title: Inhibition of proliferation, but not of Ca2+ mobilization, by cyclic AMP and GMP in rabbit aortic smooth-muscle cells.
abstract: The effects on cellular proliferation and Ca2+ mobilization of analogues of cyclic AMP (cAMP) and cyclic GMP (cGMP) and of agents that elevate the intracellular concentrations of cyclic nucleotides were compared in closely similar preparations of first-passage rabbit aortic vascular smooth-muscle cells. Proliferation induced by foetal-bovine serum was inhibited by 78% by 1 mM-8-bromo cAMP and by 42% by 1 mM-8-bromo cGMP. In the presence of 100 microM-isobutylmethylxanthine, 100 microM-forskolin increased intracellular cAMP concentration 5-fold and inhibited proliferation by 87%, but did not affect cGMP concentration or cell viability (ATP concentration). Similarly in the presence of 100 microM-isobutylmethylxanthine, 1 mM-SIN-1 (3-morpholinosydnonimine) elevated cGMP concentration 4-fold and inhibited proliferation by 48%, but did not affect cAMP or ATP concentration. Isobutylmethylxanthine (1 mM) elevated cAMP concentration by 3-fold and cGMP concentration by 20-fold and inhibited proliferation by 81%. Concentrations of 8-bromo cAMP, 8-bromo cGMP, forskolin or SIN-1 that inhibited proliferation did not affect the elevation of intracellular free Ca2+ concentration caused by 2% (v/v) foetal-bovine serum, 100 nM-5-hydroxytryptamine or 10 nM-angiotensin II. The results demonstrate that elevation of intracellular cAMP and cGMP concentrations both independently inhibit vascular smooth-muscle cell proliferation, but these effects on proliferation are not mediated by inhibition of Ca2+ mobilization.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001011:Aorta; D002118:Calcium / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects*; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology*; D006152:Cyclic GMP / Q000494:pharmacology*; D066298:In Vitro Techniques; D009130:Muscle, Smooth / Q000166:cytology* / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011817:Rabbits; D012701:Serotonin / Q000494:pharmacology
chemical_list: D010982:Platelet-Derived Growth Factor; D000804:Angiotensin II; D005576:Colforsin; D012701:Serotonin; D000242:Cyclic AMP; D006152:Cyclic GMP; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine