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The chiral inversion of ketoprofen has been previously demonstrated in cattle, but no studies have been performed on different ages and metabolic situations in the animals. The aim of this work was to study any modifications of the stereoconversion of ketoprofen that occur by reason of age, lactation or gestation in dairy cows. Holando Argentino cattle were divided into three groups: 8 cows in early lactation, 8 pregnant cows and 8 newborn calves. Four animals from each group received the enantiomer R-(–)-ketoprofen by intravenous administration; the other four animals received the S-(+) enantiomer, all at doses of 0.5 mg/kg. Blood samples were collected at standardized times after dosing and assayed for ketoprofen by high-performance reversed-phase liquid chromatography (HPLC). The percentage inversion of R-(–)-ketoprofen to S-(+)-ketoprofen was 50.5% (SD ± 2.4) in the preruminants, 33.3% (SD ± 1.7) in cows in early lactation and 26.0% (SD ± 5.1) in cows in gestation. These results indicate a differing enantioselective metabolic behaviour for one compound in one species under different physiological situations. 相似文献
2.
Sansinanea A Cerone S Virkel G Streitenberger S Garcia M Auza N 《Veterinary research communications》2000,24(8):517-525
The objectives of this study were to evaluate the activity of antioxidant systems in the hepatic tissues of steers experimentally subjected to a restricted diet. Hence, the activities of superoxide dismutase (SOD) and reduced glutathione (GSH) and lipid peroxide levels were measured. Nine male Holstein steers were used. They were separated in two groups: three steers in group 1 (control) and six steers in group 2, which were subjected to a restricted diet that covered only 60% of the maintenance requirements. After 30 days, the animals in both groups were killed and studies were completed. Both the CuZn-SOD and the glucose-6-phosphate dehydrogenase activities were significantly decreased (p<0.05) in group 2, reaching 68% and 60%, respectively, of the concentrations found in group 1. The concentration of GSH in group 2 was 6.71±0.9 nmol/mg protein, which was significantly lower (p<0.01) than that of the controls, 25.7±2.4 nmol/mg protein. In addition, the lipid peroxide levels were significantly increased (p<0.01) in group 2, being 50–60% higher than that in group 1. These results showed that the poor nutritional status caused modifications to the enzymatic antioxidant systems, with a lower ability to reduce oxidative compounds and a state of lipid peroxidation. 相似文献
3.
反刍家畜铜中毒的诊断与治疗 总被引：1，自引：0，他引：1
绵羊是对铜毒副作用最敏感的畜种。绵羊的铜中毒可分为慢性或急性中毒,取决于给铜的剂量和持续的时间。Boughton等1934年首次报道绵羊的铜中毒。他们证实,喂含铜的矿物质添加剂几周或数月的绵羊,会发生一种快速死亡的急性病,该病与红细胞迅速遭受破坏、突发血色素血症、黄疸和血红蛋白尿有关,患羊在出现危象的几天内死亡。牛铜中毒见于幼犊,当口服丸剂或非肠道给予某种混合物以补铜时多见。在一份报告中,作者推测慢性铜中毒是造成娟珊母牛死亡的原因。还有一些关于奶牛铜中毒的报道。Stogdale注意到在缺铜草地放牧而饲喂添加铜的燕麦的成年… 相似文献
4.
C. F. Machado † S. T. Morris J. Hodgson H. Berger ‡ N. J. Auza † 《Grass and Forage Science》2006,61(4):385-397
This study investigated the effects of levels of supplementation with maize grain and herbage allowance (HA) on grass herbage and maize intake, animal performance and grazing behaviour in two replicated grazing experiments with Angus beef cattle in Argentina. In Experiment 1, the response to increasing HA (2·5, 5·0 and 7·5 kg DM herbage 100 kg?1 live weight (LW) d?1 with and without 0·5 kg DM maize grain 100 kg?1 LW d?1) was investigated. In Experiment 2, the responses to level of maize grain offered (0, 0·5 and 1·0 kg DM maize grain 100 kg?1 LW d?1) at an HA of 2·5 kg DM herbage 100 kg?1 LW d?1 and an HA of 5·0 kg 100 kg?1 LW d?1 without maize grain were assessed. In Experiment 2, soyabean meal was added to control the crude protein concentration in the diet. Two methods were used for intake estimations: pre‐ and post‐feeding herbage mass difference, and the use of the n‐alkane and 13C technique. The latter predicted most accurately the metabolizable energy requirements calculated from live weights and liveweight gain of beef cattle attained in each treatment in both experiments. Increasing HA significantly increased herbage intake and liveweight gain (P < 0·01), and general quadratic relationships between these variables could be fitted across experiments despite differences in animal and pasture characteristics. Increasing the amount of maize grain offered significantly reduced herbage intake and grazing time, but increased liveweight gain and digestibility of the diet. Substitution rate increased with increasing HA in Experiment 1 but was not affected by level of maize supplementation in Experiment 2. These relationships will aid the development of grazing management models for Argentinean conditions. 相似文献
5.
M.A. Aba M.A. Quiroga N. Auza M. Forsberg H. Kindahl 《Reproduction in domestic animals》1999,34(6):471-476
Contents Progesterone and progestogens have proved to be effective in controlling follicle development and synchronization of ovarian activity in different species. In this study, vaginal sponges containing 120 mg medroxyprogesterone acetate were used to synchronize ovarian activity in llamas and to predict the time when a mature follicle will be present. Plasma concentrations of oestradiol-17β and progesterone were measured to determine follicle and corpus luteum development. The sponges were kept in the vagina for 9 days. Six days after sponge withdrawal, ovulation was induced by either GnRH injection (n = 4), mating with a vasectomized male (n = 8) or mating with an intact male (n = 10). Plasma progesterone concentrations varied between animals until day 6 after insertion of the sponges. Thereafter, progesterone levels remained close to the detection limit of the assay until ovulation was induced. The mean oestradiol-17β plasma concentration reached its lowest value 3–4 days after insertion of the sponges. Thereafter, concentrations increased and reached peak levels at day 6 after withdrawal of the sponges. All animals ovulated and developed a corpus luteum with a normal life span after the ovulatory stimulus. Blood samples were collected frequently after mating to evaluate the endocrine response to copulation. Plasma concentrations of PGF2α metabolite and cortisol increased in parallel after copulation. The metabolite concentrations returned to basal levels 3–4 h after mating whereas the cortisol concentrations remained elevated for about 12 h after copulation The luteinizing hormone secretory pattern resembled that reported when llamas with a mature ovulatory follicle were mated. In conclusion, the protocol evaluated in this study was shown to be useful for the synchronization of ovarian activity and for predicting the time when an ovulatory follicle will be present in llamas. 相似文献
6.
The aim of the study was to evaluate the pharmacokinetics of flurbiprofen (FBP) in different age groups and physiological
status groups in dairy cattle. Ten Argentine Holstein bovines were divided into three different groups: 3 cows in early lactation,
3 cows in gestation and 4 newborn calves. Based on previous experience, all the animals received racemic FBP (50:50) at a
dose of 0.5 mg/kg by intravenous administration. Blood samples were taken at predetermined times after administration of flurbiprofen.
Plasma enantiomer concentrations were measured by HPLC. Total body clearance (ClB) of (S)-(+)-FBP was higher in calves than in cows (114.5, 136.4, 121.4, 128.9 μg/ml vs 22.0, 24.2, 46.5 μg/ml and 27.6, 25.3, 34.6
μg/ml). In calves the disposition kinetics showed stereoselective behaviour. Area under the concentration–time curve (AUC)
was higher and ClB and steady-state volume of distribution (Vss) were lower for (R)-(−)-FBP than for (S)-(+)-FBP. In cows, stereoselectivity was observed in ClB and elimination half-life
(fract12)(frac{t_1}{2})
only in the early lactation group. In this study, enantioselective metabolic behaviour of FBP under the physiological situations
studied was found. Hence, it is possible that both enantiomers of flurbiprofen may contribute to the drug's therapeutic effects,
but further studies with the administration of separate enantiomers will be required to elucidate their metabolism. 相似文献
7.
Some Pharmacokinetic Parameters of R-(–)- and S-(+)-Ketoprofen: The Influence of Age and Differing Physiological Status in Dairy Cattle 总被引：1，自引：0，他引：1
The pharmacokinetic parameters of ketoprofen have previously been studied in cattle, but no studies have been performed on differing ages and metabolic situations in these animals. The aim of this work was to study the possible modifictions of the pharmacokinetics of ketoprofen enantiomers that may result from age, lactation or gestation in dairy cattle. Three groups of Holando Argentino cattle contained, respectively, 8 cows in early lactation, 8 pregnant cows and 8 newborn calves. Four animals from each group received the enantiomer R-(-)-ketoprofen, the other four animals received the S-(+) enantiomer, all by intravenous injection at a dose of 0.5 mg/kg. Significant differences between the three categories of animals were obtained in elimination half-life (t1/2) (1.52, 0.87 and 0.31 and 1.71, 0.69 and 0.26 in newborn calves, cows in early lactation and cows in gestation, respectively), mean residence time (MRT) (0.45, 1.25, 2.20 and 0.38, 0.99, 2.47 h, in cows in gestation, cows in early lactation and newborn calves, respectively) and area under the plasma concentration-time curve (AUC) (0.87, 2.93, 3.24, and 0.67, 2.78, 5.13 (microg/h)/ml in cows in gestation, cows in early lactation and newborn calves, respectively, for the R-(-) and S-(+) enantiomer, respectively. In calves, there was a significant difference in AUC (3.24 vs 5.13 (microg/h)/ml between R-(-)- and S-(+)-ketoprofen. In view of the differences between calves and adult cattle in the pharmacokinetic results for ketoprofen, the effects of age and physiological status (lactation, gestation) should be taken into account for therapeutic regimens. 相似文献
8.
Cerone S.I. Sansinanea A.S. Streitenberger S.A. Garcia M.C. Auza N.J. 《Veterinary research communications》1998,22(1):47-57
Six female cattle were given molybdenum (30 ppm) and sulphate (225 ppm) to induce experimental secondary copper deficiency. The total and differential leukocyte numbers and lymphocyte subpopulations were counted and the neutrophil activity was assessed by means of nitroblue tetrazolium reduction and phagocytosis of sheep erythrocytes. The serum caeruloplasmin activity and concentration were also determined. Copper deficiency was confirmed from decreased serum copper levels, the animals with values less than 5.9 µmol/L being considered deficient. Total leukocyte numbers were not affected by the copper deficiency. However, differential counts showed a marked increase in monocyte subpopulations, a significant decrease in B lymphocytes and reduced neutrophil activity. The serum caeruloplasmin activity was decreased about 50%, but the total serum protein concentration was less altered. We concluded that the effect of these changes on the animals' immune competence may contribute to a greater incidence of infectious diseases in copper-deficient cattle. 相似文献
9.
Diagnosis and treatment of copper toxicosis in ruminants. 总被引：15，自引：0，他引：15
N J Auza W G Olson M J Murphy J G Linn 《Journal of the American Veterinary Medical Association》1999,214(11):1624-1628
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