Investigation of tramsporting property of amino acid and glucose in the rat intestinal epithelial ER.

采用减分法从大鼠肠粘膜细胞中获得内质网富集微粒体，研究氨基酸和葡萄糖的转运特性。Nacl梯度对l -丙氨酸和d -葡萄糖摄取的时间过程没有影响，数据表明这些微粒体对介质渗透压变化的响应反映了这些底物膜的扩散或结合。小鼠和豚鼠肠道内质网中G-6-Pase的比活性比大鼠高10倍，其中内质网中G-6-Pase的比活性与匀浆无显著差异，而非匀浆中酰基辅酶a：单甘油酯酰基转移酶的活性比匀浆高5倍。上述结果提示，大鼠小肠内质网在氨基酸和葡萄糖的转运中起不重要作用，酰基- goa单甘油酯酰基转移酶是大鼠小肠内质网较理想的转运酶，而G-6-Pase则不理想。

The endoplasmic reticulum (ER) -enriched microsomes were obtained from rat intestinal mucosal cells by a subfractionation technique to investigate transporting property of amino acids and glucose. Nacl gradient had no effect on the time course of L-alanine and D-glucose uptakes, and the data suggested that the response to medium osmolarity chamges of these microsomes reflected diffusion or binding to the membrane of thes substrates. also, D-glucose binded to the memlrane than L-alanine The specific activities of G-6-Pase in intestinal ER of mouse and guinea pig were ten-fold higher than that of rat , in which the specific activity of G-6-Pase of ER was not significantly different from the homogenate But Acyl-CoA:monoglyceride acyltransferase activity in the not ERwas five-fold higher than that of homogenate. These results suggeoted that ER of the rat inteotinal epithel:um is not important in transport of amino acid and glucose and that Acyl-GoA:monoglyceride acyltransferase is a satisfactory morker enzyme for ER of the rat small intestine, but G-6-Pase not.