Prostaglandin E1 modifies porcine cerebral arterial tone through cyclooxygenase related eicosanoid(s) release

The effects of prostaglandin E1 (PGE1) on porcine cerebral arteries were studied in the absence and presence of cyclooxygenase inhibitors, 5 x 10(-6) M indomethacin or 10(-4) M aspirin. In preparations placed at a resting tension, 3 x 10(-9) to 10(-6) M PGE1 caused dose-dependent contractions. In prostaglandin F2 alpha (PGF2 alpha)- contracted preparations, low concentrations of 10(-9) and 3 x 10(-9) M PGE1 did not modify arterial tone and higher concentrations of 10(-8) to 10(-6) M PGE1 further increased the arterial tone in all preparations tested. In contrast, in the presence of the cyclooxygenase inhibitors, low concentration of 10(-9) and 3 x 10(-9) M PGE1 markedly decreased the arterial tone induced by PGF2 alpha and higher dose of 10(-8) to 10(-6) M PGE1 increased the arterial tone in 15 of 18 preparations (83%). These findings suggest that PGE1 modifies porcine cerebral vascular tone at least partly through cyclooxygenase-related eicosanoid(s) production.