Vasopressor peptides and depolarization stimulated Ca 2+-entry into cultured vascular smooth muscle

• Published in: Biochemical and biophysical research communications Vol. 148; no. 1; pp. 225 - 231
• Main Authors: Zschauer, A., Scott-Burden, T., Bühler, F.R., van Breemen, C.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 14.10.1987
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/0006-291X(87)91099-0

45Ca-uptake was measured in monolayers of cultured rat aortic smooth muscle cells. Sufficient extracellular 45Ca could be removed by a 90 second cold La 3+ wash to reveal stimulation of 45Ca-uptake by high K +-depolarization and the vasopressor peptides angiotensin II and vasopressin. The high K +-stimulated 45Ca-influx was blocked by a dihydropyridine-type Ca 2+-antagonist while that stimulated by angiotensin II or vasopressin was not. The 45Ca-influx stimulated by high K + - depolarization was additive to that stimulated by angiotensin II. Vasopressin and angiotensin II stimulated 45Ca-fluxes were not additive. It is concluded that vasopressor peptides stimulate Ca 2+-entry through receptor operated Ca 2+-channels which are distinct from voltage gated Ca 2+-channels.