AJP - Renal Physiology, Vol 245, Issue 4 512-F514, Copyright © 1983 by American Physiological Society
Aldosterone response in the turtle bladder is associated with an increase in ATP
N. Cortas, E. Abras and M. Walser
Urinary bladders from freshwater turtles, mounted as sacs, were stripped of
their serosa and submucosa. This did not alter conductance. They were
maintained in open circuit except for brief observation of short-circuit
current (SCC) every 15 min. Potential difference (PD) averaged 68 +/- 14 mV
and SCC 485 +/- 100 microA. Acetazolamide 10(-3) M increased SCC by 46 +/-
27 microA. Aldosterone 10(-7) M following acetazolamide resulted in a rise
in SCC that began at about 75 min and reached a plateau between 3 and 5 h.
SCC rose 127 +/- 15% compared with control bladder halves. ATP measured in
perchloric acid extracts 5 h after addition of aldosterone increased by 33%
(P less than 0.01) and (ATP)/(ADP) X (Pi) by 81% (P less than 0.01). These
results support the view that the stimulatory effects of aldosterone on
active sodium transport involve an increase in ATP and (ATP)/(ADP) X (Pi).
