8‐Bromoguanosine 3′:5′‐cyclic monophosphate decreases intracellular free calcium concentrations in cultured vascular smooth muscle cells from rat aorta

Open Access
Publisher Website
Google Scholar
Abstract
The effects of 8‐bromoguanosine 3′:5′‐cyclic monophosphate (8‐Br cGMP) on intracellular free calcium concentrations ([Ca2+]i) in cultured rat aortic vascular smooth muscle cells (VSMCs) loaded with fura‐2 were recorded microfluorometrically. Irrespective of whether VSMCs were at rest (in 5 mM K+ PSS), under Ca2+ depletion (in Ca2+‐free medium for 10 min) and K+ depolarization (in high K+ PSS), [Ca2+]i was actively reduced and reached a new and lower steady‐state level with the application of 8‐Br cGMP. This may be the first and direct evidence that cGMP, a putative mediator of various vasodilators, actively reduces [Ca2+]i in VSMCs.