K(+)-ATPase-mediated Rb+ transport in rat collecting tubule: modulation during K+ deprivation.

摘要: To evaluate the involvement of K(+)-ATPase activity in K+ transport terminal segments rat nephron, we searched for existence a component Rb+ uptake into microdissected collecting tubule associated with this ATPase. Results indicated that is stimulated by and similar fashion it specifically inhibited imidazopyridine Sch 28080 (apparent affinity approximately 5 x 10(-7) M). In both cortical outer medullary tubules (CCT MCT) normal rats, 10(-4) M significantly initial rate uptake. 28080-sensitive these two nephron was not altered ouabain, as activity. Finally, were increased factors CCT MCT rats fed K(+)-depleted diet 3 days. segments, apparent stoichiometry 1 Rb+:1 ATP. These results demonstrate reflects pump pharmacologically to gastric H(+)-K+ pump.