title: Involvement of calcium in cyclic nucleotide metabolism in human vascular smooth muscle.
abstract: When cyclic nucleotide phosphodiesterase was purified from isolated smooth muscle layer of human aorta by DEAE-cellulose column chromatography, separated cyclic GMP phosphodiesterase activity was markedly stimulated in the presence of 10-20 micrometer of Ca2+ by a protein modulator which has similar physicochemical properties to troponin C. Synthetic compound, N-(6-aminohexl)-5-chloro-1-naphthalensulfonamide, which produced relaxations of arteries contracted by prostaglandin F2alpha or KCl was found to inhibit selectively this Ca2+-dependent cyclic GMP phosphodiesterase. This compound produced inhibition of superprecipitation of myosin B system obtained from mouse skeletal muscle and also inhibited adenosine triphosphatase activity of myosin B. Our data suggest that calcium is involved through a protein modulator in cyclic nucleotide metabolism of vascular smooth muscle and that the calcium-dependent protein modulator probably participates in the regulation of contractile response of vascular smooth muscle by affecting actomyosin ATPase activity.
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism*; D000205:Actomyosin / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000201:enzymology; D001158:Arteries / Q000378:metabolism*; D002118:Calcium / Q000502:physiology*; D002848:Chromatography, DEAE-Cellulose; D000242:Cyclic AMP / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000201:enzymology / Q000378:metabolism*; D009282:Naphthalenesulfonates / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology; D011817:Rabbits
chemical_list: D009282:Naphthalenesulfonates; D011460:Prostaglandins F; D000205:Actomyosin; D000242:Cyclic AMP; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D000251:Adenosine Triphosphatases; D006152:Cyclic GMP; D002118:Calcium