Rp-8-Br-guanosine-3',5'-cyclic monophosphorothioate inhibits relaxation elicited by nitroglycerin in rabbit aorta.
To ascertain whether the activation of cyclic GMP-dependent protein kinase is involved in the relaxant effects of nitroglycerin, the effects of Rp-8-Br-guanosine-3',5'-cyclic monophosphorothioate (Rp-8-Br-cGMPS), an inhibitor of activation of G-kinase by cyclic GMP, were studied. In the isolated rabbit aorta contracted by phenylephrine, Rp-8-Br-cGMPS (30 microM) competitively inhibited the relaxation elicited by 8-Br-cGMP, but not that elicited by 8-Br-cyclic AMP, indicating that Rp-8-Br-cGMPS is a specific inhibitor of activation of cyclic GMP-dependent protein kinase by cyclic GMP. The relaxation elicited by nitroglycerin was inhibited by Rp-8-Br-cGMPS.
Department of Pharmacology, Niigata University School of Medicine, Japan.
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Nakazawa
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Imai
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000187:drug effects; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004789:Enzyme Activation; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D005996:Nitroglycerin / Q000037:antagonists & inhibitors*; D011817:Rabbits; D051381:Rats; D013873:Thionucleotides / Q000494:pharmacology*
D013873:Thionucleotides; C083763:8-bromoguanosino-3',5'-cyclic monophosphorothioate; D015124:8-Bromo Cyclic Adenosine Monophosphate; C016276:8-bromocyclic GMP; D017869:Cyclic GMP-Dependent Protein Kinases; D005996:Nitroglycerin; D006152:Cyclic GMP