Vaziri N D, Barbari A, Hollander D, Vincent T, Tran L, Oveisi F, Pahl M V, Bissar L
Department of Medicine, University of California, Irvine 92717.
Proc Soc Exp Biol Med. 1989 Feb;190(2):150-4. doi: 10.3181/00379727-190-42842.
Earlier studies have revealed an impairment of jejunal absorption of long chain fatty acids in experimental uremia. We investigated the intestinal absorption of butyric acid which is a short chain fatty acid in experimental renal failure (RF). Sprague-Dawley rats were randomized into the RF group which had subtotal nephrectomy, a sham-operated control group, and a pair-fed group. In vivo recirculating perfusion (n = 5) and in vitro everted sac incubation (n = 8) were employed. The in vitro experiments were repeated substituting the serosal buffer by either predialysis or postdialysis sera from uremic individuals, or normal serum (n = 10). The rate of in vivo butyric acid absorption was significantly lower while the in vitro absorption was significantly higher in the RF group than those observed in the sham-operated and pair-fed groups which showed comparable values. The normality of butyric acid absorption in the pair-fed animals despite comparable weight loss with the RF group tends to exclude anorexia and weight loss as a cause of altered butyric acid transport in RF animals. The disparity between the in vivo and in vitro data is suggestive of an inhibitory influence of uremic environment which is present in vivo and absent in vitro. This viewpoint was corroborated by the observed fall in butyric acid absorption by sacs containing predialysis uremic serum as compared with those containing normal or postdialysis sera. The latter further suggests that the inhibitory factor(s) is dialyzable.
早期研究显示，实验性尿毒症患者空肠对长链脂肪酸的吸收存在障碍。我们研究了实验性肾衰竭（RF）中短链脂肪酸丁酸的肠道吸收情况。将Sprague-Dawley大鼠随机分为接受次全肾切除术的RF组、假手术对照组和配对喂养组。采用体内再循环灌注（n = 5）和体外翻转肠囊孵育（n = 8）的方法。体外实验重复进行，分别用尿毒症患者透析前或透析后的血清替代浆膜缓冲液，或用正常血清（n = 10）。RF组体内丁酸吸收速率显著低于假手术组和配对喂养组，而体外吸收速率则显著高于假手术组和配对喂养组，后两组的数值相当。配对喂养动物的丁酸吸收正常，尽管其体重减轻程度与RF组相当，这倾向于排除厌食和体重减轻是RF动物丁酸转运改变的原因。体内和体外数据的差异表明尿毒症环境在体内存在抑制作用，而在体外不存在。与含有正常或透析后血清的肠囊相比，含有透析前尿毒症血清的肠囊丁酸吸收下降，这证实了上述观点。后者进一步表明抑制因子是可透析的。
