Alteration of vein cyclic 3':5' nucleotide concentrations during changes in contractility

The relative changes in vascular tissue levels of cyclic 3':5'-guanosine monophosphate (cGMP) and cyclic 3':5'-adenosine monophosphate (cAMP) were determined in bovine and canine vein strips that were quickfrozen during changes in contractility elicited by prostaglandins (PG) or isoproterenol. Prostaglandin F(2alpha)-induced venoconstriction was associated with increased vascular tissue levels of cGMP and increased ratios of cGMP to cAMP concentrations, but no consistent qualitative change in cAMP levels. In contrast, vein cAMP concentrations were increased during administration of the vasodilators PGE(2) and isoproterenol. The results suggest possible opposing roles for the two cyclic nucleotides in vasomotion.