Constriction of Pial Arterioles Produced by Prostaglandin F 2α

Abstract

Prostaglandin F_2α constricted pial arterioles when locally applied to the cerebral surface. Norepinephrine and serotonin each elicited similar contractile effects. The constriction produced by F_2α in combination with either biogenic amine was greater than the constriction elicited by F_2α or amine acting alone. The effect of one agent on the other was additive rather than potentiating. Since F_2α, norepinephrine and serotonin are all naturally occurring agents, it is possible that their combined effect is important under pathological circumstances and this combined effect should not be overlooked in the search for single spasmogens of great potency. Before ascribing a pathologically important effect to F_2α, either alone or in combination, evidence is required showing that doses effective in experiments are similar to the concentrations occurring during disease states and/or that vessels may become hypersensitive to F_2α during such states.