AJP - Renal Physiology, Vol 244, Issue 2 205-F209, Copyright © 1983 by American Physiological Society
Renal response to AVP and DDAVP after angiotensin II blockade in the rat
G. Fejes-Toth, T. Zahajszky and J. Filep
Inhibition of the renin-angiotensin system with saralasin or with SQ 20,881
was used to examine a possible interaction between endogenous angiotensin
II and antidiuretic hormone in renal water excretion. In sodium-depleted
anesthetized rats undergoing water diuresis, neither saralasin nor SQ
20,881 had any significant effect on water excretion. Both drugs, however,
markedly potentiated the antidiuretic response to arginine vasopressin. A
similarly enhanced antidiuresis was also observed when the renal response
to 1-desamino-8-D-arginine vasopressin was investigated in the presence or
absence of saralasin. There were no significant changes in sodium or
potassium excretion or in glomerular filtration rate in any of the groups
studied. Neither was there any interaction of the drugs with relation to
blood pressure. These results seem to indicate that endogenous angiotensin
II is capable of antagonizing the hydroosmotic effect of antidiuretic
hormone.
