EFFECTS OF SODIUM NITROPRUSSIDE, NITROGLYCERIN, AND SODIUM AZIDE ON LEVELS OF CYCLIC NUCLEOTIDES AND MECHANICAL-ACTIVITY OF VARIOUS TISSUES

  • 1 January 1977
    • journal article
    • research article
    • Vol. 3  (4) , 239-247
Abstract
Three agents that activate guanylate cyclase, sodium nitroprusside, nitroglycerin and sodium azide, were examined for their effects on cyclic[c]GMP and cAMP accumulation and muscle motility with several tissues. All of these agents, except nitroglycerin with ventricle preparations, increased cGMP levels and did not alter cAMP in incubations of preparations of bovine tracheal smooth muscle, guinea pig tracheal chains, taenia cecum, atria and ventricle, and rat liver and cerebral cortex. Increases in cGMP with these agents occurred with relaxation of smooth muscle preparations and without alteration in the contractility of atrial preparations. The hypothesis is supported that cGMP accumulation in smooth muscle may be related to relaxation rather than contraction as proposed previously. Relaxation with these agents is not associated with alterations in cAMP levels. Increases in cGMP levels in atrial preparations can also occur without changes in contractile force or rate of contraction.