Kim S W, Rogers Q R, Morris J G
Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis 95616, USA.
J Nutr. 1996 Feb;126(2):509-15. doi: 10.1093/jn/126.2.509.
In a crossover design, cats were fed a canned heat-processed diet (18 g dry matter/kg initial body wt) either with (+) or without (-) antibiotics [a mixture of penicillin G, procaine (25 mg/18 g diet) and tetracycline (50 mg/18 g diet)]. The (-/+) group received no antibiotics during the first 5-wk period and received antibiotics during the second 5-wk period; the (+/-) group received the reverse. Plasma, whole blood, urinary and fecal concentrations of taurine, fecal bile acid excretion and cholyltaurine hydrolase activities were measured. Consumption of antibiotics for 5 wk resulted in a lower rate of depletion of plasma taurine. Taurine concentrations decreased more over the first 5 wk in cats in the (-/+) group than in cats in the (+/-) group [from 116 +/- 26 to 26 +/- 6 mumol/L (-/+) and from 109 +/- 6 to 77 +/- 7 mumol/L (+/-) for plasma, and from 546 +/- 8 to 292 +/- 29 mumol/L (-/+) and from 560 +/- 11 to 431 +/- 20 mumol/L (+/-) for whole blood]. Urinary total taurine excretions during the 5th week were 54 mumol/d for the (-/+) group and 135 mumol/d for the (+/-) group (pooled SEM, +/- 13). Fecal total taurine excretions during the 5th week were 184 and 53 mumol/d for the (-/+) and (+/-) groups, respectively, (pooled SEM +/- 9). Most of the fecal taurine was unconjugated (free). Fecal bile acid excretions during the 5th week were 235 +/- 18 and 106 +/- 11 mumol/d for the (-/+) and (+/-) groups, respectively. Dietary antibiotics suppressed fecal cholyltaurine hydrolase activity of cats. Fecal cholyltaurine hydrolase activities during the 5th week were 279 +/- 54 and 42 +/- 10 nmol cholic acid released.min-1.g dry feces-1 in the (-/+) and (+/-) groups, respectively. After the crossover, mean values for the groups were reversed, showing that the observed changes were due to the antibiotic treatment. These results support the hypothesis that the dietary taurine requirement of cats is largely determined by the extent of microbial degradation of taurine in the gastrointestinal tract.
在交叉设计中，给猫喂食罐装热加工日粮（18克干物质/千克初始体重），日粮中添加（+）或不添加（-）抗生素[青霉素G、普鲁卡因（25毫克/18克日粮）和四环素（50毫克/18克日粮）的混合物]。（-/+）组在最初5周期间不使用抗生素，在第二个5周期间使用抗生素；（+/-）组则相反。测量了血浆、全血、尿液和粪便中牛磺酸的浓度、粪便胆汁酸排泄量以及胆酰牛磺酸水解酶活性。使用抗生素5周导致血浆牛磺酸的消耗率降低。（-/+）组猫在最初5周内牛磺酸浓度的下降幅度大于（+/-）组猫[血浆中，（-/+）组从116±26微摩尔/升降至26±6微摩尔/升，（+/-）组从109±6微摩尔/升降至77±7微摩尔/升；全血中，（-/+）组从546±8微摩尔/升降至292±29微摩尔/升，（+/-）组从560±11微摩尔/升降至431±20微摩尔/升]。第5周期间，（-/+）组的尿总牛磺酸排泄量为54微摩尔/天，（+/-）组为135微摩尔/天（合并标准误，±13）。第5周期间，（-/+）组和（+/-）组的粪便总牛磺酸排泄量分别为184和53微摩尔/天（合并标准误±9）。大部分粪便中的牛磺酸是未结合的（游离的）。第5周期间，（-/+）组和（+/-）组的粪便胆汁酸排泄量分别为235±18和106±11微摩尔/天。日粮抗生素抑制了猫粪便中的胆酰牛磺酸水解酶活性。第5周期间，（-/+）组和（+/-）组的粪便胆酰牛磺酸水解酶活性分别为279±54和42±10纳摩尔胆酸释放·分钟-1·克干粪便-1。交叉后，两组的平均值颠倒，表明观察到的变化是由于抗生素治疗引起的。这些结果支持了这样的假设，即猫日粮中牛磺酸的需求量很大程度上取决于胃肠道中牛磺酸的微生物降解程度。
