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1.
van't Klooster, G.A.E., Blaauboer, B.J., Noordhoek, J. & van Miert, A.S.J.P.A.M. Sulfadimidine metabolism in vitro: II. comparative studies in cultured rat, goat, sheep and cattle hepatocytes. J. vet. Pharmacol. Therap. 16, 454–461.
Hydroxylation and acetylation of sulphadimidine (SDD) and the deacetylation of N4-acetyl SDD was investigated in cultured hepatocytes from male and female rats, from male and female goats and from female sheep and cattle. Significant sex differences were observed for hydroxylation of SDD in hepatocytes from rat and goat. In goat, sheep and cow hepatocytes, the hydroxylation pathway is relatively important, whereas in rat hepatocytes, acetylation is predominant. Hepatocytes of all four species deacetylated N4-acetyl SDD. In ruminant hepatocytes, deacetylating activity was of considerable importance, whereas in rat hepatocytes, it appeared a minor pathway of metabolism. Similar to the in vivo situation, formation of N4-acetyl SDD in cultured hepatocytes results from an equilibrium of acetylation and deacetylation. A good correlation was found between results in isolated hepatocytes and previous findings in vivo , both in levels of species-related activities and in acetylation-hydroxylation ratios. In conclusion, cultured hepatocytes appear a useful in vitro model to study comparative sulfonamide metabolism.  相似文献   

2.
Daily subcutaneous BST injection in lactating cows, bulls and castrated male dwarf goats did not induce significant changes in the pharmacokinetic parameters of antipyrine (AP) and sulphadimidine (SDD). Similarly, no changes were obtained after injection of slow-release BST formulations in lactating cows and non-lactating female goats. In contrast to androgenic hormones, both zeranol and proligestone had no effect upon the disposition of AP and SDD, although both synthetic hormones did induce enhanced plasma somatotropin concentrations. In goats, metabolic effects induced by zeranol and BST included significant reductions in plasma urea values, whereas plasma creatinine levels were somewhat lower after daily BST administration.  相似文献   

3.
Sulphadimidine (20 mg/kg i.v.) plasma elimination and metabolite formation were studied in intact male, castrated male, and female dwarf goats. Plasma pharmacokinetics and urinary metabolite patterns were first studied in un-treated animals. Afterwards, females and castrates were treated with a combination of testosterone-propionate (1 mg/kg) and 17P-oestradiolbenzoate(0.02 mg/kg) once every 3 days, for a period of 4 weeks. In untreated animals, males showed a considerably lower plasma clearance than females or castrates. This was accompanied by lower partial clearances for the production of two hydroxylated sulphadimidine metabolites. After hormonal treatment of females and castrates, sulphadimidine plasma clearance was significantly reduced, to values corresponding with those observed in control males. Furthermore, hydroxylation was significantly inhibited after treatment. The results indicate that sulphadimidine hydroxylation in the goat is performed by enzymes of the cytochrome P450 complex which are strongly influenced by gonadal hormones. Androgens seem to play a central role in this respect.  相似文献   

4.
The main objective of this study was to investigate the relationships between changes in plasma leptin concentration and feed intake or bodyweight in female and castrated male lambs with fattening. Four female and four castrated male lambs were used and were fed roughage and concentrate supplemented with beef tallow ad libitum for 28 weeks. Although the feed intake and bodyweight increased with fattening in both the castrated male and female lambs, they decreased at 24–28 weeks in the female lambs. At the end of fattening, the crude fat content in the muscle (loin) of the female lambs was significantly higher than in the castrated male lambs (P < 0.05), while the crude protein content in the loin and fillet meat was higher in the castrated male than in the female lambs (P < 0.05). The plasma leptin concentration showed high values at a later stage of fattening (P < 0.05). In the female lambs the plasma insulin concentration increased at a later stage of fattening (P < 0.05) and was positively correlated (P < 0.0001, r = 0.78) with plasma leptin. Plasma metabolites (glucose, nonesterified fatty acid, total cholesterol and triglyceride) concentrations were also changed with fattening. Plasma total cholesterol was positively related to plasma leptin, more closely in the female than in the castrated male lambs (in females, r = 0.63, P < 0.001; in males, r = 0.38, P < 0.01). The accumulation of body fat was probably accelerated by the consumption of a lot of concentrate feed supplemented with treated beef tallow and by the stimulation of insulin with fattening. Consequently, the plasma leptin concentration increased, especially toward the end of the fattening period. The decrease in feed intake and bodyweight after the 24th week of fattening was possibly caused by an increase in leptin that is involved in the homeostatic regulation of body energy by regulating appetite.  相似文献   

5.
The aim of this study was to investigate the influence of sex and castration of rats on liver and brain fatty acid profile and liver mRNA expression of genes involved in lipogenesis and β‐oxidation. Castration significantly increased body weight and liver index and decreased serum triglyceride content in the female rats. The fatty acid composition of the liver tissue was influenced by sex and castration. Male rats had higher content of C16:0, C18:1n7, C18:2n6 and C22:5n3, while female rats had higher content of C18:0, C20:4n6 and C22:6n3. Castration of male rats decreased differences caused by sex for C18:2n6, C20:4n6 and C22:6n3. Values for C16:1n7 were higher in the castrated male rats in comparison with all other groups. Liver phospholipids showed a distribution of fatty acids similar to the total lipids. Brain total lipids and phospholipids were not influenced by sex or castration. Castration increased ?6D gene expression in both the sexes, while ?5D and ?9D increased in females and males respectively. Gonadectomy increased expression of the FASN gene in the females and decreased CPT1 and ACOX1 gene expression in the liver tissue of male rats. The observed results of lipid peroxidation, measured by TBARS, were the lowest in the intact females in comparison with all other groups. In conclusion, sex strongly influences both SFA and PUFA in liver tissue, and castration decreases these differences only for PUFA. Castration also influences the expression of the genes involved in lipid metabolism differently in male and female rats, with an increase in lipogenic genes in female rats and a decrease in key genes for mitochondrial and peroxisomal β‐oxidation in male rats.  相似文献   

6.
日粮添加大豆黄酮对去势仔猪生长性能及有关内分泌的影响   总被引：20，自引：0，他引：20  
断奶仔猪 (公母均去势 )随机分为对照组和实验组 ,分别饲喂基础日粮和基础日粮添加 5mg/kg日粮的大豆黄酮 ,试验期持续一个月。与对照组相比 ,实验组的增重和饲料利用率均有所改善 ,但存在明显的性别差异 :雄性去势仔猪增重提高 5 9.15 % (P <0 .0 1) ,但雌性去势仔猪低 2 6 .39% (P <0 .0 5 ) ;血液胰岛素样生长因子 (IGF I)含量平均提高 2 6 .6 0 % (P <0 .0 5 ) ,公、母分别为提高 5 0 .91%和降低 9.6 6 % ;睾酮含量提高 17.4 6 % (P <0 .0 5 ) ,其中雄性提高 18.4 1% ,而雌性降低 6 .86 % ;血钙含量提高 11.78% (P <0 .0 5 ) ,其中雄、雌分别提高 17.92 % (P <0 .0 5 )和 6 .4 7%。上述实验结果表明 ,大豆黄酮对去势仔猪生长和有关激素状态表现明显的性别差异性。能够显著促进去势仔公猪生长和睾酮、IGF I分泌 ,而对雌性去势仔猪则起抑制性影响  相似文献   

7.
The in vitro biotransformation of three sulfonamides, trimethoprim and aditoprim, was studied using primary cultures of pig hepatocytes. Incubation of monolayer cultures with sulfadimethoxine (SDM), sulfamethoxazole (SMX) and 14C-sulfadimidine (SDD) resulted in the formation of the corresponding N 4-acetylsulfonamide to different extents, depending upon the molecular structure of the drug. Addition of the acetylsulfonamides to the cells showed that these compounds were deacetylated, each to a different extent. A relatively low degree of acetylation (in the case of SDD) was paralleled by extensive deacetylation (i.e. AcSDD), whereas extensive acetylation (i.e. SMX) was in concert with minor deacetylation (i.e. AcSMX). The addition of bovine serum albumin to the medium resulted in a decrease in conversion of sulfonamides as well as acetylsulfonamides. The main metabolic pathway of 14C-trimethoprim (TMP) was O -demethylation with subsequent conjugation. Two hydroxy (demethyl) metabolites were formed, namely 3'- and 4'-demethyl trimethoprim, which were both glucuronidated while 3'-demethyl trimethoprim was also conjugated with sulphate. The capacity to form conjugates with either glucuronic acid or sulphate was at least as high as the capacity for O -demethylation since more than 90% of the metabolites were excreted as conjugates in the urine of pigs. Addition of 14C-aditoprim (ADP) to the hepatocytes led to the N -demethylation of ADP to mono-methyl-ADP and di-desmethyl-ADP. During the incubation another three unknown ADP metabolites were formed. In contrast to TMP, no hydroxy metabolites or conjugated metabolites of aditoprim were formed. These in vitro results were in agreement with the in vivo biotransformation pattern of the studied sulfonamides and trimethoprim in pigs.  相似文献   

8.
Pharmacokinetics of sulfamethazine in male, female and castrated male swine   总被引：1，自引：0，他引：1  
The concentration of sulfamethazine in plasma and sulfamethazine and its metabolites in urine were compared in male, female and castrated male swine. A surgical technique for placement of catheters in the urinary bladder was used to facilitate the collection of urine in males and castrated males. The elimination rate of sulfamethazine from plasma and the excretion of parent drug and metabolites into urine did not differ significantly among females, males and castrated male swine.  相似文献   

9.
The current report aimed to characterize plasma anti‐Müllerian hormone (AMH) in bovine male pseudohermaphroditism. The blood AMH concentration in a Japanese Black male pseudohermaphrodite calf was compared with pre‐ and post‐pubertal male and female calves and castrated calves. The concentration in the case was higher than in post‐pubertal males, castrated males, and pre‐ and post‐pubertal female calves (p < .05), but similar to that in pre‐pubertal male calves. After extraction of the testes, the concentration in the case dropped to a certain extent. The extracted testes expressed AMH, as detected by immunohistochemistry. This study is the first to show the characterization of AMH in a male pseudohermaphrodite calf. AMH levels in peripheral blood might be useful to diagnose male pseudohermaphroditism in cattle.  相似文献   

10.
The fact that male cats are routinely castrated prior to full sexual maturity for behavioral reasons prompted a survey of the prevalence of these behaviors in prepubertally gonadectomized male and female cats. About 10% of the 134 male and 5% of the 152 female cats studied engaged in spraying on a frequent basis later in adult life. Problem spraying and fighting in males was of the same order of magnitude as in males castrated in adulthood after the problem behaviors had appeared. The age of prepubertal castration, ranging from 6 to 10 months, had no influence on spraying or fighting later in life. It was found that male cats are more likely to spray and fight if they are in households with female cats than with other male cats. With regard to female cats, spraying or fighting was less than that of male cats. Age at the time of gonadectomy was not a factor in their tendency to spray or fight. Possible prenatal masculinization of female fetuses by male fetuses, as revealed by littermate composition, was not a factor in the predisposition of female cats to spray or fight.  相似文献   

11.
The snail Cepaea hortensis can acetylate and hydroxylate sulphatroxazole via a pathway similar to that in man. The principal metabolic pathways, in order of decreasing rate, are hydroxylation, glucuronidation and acetylation. The slug Arion rufus also can acetylate and hydroxylate sulphatroxazole, although, in contrast to the snail, is rate of acetylation is higher than that of hydroxylation.  相似文献   

12.
Radiographs of 152 cats under four years of age were examined for evidence of physeal closure. Radiographic closure was compared between entire male, castrated male, and female (neutered and entire] cats. Physeal closure in castrated males was delayed when compared to that of entire males.  相似文献   

13.
Characterization of cytochrome P450-mediated drug metabolism in cats   总被引：2，自引：1，他引：1  
In this study we examined activities of cytochrome P450 (CYP)1A, 2C, 2D and 3A using hepatic microsomes from five male and five female cats. CYP1A, 2C, 2D and 3A activities were referred by ethoxyresorufin O-deethylation (EROD), tolbutamide hydroxylation (TBH), bufuralol 1'-hydroxylation (BLH) and midazolam 1'- and 4-hydroxylation respectively. The anti-rat CYP1A2 and CYP3A2 serum significantly inhibited EROD and midazolam 1'- and 4-hydroxylation, suggesting that EROD and midazolam 1'- and 4-hydroxylation were catalysed by CYP1A and 3A in cats respectively. Quinidine inhibited BLH in cats microsomes at quite low concentrations, suggesting that BLH was catalysed by CYP2D in cats. Tolbutamide hydroxylation activities were negligible in hepatic microsomes from both male and female cats, suggesting CYP2C activities of cats are extremely low. This suggests that CYP2C substrates should be carefully administered to cats. Although there is no sexual difference in CYP1A activities, there are differences in CYP2D and 3A activities of cats. CYP2D activities were higher (3-fold), but CYP3A activities were lower (one-fifth) in female cats. These results might suggest that CYP2D and 3A substrates should be prescribed for male and female cats using different dosage regimen.  相似文献   

14.
断奶仔猪(雌雄均去势)60头随机分为对照组和试验组,分别饲喂基础日粮和基础日粮添加5mg/kg日粮的伊普异黄酮,试验期持续1个月。与对照组相比,试验组增重提高26.3%(P<0.01),饲料利用率提高33.95%,其中雄性去势仔猪增重比雌性提高显著。血液胰岛素样生长因子(IGF-I)含量雌、雄分别提高24.72%和44.76%,平均提高33.93%;睾酮含量雌、雄分别提高40.38%和40.98%,平均提高40.68%。血钙含量试验组比对照组高14.60%,其中雌、雄分别高9.76%和19.44%。上述试验结果表明,伊普异黄酮影响神经内分泌系统,提高睾酮、IGF-I和血钙水平,从而促进去势仔猪增重,而对雄性的作用比雌性显著。  相似文献   

15.
After testosterone pretreatment of castrated goats and during the rutting season of adult entire male goats, the oxidative metabolism of sulphadimidine (SDM) was inhibited markedly compared with the castrated control state of these animals. The oxidation of the 5 position (yielding 5-hydroxysulphadimidine) and of the 6-hydroxymethyl group (yielding 6-carboxysulphadimidine) was decreased equally, with that of the methyl group at the pyrimidine side chain itself being 6-hydroxymethylsulphadimidine (CH2OH), whereas the acetylation pathway was unaffected by testosterone. The consequence of altered metabolism by testosterone was a prolongation of SDM presence in the body. Effects on protein binding of the CH2OH metabolite and on the renal clearance of SDM were also investigated.  相似文献   

16.
Androgen induces production of male effect pheromone in female goats   总被引：1，自引：0，他引：1  
Previously we showed that the primer pheromone responsible for the "male effect" was produced in specific skin regions of castrated male goats by androgen treatments. In the present study, we examined whether androgen can also induce production of the male effect pheromone in female goats. Capsules containing dihydrotestosterone (DHT) or testosterone (T) were subcutaneously implanted into six ovariectomized (OVX) goats for 28 days. Small skin samples were collected from the head and rump regions, and the pheromone activity of their ether extracts was examined using a bioassay that monitors the electrophysiological manifestation of the hypothalamic gonadotropin-releasing hormone pulse generator as multiple-unit activity. Behaviors of OVX goats towards ovary-intact estrous goats were also examined before and at the end of DHT or T treatment. Before androgen treatment, neither the head nor rump skin samples in OVX goats showed pheromone activity. DHT treatment induced pheromone activity in the head skin sample of six OVX goats and in the rump skin sample of two OVX goats. Similar results were obtained by T treatment. In addition, OVX goats treated with T showed masculine-type sexual behaviors such as courtship and mounting behaviors towards the estrous goats. These results demonstrate that androgen is capable of inducing primer pheromone activity in the female and suggest that the synthesis pathway of the male effect pheromone exists in both sexes in the goat.  相似文献   

17.
Summary

The snail Cepaea hortensis can acetylate and hydroxylate sulphatroxazole via a pathway similar to that in man. The principal metabolic pathways, in order of decreasing rate, are hydroxylation, glucuronidation and acetylation. The slug Anion rufus also can acetylate and hydroxylate sulphatroxazole, although, in contrast to the snail, is rate of acetylation is higher than that of hydroxylation.  相似文献   

18.
Perineal glands in guinea pigs are part of the sebaceous glandular complex. Their secretions are used for scent marking. This is important for social status and can be seen in both sexes and castrated males. Discrepancy exits about the existence of these glands in female guinea pigs and knowledge of the anatomical consequences of castration on the male perineal glands is sparse. To examine these uncertainties related to gender, perineal glands from 13 sexually mature pet guinea pigs were examined macro‐ and microscopically. Clear gender differences in the anatomy of perineal glands were found, and castrated males showed signs of atrophy and fatty infiltration in the glands. Females do have perineal glands, although smaller than the glands in the male. The glands are typically sebaceous with multiple excretory ducts. A macroscopic unique feature in the males was the clearly evident orifices of a large excretory duct on each side of the slightly everted perineal sac. However, the reason for this gender difference is not clear. In castrated males, the orifices were atrophied and difficult to see. In addition, the sebaceous glands of the hair follicles in the skin folds of the perineal opening were smaller and less abundant in females and castrated males. The changes in castrated males are presumably linked to the hormonal changes and decreased secretion after castration. The dense keratin layer in the perineal sac was thicker in males than in both castrated males and females and could contribute to the concrement formation seen mainly in males.  相似文献   

19.
Adipose tissue was obtained from male, female and male pigs castrated either at birth, 2 or 4 mo of age. Pigs were biopsied at 11 and 20 wk of age to obtain adipose tissue samples. Lipogenic capacity was assessed by measurement of in vitro glucose incorporation into lipids of adipose tissue slices. At 20 wk of age, males were less fat than females or males castrated either at birth or 20 mo of age. Adipocyte volume at 20 wk of age was smaller in males, females and recently castrated males (4 mo) than males castrated at birth or 2 mo of age. Lipogenic rate at 20 wk of age was lower in males than in castrated pigs; females had intermediate lipogenic rates. The results provide a partial metabolic explanation for the difference in subcutaneous fat deposition in the sexually diverse groups. There was no effect of estradiol-17 beta or testosterone in vitro on adipose tissue lipogenesis, suggesting that sex hormone effects in vivo may not be involved in short-term regulation of lipogenesis.  相似文献   

20.
Two days after castration, urinary free felinine plus N-acetylfelinine decreased 24% in male cats, but, by day 5, the concentration had not decreased to that routinely found in males that have been castrated for several months. In a second experiment, three groups of castrated adult male cats received different subcutaneous injections: control (carrier), testosterone, testosterone plus estradiol. A fourth group of intact adult female cats received a testosterone injection. Urine was collected and analysed for free felinine, N-acetylfelinine and 3-methylbutanolglutathione. Baseline blood testosterone and estradiol concentrations were low during the pre-period, but increased sharply after hormone injections. The concentration of all three urinary metabolites increased as a result of testosterone injections with estradiol not modulating the effect. The effect of testosterone was not gender dependent. The concentration of free felinine, N-acetylfelinine and 3-methylbutanolglutathione in the urine remained low in the placebo control group throughout the study. The relative molar contribution of free felinine to the total amount of felinine containing compounds increased due to testosterone treatment, while the contribution of 3-methylbutanolglutathione and N-acetylfelinine decreased. Testosterone increases free felinine, N-acetylfelinine and 3-methylbutanolglutathione excretion in castrated adult male and intact female cats, whereas estradiol does not modulate this effect.  相似文献   

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