首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 437 毫秒
1.
The comparative pharmacokinetics of ivermectin (IVM), between healthy and in Escherichia coli lipopolysaccharides (LPS) injected sheep, was investigated after an intravenous (IV) administration of a single dose of 0.2 mg/kg. Ten Suffolk Down sheep, 55 ± 3.3 kg, were distributed in two experimental groups: Group 1 (LPS): treated with three doses of 1 μg LPS/kg bw at ?24, ?16, and ?0.75 hr before IVM; group 2 (Control): treated with saline solution (SS). An IV dose of 0.2 mg IVM/kg was administered 45 min after the last injection of LPS or SS. Plasma concentrations of IVM were determined by liquid chromatography. Pharmacokinetic parameters were calculated based on non‐compartmental modeling. In healthy sheep, the values of the pharmacokinetic parameters were as follows: elimination half‐life (2.85 days), mean residence time (MRT) (2.27 days), area under the plasma concentration curve over time (AUC, 117.4 ng day?1 ml?1), volume of distribution (875.6 ml/kg), and clearance (187.1 ml/day). No statistically significant differences were observed when compared with the results obtained from the group of sheep treated with LPS. It is concluded that the acute inflammatory response (AIR) induced by the intravenous administration of E. coli LPS in adult sheep produced no changes in plasma concentrations or in the pharmacokinetic behavior of IVM, when it is administered intravenously at therapeutic doses.  相似文献   

2.
Effects of adding different concentrations of melatonin (10?7, 10?9 and 10?11 M) to maturation (Experiment 1; Control, IVM  + 10?7, IVM  + 10?9, IVM  + 10?11) and culture media (Experiment 2; Control, IVC  + 10?7, IVC  + 10?9, IVC  + 10?11) were evaluated on in vitro bovine embryonic development. The optimal concentration of melatonin (10?9 M) from Experiments 1–2 was tested in both maturation and/or culture media of Experiment 3 (Control, IVM  + 10?9, IVC  + 10?9, IVM /IVC  + 10?9). In Experiment 1, maturated oocytes from Control and IVM  + 10?9 treatments showed increased glutathione content, mitochondrial membrane potential and percentage of Grade I blastocysts (40.6% and 43%, respectively). In Experiment 2, an increase in the percentage of Grade I blastocysts was detected in IVC  + 10?7 (43.5%; 56.7%) and IVC  + 10?9 (47.4%; 57.4%). Moreover, a lower number and percentage of apoptotic cells in blastocysts were observed in the IVC  + 10?9 group compared to Control (3.8 ± 0.6; 3.6% versus 6.1 ± 0.6; 5.3%). In Experiment 3, the IVC  + 10?9 treatment increased percentage of Grade I blastocysts with a lower number of apoptotic cells compared to IVM /IVC  + 10?9 group (52.6%; 3.0 ± 0.5 versus 46.0%; 5.4 ± 1.0). The IVC  + 10?9 treatment also had a higher mRNA expression of antioxidant gene (SOD 2) compared to the Control, as well as the heat shock protein (HSPB 1) compared to the IVM  + 10?9. Reactive oxygen species production was greater in the IVM /IVC  + 10?9 treatment group. In conclusion, the 10?9 M concentration of melatonin and the in vitro production phase in which it is used directly affected embryonic development and quality.  相似文献   

3.
The purpose of this study was to evaluate the pharmacokinetics of cefquinome (CFQ ) following single intravenous (IV ) or intramuscular (IM ) injections of 2 mg/kg body weight in red‐eared slider turtles. Plasma concentrations of CFQ were determined by high‐performance liquid chromatography and analyzed using noncompartmental methods. The pharmacokinetic parameters following IV injection were as follows: elimination half‐life (t 1/2λz) 21.73 ± 4.95 hr, volume of distribution at steady‐state (V dss) 0.37 ± 0.11 L/kg, area under the plasma concentration–time curve (AUC 0–∞) 163 ± 32 μg hr?1 ml?1, and total body clearance (ClT) 12.66 ± 2.51 ml hr?1 kg?1. The pharmacokinetic parameters after IM injection were as follows: peak plasma concentration (C max) 3.94 ± 0.84 μg/ml, time to peak concentration (T max) 3 hr, t 1/2λz 26.90 ± 4.33 hr, and AUC 0–∞ 145 ± 48 μg hr?1 ml?1. The bioavailability after IM injection was 88%. Data suggest that CFQ has a favorable pharmacokinetic profile with a long half‐life and a high bioavailability in red‐eared slider turtles. Further studies are needed to establish a multiple dosage regimen and evaluate clinical efficacy.  相似文献   

4.
  相似文献   

5.
Oocyte maturation depends on the metabolic activity of cumulus–oocyte complex (COC) that performs nutritive and regulatory functions during this process. In this work, the enzymes [phosphofructokinase (PFK) and malate dehydrogenase (MDH)] were tested to elucidate the metabolic profile of porcine COCs during the in vitro maturation (IVM). Enzymatic activity was expressed in U/COC and U/mg protein (specific activity) as mean ± SEM. In vitro maturation was performed with 2‐oxoglutarate (5, 10 and 20 mm ) or hydroxymalonate (30, 60 and 100 mm ) inhibitors of PFK and MDH, respectively. The PFK and MDH activities (U) remained constant during maturation. For PFK, the U were (2.48 ± 0.23) 10?5 and (2.54 ± 0.32) 10?5, and for MDH, the U were (4.72 ± 0.42) 10?5 and (4.38 ± 0.25) 10?5 for immature and in vitro matured COCs, respectively. The specific activities were significantly lower after IVM, for PFK (4.29 ± 0.48) 10?3 and (0.94 ± 0.12) 10?3, and for MDH (9.08 ± 0.93) 10?3 and (1.89 ± 0.10) 10?3 for immature and in vitro matured COCs, respectively. In vitro maturation percentages and enzymatic activity diminished with 20 mm 2‐oxoglutarate or 60 mm hydroxymalonate (p < 0.05). Viability was not affected by any concentration of the inhibitors evaluated. The U remained unchanged during IVM; however, the increase in the total protein content per COC provoked a decrease in the specific activity of both enzymes. Phosphofructokinase and MDH necessary for oocyte IVM would be already present in the immature oocyte. The presence of inhibitors of these enzymes impairs the meiotic maturation. Therefore, the participation of these enzymes in the energy metabolism of the porcine oocyte during IVM is confirmed in this study.  相似文献   

6.
The secretion of acetylcholinesterase (AChE) by female and male Heligmosomoides polygyrus was studied in different in vitro culture media. AChE secretion was increased in the presence of fetal calf serum or bovine serum albumin (BSA). In the absence of crowding effects, specific AChE activity in excretion/secretion products was higher for male (2.41 ± 0.07 µmol min?1 l?1 mg?1) than for female (0.56 ± 0.04 µmol min?1 mg?1) worms but on a per nematode basis both sexes showed comparable rates of secretion. Acetylthiocholine iodide was the favoured substrate of the enzyme. When the nematodes were incubated in vitro with albendazole (ABZ), ricobendazole (RBZ), mebendazole (MBZ), levamisole (LVM), morantel (MRT) or ivermectin (IVM), at concentrations from 1 mM to 10 nM, in RPMI medium for 2 or 6 h and then transferred to a drug‐free medium (RPMI medium supplemented with 0.5 % BSA) for 24 h or continuously exposed to the drugs in supplement‐free medium (24 h), the concentration‐ and time‐dependent inhibitory effects on AChE secretion were observed. The continued exposure to the drugs for all incubation periods (with a single exception for LVM 1 mM) produced the highest levels of inhibition. Under these conditions, the concentrations inhibiting the secretion of AChE by 50 % (IC50) relative to drug‐free controls were estimated. The IC50 values ranged from 0.012 µM (IVM) to 2.96 µM (MRT). The potential of this bioassay for the selective primary evaluation of new compounds with broad‐spectrum anti‐nematodal activity is discussed.  相似文献   

7.
The alleviation of pain and prevention of suffering are key aspects of animal welfare. Unfortunately, analgesic drugs are not available for all species. White rhinoceros (Ceratotherium simum ), representing one of such species, which survive poaching attempts inflicted with severe facial injuries and gunshot wounds, nonetheless require analgesic support. To improve treatment conditions, this study explored the use of carprofen for the treatment of pain and inflammation in white rhinoceros. The pharmacokinetics of 1 mg/kg intramuscular carprofen was evaluated in six healthy white rhinoceros. The half‐life of λz and mean residence time was 105.71 ± 15.67 and 155.01 ± 22.46 hr, respectively. The area under the curve and the maximum carprofen concentration were 904.61 ± 110.78 μg ml?1 hr?1 and 5.77 ± 0.63 μg/ml, respectively. Plasma TXB 2 inhibition demonstrated anti‐inflammatory properties and indicated that carprofen may be effective for a minimum of 48 hr in most animals. With its long half‐life further indicating that a single dose could be effective for several days, we suggest that carprofen may be a useful drug for the treatment of white rhinoceros.  相似文献   

8.
The traditional stripping procedure for collecting fish semen is associated with the risk of urine contamination, which may significantly affect semen quality and quantity. The use of a catheter as an alternative method for semen collection may overcome this problem. Therefore, this study compared Caspian brown trout (Salmo trutta caspius) semen parameters (i.e. sperm density, seminal plasma osmolality, motility parameters of spermatozoa analysed using computer‐assisted sperm analysis and fertility) between the traditional stripping method and the use of a catheter. All parameter values of the semen collected with a catheter were significantly higher (p < .05; density = 7.67 ± 1.02 × 109 ml?1 and osmolality = 279.28 ± 32.84 mOsm kg?1) than those collected with stripping method (density = 4.85 ± 0.47 × 109 ml?1 and osmolality = 216.42 ± 20.75 mOsm kg?1). Semen collected with a catheter was characterized by higher spermatozoa motility compared with sperm collected via stripping. Similarly, the fertilization ability of sperm collected with a catheter was significantly greater (p < .05) than sperm collected with the traditional stripping method. In conclusion, collection of sperm with a catheter was shown to effectively reduce urine contamination and is therefore recommended for the collection of Caspian brown trout sperm.  相似文献   

9.
High‐density lipoprotein (HDL) is the main lipoprotein in the follicular fluid, and it has anti‐inflammatory, antioxidant and cryoprotectant properties. The anti‐inflammatory potential and antioxidant potential are derived from its lipid composition, especially the apolipoprotein AI (ApoAI) and paraoxonase 1 (PON1). The aim of this study was to evaluate the effect of HDL during in vitro maturation (IVM) on oocyte maturation and early bovine embryo development. For this, cumulus–oocyte complexes (COCs) were obtained from bovine ovaries collected at a local slaughterhouse. COCs (n = 2,250) were allocated into three groups (n = 50 COCs/group) according to the addition of HDL protein (HDL‐P) during IVM for 22 hr: 0 (control), 50 and 150 mg/dl. After IVM, COCs were inseminated (in vitro fertilization) and cultivated for 7 days. Total cholesterol concentration, total protein, triglycerides and ApoAI concentrations on IVM medium increased proportionally to HDL‐P addition. However, PON1 activity was not detected in any treatment. The addition of HDL‐P did not affect nuclear maturation rate, endogenous reactive oxygen species and glutathione levels in COCs (p > 0.05). The highest HDL‐P concentration (150 mg/dl) decreased cleavage and blastocyst rate (p < 0.05). Moreover, the HDL‐P 150 mg/dl group had lower cellular count/blastocyst than the 50 mg/dl group (p < 0.05). However, the addition of HDL‐P did not affect relative gene expression of evaluated genes. In conclusion, the complex HDL/ApoAI obtained from human plasma, in the absence of PON1 activity during in vitro oocyte maturation, decreased initial embryo development.  相似文献   

10.
Nine horses received 20 mg/kg of intravenous (LEVIV ); 30 mg/kg of intragastric, crushed immediate release (LEVCIR ); and 30 mg/kg of intragastric, crushed extended release (LEVCER ) levetiracetam, in a three‐way randomized crossover design. Crushed tablets were dissolved in water and administered by nasogastric tube. Serum samples were collected over 48 hr, and levetiracetam concentrations were determined by immunoassay. Mean ± SD peak concentrations for LEVCIR and LEVCER were 50.72 ± 10.60 and 53.58 ± 15.94 μg/ml, respectively. The y ‐intercept for IV administration was 64.54 ± 24.99 μg/ml. The terminal half‐life was 6.38 ± 1.97, 7.07 ± 1.93 and 6.22 ± 1.35 hr for LEVCIR , LEVCER , and LEVIV , respectively. Volume of distribution at steady‐state was 630 ± 73.4 ml/kg. Total body clearance after IV administration was 74.40 ± 19.20 ml kg?1 hr?1. Bioavailability was 96 ± 10, and 98 ± 13% for LEVCIR and LEVCER , respectively. A single dose of Levetiracetam (LEV ) was well tolerated. Based on this study, a recommended dosing regimen of intravenous or oral LEV of 32 mg/kg every 12 hr is likely to achieve and maintain plasma concentrations within the therapeutic range suggested for humans, with optimal kinetics throughout the dosing interval in healthy adult horses. Repeated dosing and pharmacodynamic studies are warranted.  相似文献   

11.
NSAID s are often used in horses with colic syndrome during the postoperative period, due to their ability to contrast endotoxemia and to promote an analgesic and anti‐inflammatory effect. As the pharmacokinetics of a drug are often modified in unhealthy animals compared to healthy subjects, the aim of this study was to evaluate the pharmacokinetic profile of meloxicam after i.v. administration in horses undergoing laparotomy for colic syndrome. Eight horses received 0.6 mg/kg of meloxicam i.v. towards the end of surgery. Blood samples were taken at scheduled time points during the following 24 hr. The serum concentration of the drug was determined by HPLC . Terminal half‐life (6.88 ± 2.96 hr), volume of distribution at steady‐state (186.53 ± 61.20 ml/Kg) and clearance (27.91 ± 5.72 ml kg?1 hr?1) were similar to those reported in literature for healthy horses. This result suggests that no adjustment of the approved dose should be necessary when meloxicam is used to treat horses in the immediate postoperative period after surgery for colic syndrome.  相似文献   

12.
Studies were conducted to examine the possibility of preserving slaughterhouse‐derived buffalo ovaries at 4°C for 0 (control), 12 and 24 h to maintain the developmental competence of the oocytes (experiment 1), to assess the effect of incubation temperature during oocyte maturation on rates of in vitro maturation (IVM) and in vitro fertilization (IVF) of buffalo oocytes and embryo development (experiment 2), and to examine the effect of storage at 25°C for 0 (control), 4 and 8 h of frozen–thawed buffalo sperm and BO and H‐TALP as sperm processing and fertilization media on cleavage and embryo development in vitro of buffalo oocytes (experiment 3) in order to optimize the IVF technology in buffalo. Results suggested that storage of ovaries at 4°C for 12 or 24 h significantly (p < 0.05) reduced the developmental potential of oocytes. Incubation temperatures during the IVM influenced the fertilization rate but had no significant effect on maturation and subsequent embryo development. The incubation temperature of 38.5°C during IVM was found to be optimum for embryo production in vitro. Storage of frozen–thawed sperm at 25°C for 8 h significantly (p < 0.05) decreased its ability to cleave the oocytes. Sperm processed in BO medium had significantly (p < 0.05) higher ability to cleave the oocytes than the H‐TALP medium.  相似文献   

13.
The purpose of this study was to determine the pharmacokinetic profile of intravenous firocoxib in neonatal foals. Six healthy foals were administered 0.09 mg/kg firocoxib intravenously once a day for 7 days. Blood was collected for plasma firocoxib analysis using high‐performance liquid chromatography with fluorescence detection at times 0 (day 1 of study only) and 0.08, 0.25, 1, 2, 4, 6, 8, 16 and 24 hr on dose numbers 1, 5 and 7. Blood was also collected immediately prior to doses 3, 4, 5 and 7. Final samples were collected at 36, 48, 72 and 96 hr following the final dose. Noncompartmental analysis using the trapezoidal method with linear interpolation revealed a moderate half‐life (15.9 ± 9.1 hr) with a large volume of distribution at steady state (1.79 ± 0.57 L/kg) and a clearance (96.0 ± 59.2 ml h?1 kg?1) that was more rapid than that observed in adult horses.  相似文献   

14.
Melatonin may play an important role in protecting gametes and embryos from the potential harmful effects of oxidative stress. In this study, we first examined two different heat stress (HS) treatments for in vitro oocyte maturation (Experiment 1: 38.5 vs 41.0°C, during the first 20 h; Experiment 2: 38.5 vs 41.5°C, during the entire period) on bovine oocyte maturation and embryo development. Second, we tested different melatonin concentrations added to the maturation and culture medium (Experiment 3: 0, 10?12, 10?9, 10?4 m ; Experiment 4: 0, 10?3 m ), both with and without HS (38.5 or 41.5°C, respectively). In Experiment 1, the HS treatment resulted in a lower maturation rate and number of cells/blastocyst (C/B) and a higher blastocyst rate than that in the control group. In Experiment 2, oocytes/embryos from heat‐stressed oocytes (HSO) had a lower maturation, cleavage and blastocyst rates, as well as a lower C/B compared with the control. In Experiment 3, in HSO groups, 10?4 m melatonin resulted in an increased blastocyst rate compared with 0 m melatonin, with a similar blastocyst rate to the non‐HSO without melatonin. Melatonin did not have any effect in embryos from non‐HSO groups compared with the control. In Experiment 4, 10?3 m melatonin produced lower cleavage and blastocyst rates in HSO and lower blastocyst rate in non‐HSO when compared to melatonin‐untreated oocytes/embryos. In conclusion, 10?4 m melatonin was found to alleviate bovine oocytes from the harmful effects of HS.  相似文献   

15.
This study determined the pharmacokinetics, antinociceptive, and anti‐inflammatory effects of the soluble epoxide hydrolase (sEH ) inhibitor t ‐TUCB (trans ‐4‐{4‐[3‐(4‐Trifluoromethoxy‐phenyl)‐ureido]‐cyclohexyloxy}‐benzoic acid) in horses with lipopolysaccharide (LPS )‐induced radiocarpal synovitis. A total of seven adult healthy mares (n  = 4–6/treatment) were administered 3 μg LPS into one radiocarpal joint and t ‐TUCB intravenously (i.v.) at 0 (control), 0.03, 0.1, 0.3, and 1 mg/kg in a blinded, randomized, crossover design with at least 3 weeks washout between. Two investigators independently assigned pain scores (at rest, walk and trot) and lameness scores before and up to 48 hr after t ‐TUCB /LPS . Responses to touching the joint skin to assess tactile allodynia, plasma, and synovial fluid (SF ) t ‐TUCB concentrations were determined before and up to 48 hr after t ‐TUCB /LPS . Blood and SF were collected for clinical laboratory evaluations before and up to 48 hr after t ‐TUCB /LPS . Areas under the curves of pain and lameness scores were calculated and compared between control and treatments. Data were analyzed using repeated measures ANOVA with Dunnett or Bonferroni post‐test. p  < .05 was considered significant. Data are mean ± SEM . Compared to control, pain, lameness, and tactile allodynia were significantly lower with 1 mg/kg t ‐TUCB , but not the other doses. For 0.1, 0.3, and 1 mg/kg t ‐TUCB treatments, plasma terminal half‐lives were 13 ± 3, 13 ± 0.5, and 24 ± 5 hr, and clearances were 68 ± 15, 48 ± 5, and 14 ± 1 ml hr?1 kg?1. The 1 mg/kg t ‐TUCB reached the SF at high concentrations. There were no important anti‐inflammatory effects. In conclusion, sEH inhibition with t ‐TUCB may provide analgesia in horses with inflammatory joint pain.  相似文献   

16.
Objective To quantitate the dose‐ and time‐related magnitude of the anesthetic sparing effect of, and selected physiological responses to detomidine during isoflurane anesthesia in horses. Study design Randomized cross‐over study. Animals Three, healthy, young adult horses weighing 485 ± 14 kg. Methods Horses were anesthetized on two occasions to determine the minimum alveolar concentration (MAC) of isoflurane in O2 and then to measure the anesthetic sparing effect (time‐related MAC reduction) following IV detomidine (0.03 and 0.06 mg kg?1). Selected common measures of cardiopulmonary function, blood glucose and urinary output were also recorded. Results Isoflurane MAC was 1.44 ± 0.07% (mean ± SEM). This was reduced by 42.8 ± 5.4% and 44.8 ± 3.0% at 83 ± 23 and 125 ± 36 minutes, respectively, following 0.03 and 0.06 mg kg?1, detomidine. The MAC reduction was detomidine dose‐ and time‐dependent. There was a tendency for mild cardiovascular and respiratory depression, especially following the higher detomidine dose. Detomidine increased both blood glucose and urine flow; the magnitude of these changes was time‐ and dose‐dependent Conclusions Detomidine reduces anesthetic requirement for isoflurane and increases blood glucose concentration and urine flow in horses. These changes were dose‐ and time‐related. Clinical relevance The results imply potent anesthetic sparing actions by detomidine. The detomidine‐related increased urine flow should be considered in designing anesthetic protocols for individual horses.  相似文献   

17.
This work characterized the egg residual concentrations of albendazole (ABZ ) and its sulphoxide (ABZSO ) and sulphone (ABZSO 2) metabolites and evaluated their effect on egg fertility and hatchability after ABZ treatments to laying hens. Seventy hens were allocated in groups: Group‐1 was the control without treatment; Group‐2 received a single ABZ oral dose (10 mg/kg); Group‐3, ‐4 and ‐5 were treated with ABZ in medicated feed over 7 days at 10, 40, or 80 mg kg?1 day?1, respectively. Eggs were analyzed to determine the ABZ /metabolite level by HPLC or subjected to incubation to evaluate the fertility and hatchability. Only ABZSO and ABZSO 2 metabolites were quantified in egg after ABZ single oral administration with maximum concentrations of 0.47 ± 0.08 and 0.30 ± 0.07 μg/ml, respectively. ABZ and its metabolites were found in eggs after 7‐day ABZ treatments. The egg residue exposure estimated as AUC s (areas under the concentration vs . time curve) were 100.5 (ABZ ), 56.3 (ABZSO ) and 141.3 μg hr g?1 (ABZSO 2). ABZ administration did not affect the egg fertility at any dosages. Egg hatchability was not affected by ABZ treatment at 10 mg/kg in medicated feed, but it decreased when the dose was 4–8 times higher. These results should be considered when ABZ is used for deworming laying hens.  相似文献   

18.
Antioxidants have been widely used during in vitro production to decrease the negative effect of reactive oxygen species. It was reported that the complex resveratrol–methyl β‐cyclodextrin (RV ‐CD ) improves resveratrol's stability and bioavailability and increases its antioxidant activity. This study evaluates the effect of RV ‐CD during in vitro oocyte maturation (IVM ) or in vitro embryo culture (IVC ) on developmental competence and quantitative changes in gene expression of developmental important genes. In experiment 1, RV ‐CD was added to IVM media and maturation level, embryo development and oocytes, cumulus cells, and blastocysts gene expression by RT ‐qPCR were examined. In experiment 2, presumptive zygotes were cultured in SOF supplemented with RV ‐CD and embryo development and blastocysts gene expression by RT ‐qPCR were studied. A group without RV ‐CD (control?) and a group with cyclodextrin (control+) were included. No differences were found in cleavage rate or blastocyst yield between groups. However, the expression of LIPE was higher in blastocysts derived from oocytes treated with resveratrol compared with control groups (p  <  .05). Blastocysts produced by IVC with resveratrol showed that RV ‐CD could modify the expression of genes related to lipid metabolism (CYP 51A1 , PNPLA 2 and MTORC 1 ) compared with control groups (p  < .05). RV ‐CD in the IVM and IVC media could reduce accumulated fat by increasing lipolysis and suppressing lipogenesis of blastocysts.  相似文献   

19.
Bayesian population pharmacokinetic models of florfenicol in healthy pigs were developed based on retrospective data in pigs either via intravenous (i.v.) or intramuscular (i.m.) administration. Following i.v. administration, the disposition of florfenicol was best described by a two‐compartment open model with the typical values of half‐life at α phase (t 1/2α), half‐life at β phase (t 1/2β), total body clearance (Cl), and volume of distribution (V d) were 0.132 ± 0.0289, 2.78 ± 0.166 hr, 0.215 ± 0.0102, and 0.841 ± 0.0289 L kg?1, respectively. The disposition of florfenicol after i.m. administration was best described by a one‐compartment open model. The typical values of maximum concentration of drug in serum (C max), elimination half‐life (t 1/2Kel), Cl, and Volume (V ) were 5.52 ± 0.605 μg/ml, 9.96 ± 1.12 hr, 0.228 ± 0.0154 L hr?1 kg?1, and 3.28 ± 0.402 L/kg, respectively. The between‐subject variabilities of all the parameters after i.m. administration were between 25.1%–92.1%. Florfenicol was well absorbed (94.1%) after i.m. administration. According to Monte Carlo simulation, 8.5 and 6 mg/kg were adequate to exert 90% bactericidal effect against Actinobacillus pleuropneumoniae after i.v. and i.m. administration.  相似文献   

20.
The purposes of the present study were to examine the effect of naloxone, a mu‐opioid receptor (MOR) antagonist, on porcine oocyte maturation and embryo development. MOR gene was expressed in germinal vesicle (GV) and metaphase II (M‐II) porcine oocytes, one‐, four‐cell stage embryos and blastocysts. In blastocysts, MOR gene was mainly expressed in inner cell mass (ICM) cells. Supplementation of 10?8 mol/L naloxone in in vitro maturation (IVM) medium increased the maturation rate (P < 0.05). However, 10?4 mol/L naloxone reduced the maturation rate (P < 0.05) compared with the control. The presence of naloxone during IVM had no effects on fertilization status and subsequent embryonic development after in vitro culture (IVC). The addition of 10?3 mol/L dibutyryl cyclic adenosine monophosphate (dbcAMP), and 10?8 mol/L naloxone together into IVM medium increased nuclear maturation (P < 0.05) compared with the addition of either dbcAMP or naloxone alone. Supplementation with naloxone in IVC medium did not improve embryonic development. However, at the concentrations of 10?6 mol/L and 10?8 mol/L, naloxone increased the ratio of ICM to total cells in blastocysts (P < 0.05). In conclusion, at low concentration, naloxone increases maturation rate and the ratio of ICM to total cells in blastocysts. Naloxone and cAMP have a synergistic effect on oocyte maturation.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号