Article date: October 1994
By: P. Charoonroje, Y. Tokumitsu, Y. Nomura, in Volume 113, Issue 2, pages 569-575
ANP (atrial natriuretic peptides)‐ or ANP/ATP‐stimulated guanylyl cyclase activities were compared in adult (2 month old) and neonatal (5–7 day old) rat lung membrane fractions.
The enzyme activities of both membranes depended on the incubation time and ATP concentration: although the activities of both membranes were similar after a short incubation time (4 min), those in adult membranes were lower than those of neonatal membranes after longer incubation times (10 and 30 min) or at lower concentrations of ATP.
ANP/ATPγS‐stimulated guanylyl cyclase activities, which were much higher than ANP/ATP‐stimulated activites, were similar in both membranes.
ATPase activity of adult membranes was higher than that of neonatal membranes, suggesting that hydrolysis of ATP leads to a decrease of ANP/ATP‐guanylyl cyclase activity in adult membranes. Triton X‐100 enhanced and diminished ANP/ATP‐stimulated guanylyl cyclase activities of adult and neonatal membranes, respectively, and thereby abolished the adult/neonatal difference in the membrane response to ATP.
ANP‐stimulated activities of both membranes were much more activated by pre‐incubation with ATRyS than those induced by simultaneous addition of ATPγS. The former activities were decreased to levels of the latter by Triton X‐100. The latter activities were not affected by Triton X‐100.
The present results suggested that conformation of lung plasma membranes is related to activation of the ANP receptor/guanylyl cyclase system.
ANP (atrial natriuretic peptides)‐ or ANP/ATP‐stimulated guanylyl cyclase activities were compared in adult (2 month old) and neonatal (5–7 day old) rat lung membrane fractions.
The enzyme activities of both membranes depended on the incubation time and ATP concentration: although the activities of both membranes were similar after a short incubation time (4 min), those in adult membranes were lower than those of neonatal membranes after longer incubation times (10 and 30 min) or at lower concentrations of ATP.
ANP/ATPγS‐stimulated guanylyl cyclase activities, which were much higher than ANP/ATP‐stimulated activites, were similar in both membranes.
ATPase activity of adult membranes was higher than that of neonatal membranes, suggesting that hydrolysis of ATP leads to a decrease of ANP/ATP‐guanylyl cyclase activity in adult membranes. Triton X‐100 enhanced and diminished ANP/ATP‐stimulated guanylyl cyclase activities of adult and neonatal membranes, respectively, and thereby abolished the adult/neonatal difference in the membrane response to ATP.
ANP‐stimulated activities of both membranes were much more activated by pre‐incubation with ATRyS than those induced by simultaneous addition of ATPγS. The former activities were decreased to levels of the latter by Triton X‐100. The latter activities were not affected by Triton X‐100.
The present results suggested that conformation of lung plasma membranes is related to activation of the ANP receptor/guanylyl cyclase system.
DOI: 10.1111/j.1476-5381.1994.tb17027.x
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