Beta-adrenergic stimulation inhibits calcium efflux and alters the morphology of cultured arterial muscle cells.
Beta-adrenoreceptor stimulation with isoproterenol (IP) rapidly and reversibly rounded and arborized smooth muscle cells (SMC) cultured from rat aorta. The arborized SMC remained firmly attached to the substratum via a network of long, dendritelike processes. Arborization of the SMC correlated closely with increases in cellular cAMP produced by IP and a variety of other compounds. The intracellular calcium antagonist 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate (TMB-8) also rounded and arborized the SMC. Antitubulin compounds potently blocked arborized by IP, dibutyryl cAMP, and TMB-8. The release of cell-bound 45Ca2+ was followed in the presence and absence of IP. IP strikingly increased the amount of 45Ca2+ that remained cell bound between 20 and 120 min. Propranolol and colchicine prevented IP from inhibiting the release of cell-bound 45Ca2+. These results suggest that the modulation of Ca2+ transport is involved in the arborization of cultured SMC by cAMP.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D015638:Cytochalasin D; D003572:Cytochalasins / Q000494:pharmacology; D007424:Intracellular Fluid / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*
D003572:Cytochalasins; D011943:Receptors, Adrenergic, beta; D015638:Cytochalasin D; D011433:Propranolol; D000242:Cyclic AMP; D007545:Isoproterenol; D015056:1-Methyl-3-isobutylxanthine