THE EFFECTS OF PROSTAGLANDINS E1, E2 AND F2α ON THE CUTANEOUS VASCULATURE OF THE RAT

Abstract

1 The responses of the rat cutaneous vasculature to prostaglandins E₁, E₂ and F_2α have been investigated by a photomicrographic technique. 2 Prostaglandin E₁ produced transient arterial constriction which was blocked by local pretreatment of preparations with compound 48/80 or methysergide. It was concluded that prostaglandin E₁ produced vasoconstriction by release of 5-hydroxytryptamine (5-HT) from mast cells. The magnitude of the vasoconstrictor response appeared to be subject to seasonal variation. 3 Prostaglandin F_2α produced arterial constriction of longer duration which was not blocked by compound 48/80, methysergide or phenoxybenzamine. 4 Preparations pretreated with prostaglandin F_2α were found to be more sensitive to the venous constrictor effect, and less sensitive to the arterial constrictor effect, of noradrenaline. 5 Prostaglandin E₂ produced arterial constriction which was usually partially blocked by compound 48/80 and methysergide and it was concluded that a major component of the vasoconstrictor response to prostaglandin E₂ was of the E₁ type but some component was of the F_2α type.