Cardiovascular research
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Cardiovascular research · Sep 1996
Inhibition of beta- but not alpha 1-mediated adrenergic responses in isolated hearts and cardiomyocytes by nitric oxide and 8-bromo cyclic GMP.
The study was carried out to assess the effect of nitric oxide (NO) generation or inhibition of NO synthase on the cardiac response to beta- and alpha 1-adrenergic agonists. In addition, we determined the effects of the cell-permable analogue of cGMP, 8-bromo-cGMP (8Br-cGMP). ⋯ The present study demonstrate that NO as well as guanylate cyclase inhibitors and, to a lesser extent, 8Br-cGMP attenuate beta-receptor-mediated cardiac responses and supports the concept that NO serves as an endogenous regulator of beta-mediated effects of catecholamines in the heart. In addition, our findings suggest that the antiadrenergic effects of NO are restricted to these receptors but likely do not involve alpha 1-mediated effects.