Journal of cyclic nucleotide research 

About: Journal of cyclic nucleotide research is an academic journal. The journal publishes majorly in the area(s): Cyclase & Adenylate kinase. It has an ISSN identifier of 0095-1544. Over the lifetime, 252 publications have been published receiving 7426 citations.

Femtomole sensitive radioimmunoassay for cyclic AMP and cyclic GMP after 2'0 acetylation by acetic anhydride in aqueous solution.

Abstract: The sensitivity of radioimmunoassays for cyclic AMP and cyclic GMP has been markedly improved to readily detect femtomole (10-15) amounts in tissue extracts by acetylating the cyclic nucleotides at the 2'0 position with acetic anhydride. Acetylation of cyclic nucleotides by acetic anhydride in aqueous solution proceeds more rapidly than the hydrolysis of acetic anhydride to acetic acid thus yielding 100% acetylated cyclic nucleotide. 2'0 substituted cyclic nucleotides have greater affinity for the antibody than the parent cyclic nucleotides because the antibody has been made to a protein conjugate coupled at the 2'0 position. This simple acetylation technique makes it possible to measure cyclic AMP and cyclic GMP in minute quantities of tissue without purification or concentration of the sample.

Stimulation of guanylate cyclase by sodium nitroprusside, nitroglycerin and nitric oxide in various tissue preparations and comparison to the effects of sodium azide and hydroxylamine.

Abstract: Sodium nitroprusside, nitroglycerin, sodium azide and hydroxylamine increased guanylate cyclase activity in particulate and/or soluble preparations from various tissues. While sodium nitroprusside increased guanylate cyclase activity in most of the preparations examined, the effects of sodium azide, hydroxylamine and nitroglycerin were tissue specific. Nitroglycerin and hydroxylamine were also less potent. Neither the protein activator factor nor catalase which is required for sodium azide effects altered the stimulatory effect of sodium nitroprusside. In the presence of sodium azide, sodium nitroprusside or hydroxylamine, magnesium ion was as effective as manganese ion as a sole cation cofactor for guanylate cyclase. With soluble guanylate cyclase from rat liver and bovine tracheal smooth muscle the concentrations of sodium nitroprusside that gave half-maximal stimulation with Mn2+ were 0.1 mM and 0.01 mM, respectively. Effective concentrations were slightly less with Mg2+ as a sole cation cofactor. The ability of these agents to increase cyclic GMP levels in intact tissues is probably due to their effects on guanylate cyclase activity. While the precise mechanism of guanylate cyclase activation by these agents is not known, activation may be due to the formation of nitric oxide or another reactive material since nitric oxide also increased guanylate cyclase activity.

Forskolin: a unique diterpene activator of cyclic AMP-generating systems

Abstract: Forskolin, a diterpene of the labdane family, activates adenylate cyclase in broken cell preparations as well as in intact tissues. This activation does not require the guanine nucleotide regulatory subunit of the enzyme and probably occurs via an interaction with the catalytic subunit of adenylate cyclase. Activation of adenylate cyclase by forskolin results in marked increases in levels of intracellular cyclic AMP in a variety of eukaryotic cells. Low concentrations of forskolin which alone elicit small increases in intracellular cyclic AMP greatly potentiate hormonal activation of adenylate cyclase in a number of intact cells. Forskolin elicits cellular responses which have been proposed to be dependent o cyclic AMP as a second messenger. Forskolin, thus provides an invaluable tool for the investigation of the role of cyclic AMP in physiological responses to hormones, both through it direct activation of adenylate cyclase and through its ability to potentiate hormonal activation of adenylate cyclase.

Relaxation of bovine coronary artery and activation of coronary arterial guanylate cyclase by nitric oxide, nitroprusside and a carcinogenic nitrosoamine.

Abstract: The principal objective of this study was to test the hypothesis that nitroprusside relaxes vascular smooth muscle via the reactive intermediate, nitric oxide (NO), and that the biologic action of NO is associated with the activation of guanylate cyclase. Nitroprusside, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and NO elicit concentration-dependent relaxation of precontraced helical strips of bovine coronary artery. Nitroprusside, MNNG and NO also markedly activate soluble guanylate cyclase from bovine coronary arterial smooth muscle and, thereby, stimulate the formation of cyclic GMP. Three heme proteins, hemoglobin, methemoglobin and myoglobin, and the oxidant, methylene blue, abolish the coronary arterial relaxation elicited by NO. Similarly, these heme proteins, methylene blue and another oxidant, ferricyanide, markedly inhibit the activation of coronary arterial guanylate cyclase by NO, nitroprusside and MNNG. The following findings support the view that certain nitroso-containing compounds liberate NO in tissue:heme proteins, which cannot permeate cells, inhibit coronary arterial relaxation elicited by NO, but not by nitroprusside or MNNG; the vital stain, methylene blue, inhibits relaxation by NO, nitroprusside and MNNG; heme proteins and oxidants inhibit guanylate cyclase activation by NO, nitroprusside and MNNG in cell-free mixtures. The findings that inhibitors of NO-induced relaxation of coronary artery also inhibit coronary arterial guanylate cyclase activation suggest that cyclic GMP formation may be associated with coronary arterial smooth muscle relaxation.

Endothelium-induced relaxation by acetylcholine associated with larger rises in cyclic GMP in coronary arterial strips.

Abstract: It was previously shown that the contractile response to acetylcholine (ACh) in bovine coronary arterial strips could be separated from the accompanying rises in cGMP in an opposite manner which suggested that this nucleotide may function as a relaxation- rather than a contraction promoting agent. It was also found recently by others that rings or strips of rabbit aorta and other arteries of various species relax in response to ACh if endothelial cells are still present. The influence of endothelium on the mechanical effects as well as on rises in cGMP levels produced by ACh was therefore studied in circular strips of bovine coronary arteries with and without endothelium.