Cyclic Nucleotides and Vasoactive Intestinal Peptide Production in a Rabbit Model of Escherichia Coli Septicemia

ABSTRACT Nitric oxide and vasoactive intestinal peptide (VIP) are potent vasodilators and postulated as inducers of hypotension. These mediators activate guanylate cyclase and adenylate cyclase, respectively, with subsequent biosynthesis of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) producing vascular smooth muscle relaxation and vasodilatation. Cyclic nucleotides and VIP were evaluated during Escherichia coli septicemia in two groups of rabbits; 1) sepsis alone and 2) sepsis and a competitive inhibitor of nitric oxide synthase, NG-monomethyl-L-arginine. Arterial blood was obtained for determination of bacteremia, lactic acidemia, nucleotides, nitrites, and VIP levels. Significant bacteremia, endotoxemia, tachycardia, lactic acidosis, and hypotension occurred in all animals ( P P P