phosphatidylcholine ( ) and cholesterol ( ) (molar ratio 7:7:2 and 5:5:l, respectively), and were administered via intramuscular injection to rabbits, to evaluate their potential use as sustained release formulations. Five groups of five animals each were used for the pharmacokinetic study, and treatments were established as follows: 3 mg kg−1 of i.v., 3 mg kg−1 of i.m., 3 mg kg−1 of liposome-containing gentamycin sulphate ( ) i.m., 3 mg kg−1 of i.m., and 3 mg kg−1 of liposome-containing gentamycin oleate ( ) i.m. Gentamycin plasma concentrations after i.m. administration of LGS were extremely low compared with those obtained after the i.m. administration of ; the peak plasma concentration ( max) showed an eight-fold decrease with , and the area under the concentration-time curve ( ) was four-fold lower for the liposomal form. The apparent elimination half-life estimated after administration of showed a three-fold increase compared with values calculated for free . After the administration of the same dose of , max obtained showed a 2·5-fold decrease in relation to peak concentrations of free , and the apparent β-half life of encapsulated showed a three-fold increase compared with i.m. . Large-size liposomes containing gentamycin administered i.m. to rabbits gave sustained drug release from the injection site, providing prolonged plasma concentrations of the drug in the body.  相似文献   

19.
The effects of cholecystokinin-8 (cck-8) and pentagastrin on insulin and glucagon secretion were studied in conscious sheep. Intravenous infusions of ccx-8 (3 to 1000 pmol kg−1 min−1 for 30 minutes) induced a dose-dependent increase in plasma insulin, but did not alter plasma glucagon concentration. The threshold dose of ccx-8 for stimulation of insulin secretion was 10 to 30 pmol kg−1 min−1. Pentagastrin was infused intravenously at doses of 10 to 3000 pmol kg−1 min−1. The maximal dose of pentagastrin slightly stimulated insulin, but not glucagon, secretion. The insulin secretory activity of pentagastrin was only 1/300 that of ccx-8 on a molar basis. The threshold dose of ccx-8 for stimulation of insulin secretion was similar to that for exocrine pancreatic secretion obtained in earlier studies. In conclusion, ccx is a potential candidate as a physiological factor regulating insulin secretion in sheep.  相似文献   

20.
The pharmokinetic properties of amoxycillin, and its penetration into respiratory tract tissue, were determined in 18 Actinobacillus pleuropneumoniae infected pigs, after a single i.v. dose of 8·6 mg amoxycillin kg−1 bodyweight. Pleuropneumoniae was produced experimentally in pigs by an aerosol infection model. The infection created a homogenous response, characterised by depression of breathing and increased body temperature. The clinical symptoms were accompanied by increased haptoglobin levels and circulating white blood cell counts. At necropsy the findings were characterised by a bilateral fibrinous pleuropneumonia. Twenty hours after infection, the pigs were administered amoxycillin i.v. The plasma concentration-time curve was described by a three compartment open model. The mean residence time and the elimination half-life were l·5 and 3·4 hours, respectively. The steady-state volume of distribution was 0·67 litres kgl, and the clearance was 0·46 litres kg−1 hour−1. There were no significant differences between these values and those reported previously for healthy pigs. The concentration of amoxycillin in bronchial secretions, lung tissue and diseased lung tissue peaked two hours after intravenous drug administration, while amoxycillin concentration in pleural fluid, lymph nodes and tonsil tissue peaked at the first sampling point one hour after drug administration. The concentration of amoxycillin in secretions and tissue decreased by a slower rate than amoxycillin concentration in plasma, resulting in an increasing tissue-to-plasma concentration ratio. The distribution ratios (AUCtissue/JAUCplasma) was 0·53 for bronchial secretions, 0·44 for pneumonic lung tissue, 0·42 for lung tissue, 1·04 for pleural fluid, 0·58 for lymph nodes and 0·37 for tonsil tissue. The distribution of amoxycillin to secretions was increased compared with that previously reported for healthy pigs, while only minor changes were observed in lung tissue.  相似文献   

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