Park T, Rogers Q R, Morris J G, Morris J P
Department of Physiological Sciences, University of California, Davis 95616.
J Nutr. 1991 Feb;121(2):215-22. doi: 10.1093/jn/121.2.215.
Kittens adapted to a purified control diet containing 43.5% soy protein plus 0.15% taurine were randomly divided into three groups: control, acid-loaded or alkali-loaded. For dietary acid or alkali loadings, 2% NH4Cl or 0.87% NaHCO3 plus 0.87% KHCO3 were added to the control diet. Acid-loaded, control and alkali-loaded kittens had venous blood pH of 7.33 +/- 0.01, 7.37 +/- 0.02 and 7.39 +/- 0.02, and urine pH of 5.5 +/- 0.1, 7.2 +/- 0.1 and 8.1 +/- 0.1, respectively. After 6 wk of the dietary treatment, the plasma taurine concentrations of acid-loaded, control and alkali-loaded kittens were 74 +/- 4, 77 +/- 7 and 87 +/- 8 mumol/L (P greater than 0.05) respectively. Compared with the control group, dietary acid or alkali loading did not significantly change the taurine uptake by brush border membrane vesicles (BBMV) when BBMV were at the same in vitro pH (7.35). However, when the pH of the medium was changed to 8.0 for the alkali-loaded group or to 5.5 for the acid-loaded group, the initial taurine uptake was significantly elevated (55%) or decreased (31%) (P less than 0.05), respectively, compared with the values for the control group at pH 7.35. When BBMV prepared from the same group were tested at different pH levels (8.0 vs. 7.35 vs. 5.5), the initial uptake significantly increased (30%) at pH 8.0 and decreased (37%) at pH 5.5 compared with that observed at pH 7.35 (P less than 0.05), regardless of the acidity of the diet.(ABSTRACT TRUNCATED AT 250 WORDS)
将适应于含有43.5%大豆蛋白加0.15%牛磺酸的纯化对照饮食的小猫随机分为三组：对照组、酸负荷组或碱负荷组。对于饮食酸或碱负荷，在对照饮食中添加2%氯化铵或0.87%碳酸氢钠加0.87%碳酸氢钾。酸负荷组、对照组和碱负荷组小猫的静脉血pH值分别为7.33±0.01、7.37±0.02和7.39±0.02，尿pH值分别为5.5±0.1、7.2±0.1和8.1±0.1。饮食处理6周后，酸负荷组、对照组和碱负荷组小猫的血浆牛磺酸浓度分别为74±4、77±7和87±8μmol/L（P>0.05）。与对照组相比，当刷状缘膜囊泡（BBMV）处于相同的体外pH值（7.35）时，饮食酸或碱负荷并未显著改变BBMV对牛磺酸的摄取。然而，当将碱负荷组培养基的pH值变为8.0或酸负荷组变为5.5时，与pH值为7.35时对照组的值相比，初始牛磺酸摄取分别显著升高（55%）或降低（31%）（P<0.05）。当在不同pH水平（8.0对7.35对5.5）测试同一组制备的BBMV时，与在pH值7.35时观察到的情况相比，在pH值8.0时初始摄取显著增加（30%），在pH值5.5时降低（37%）（P<0.05），与饮食的酸度无关。（摘要截短至250字）
