Abstract
This study examines the effect of in vivo modulation of Na+-H+ exchange activity on the development of Na+-K+-ATPase in rat kidney proximal convoluted tubule (PCT) segments. To stimulate Na+-H+ exchanger (major entry pathway for Na in PCT), weanling rats were fed NH4Cl for 4 days to induce metabolic acidosis (MA). In vehicle (Vh)-fed rats PCT Na+-K+-ATPase activity (pmol Pi.mm tubule-1.h-1 +/- SE) increased from 481 +/- 78 at 16 days to 1,122 +/- 119 at 20 days. In 20-day-old chronic MA rats, PCT Na+-K+-ATPase activity was 1,717 +/- 109, i.e., significantly higher (P less than 0.01) relative to controls. Chronic MA had no effect on PCT Mg ATPase activity and on Na+-K+-ATPase in the medullary thick ascending limb (MTAL). To inhibit the Na+-H+ exchanger, weanling rats received amiloride (30 micrograms.100 g body wt-1.day-1) via osmotic minipump for 4 days. In Vh-treated rats PCT Na+-K+-ATPase increased from 481 +/- 78 at 16 days to 1,428 +/- 81 at 20 days. In rats given chronic amiloride, PCT Na+-K+-ATPase was significantly lower (858 +/- 75) at 20 days relative to controls but PCT Mg ATPase and MTAL Na+-K+-ATPase activity was the same as in controls. Chronic MA and amiloride had no significant effect on PCT Na+-K+-ATPase activity in adult rats. Acute MA and acute amiloride injection had no significant effect on PCT Na+-K+-ATPase in weanling rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
