为研究膜电位与仔猪小肠刷状缘膜囊(brush border membrane vesicles,BBMV)中二肽跨膜转运之间的关系,采用膜电位诱导、体外孵育及同位素示踪技术,分别观察由缬氨霉素和羰基氰化物三氟甲氧基苯腙(carbonyl cyanide p-(Tri-fluoromethoxy)phenylhydrazone,FCCP)诱导仔猪小肠BBMV产生的K^+扩散电位(膜囊内负)和H^+扩散电位(膜囊内正)对Gly-Pro二肽跨膜转运的影响。结果表明:在有Na^+和无Na^+的状况下,K^+扩散电位均促进Gly-Pro二肽由膜囊外进入膜囊内部;H^+扩散电位抑制Gly-Pro二肽由膜囊外进入膜囊内部。结果提示:在仔猪小肠BBMV转运体系中,Gly-Pro二肽的跨膜转运具有与非Na^+的阳离子协同转运的特点。
In order to study the relation between membrane potential and transmembrane transport of dipeptide in brush border membrane vesicle(BBMV) from piglet small intestine, membrane potential inducement, in vitro incubation and isotope trace technique were used to observe the effects of K^+ diffushion potential(inside negative) induded by valinomycin and H^+ diffushion potential(inside positive) induced by Carbonyl cyanide p-(Tri-fluoromethoxy)phenylhydrazone(FCCP) on transmembrane transport of Gly-Pro dipeptide in BBMV from piglet small intestine. The results showed 1) the inside negative K^+ diffusion potential resulted in an increase in Gly-Pro transport both in the presence and absence of Na^+; 2) the inside positive H^+ diffusion potential decreased Gly-Pro transport. These results suggested that dipeptide transport into the piglet small intestine should be co-transported with a cation other than Na^+ .