Hara H, Fujibayashi A, Ando Y, Tamura K, Kiriyama S
Department of Bioscience and Chemistry, Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Proc Soc Exp Biol Med. 1993 Mar;202(3):315-9. doi: 10.3181/00379727-202-43541.
Absorption of a slowly digestible peptide, oligo-L-methionine (OM), added to a low casein diet was faster than absorption of OM added to a low soybean protein isolate diet in early stages of feeding in chronic portal-cannulated rats. In the present study, the gastric digestion of 14C-labeled OM in rats fed a casein-based diet was higher than that in rats fed an soybean protein isolate-based diet 30 min and 3 hr after feeding. In rats with chronic bile-pancreatic juice diversion from the proximal small intestine, the higher gastric solubilization of OM in the stomach of the casein group was also observed, but the contents of soluble digest of OM in the stomach were lower than those in the normal rats. The portal absorption of OM in the casein group was higher than in the soybean protein isolate group both 30 min and 4 hr after feeding in the bile-pancreatic juice-diverted rats, and the difference of the portal absorption between the diet groups corresponded to the difference of the amount of solubilized OM in the upper small intestine; this, in turn, depends on pepsin digestion in the stomach. These findings suggest that the difference between the two diet groups in the ability to digest OM in the stomach can at least partly explain the higher portal absorption of OM in the casein group in the early stages of feeding.
在慢性门静脉插管大鼠的喂食早期，添加到低酪蛋白饮食中的一种消化缓慢的肽——低聚-L-甲硫氨酸（OM）的吸收速度，比添加到低大豆分离蛋白饮食中的OM吸收速度更快。在本研究中，喂食基于酪蛋白饮食的大鼠在喂食后30分钟和3小时，14C标记的OM的胃消化率高于喂食基于大豆分离蛋白饮食的大鼠。在近端小肠进行慢性胆汁-胰液转流的大鼠中，也观察到酪蛋白组大鼠胃中OM的更高溶解度，但胃中OM的可溶性消化物含量低于正常大鼠。在胆汁-胰液转流的大鼠中，喂食后30分钟和4小时，酪蛋白组中OM的门静脉吸收高于大豆分离蛋白组，饮食组之间门静脉吸收的差异与上段小肠中溶解的OM量的差异相对应；而这又取决于胃中的胃蛋白酶消化。这些发现表明，两个饮食组在胃中消化OM能力上的差异至少可以部分解释喂食早期酪蛋白组中OM更高的门静脉吸收。
