Dilator Prostanoid-induced Cyclic AMP Formation and Release by Cerebral Microvascular Smooth Muscle Cells: Inhibition by 1

The effect of indomethacin on dilator prostanoid receptor-me-diated cAMP formation was investigated using primary cultures of vascular smooth muscle cells from the newborn pig cerebral microvessels. Cerebral microvascular smooth muscle cells re-sponded to dilator prostanoids (iloprost> PGE) by increasin cAMP formation and release into the media (EC = 2 x 10 M and 2 x 1 O- M for iloprost and PGE2, respectively). Indo-methacin inhibited iloprost- and PGE2-evoked increases in cAMP formation (lC = iO M) and release (lC = 10_6 M) by microvascular smooth muscle cells (maximal inhibition 80-90%), whereas isoproterenol-induced CAMP formation was only slightly attenuated at the highest concentration of indo-methacin used (1 0 M). Aspirin was much less effective in inhibiting dilator prostanoid-induced cAMP formation and re