Effects of nitric oxide-related compounds and carperitide on hemodynamics and hematocrit in anesthetized rats

Sodium nitroprusside, nitroglycerin and carperitide (alpha-human ANP) all reduced mean blood pressure, but only carperitide increased the hematocrit in rats with bilateral renal artery- and ureter-ligation. NG-Monomethyl-L-arginine, a selective inhibitor of nitric oxide synthesis, elevated the mean blood pressure but did not change the hematocrit significantly. These findings suggest that ANP has a physiological role in regulating circulatory blood volume distinct from that of NO, although both increase intracellular cyclic GMP in the vasculature.