The Action of Ergometrinine

Abstract

Ergometrinine is one of the newer alkaloids of ergot isolated by Smith and Timmis. 1 It decomposes at about 195° and has an optical rotation of [α]²⁰ ₅₄₆₁ + 598°. Its empirical formula is the same as that for ergometrine, that is, C₁₉H₂₃O₂N₂. Raymond-Hamet 2 reported that in the dog ergometrinine caused a rise of blood pressure and vasoconstriction, and that with a dose of 24.5 mg. per kg., it abolished the vasoconstricting action of adrenalin. He concluded that ergometrinine was weaker than ergometrine.

With the aid of Mr. Howard B. Fonda, Experimental Research Laboratories, Burroughs Wellcome and Company, Tuckahoe, we were able to secure 50 mg. of ergometrinine nitrate. The material is easily soluble in water and exhibits a blue fluorescence in aqueous solution. Unlike ergotoxine or ergotamine, ergometrinine does not inhibit the adrenalin response on the isolated rabbit's uterus in a concentration as strong as 1:27,777 (the Broom-Clark test 3 ), but on the contrary, it exerts a weak stimulating action itself. When assayed by the method described previously, 4 ergometrinine HNO₃ was shown to be 1/100 as active as ergotocin maleate in 6 observations (Fig. 1A).