Biochemical Studies on Vasodilative Factor in Royal Jelly

It was found that the water-soluble fraction of royal jelly contained a factor which had a vasodilating activity on dog femoral artery. This activity was transitory, was present in 100- to 200-fold of that in honey, and the activity was rapidly lost in alkaline aqueous solution. This active factor was partially purified by Sephadex G-25 chromatography, and various examinations were made to elucidate its principle. It was thereby found that this factor was inactivated by the protease treatment, was antagonized by atropine, and was inactivated by the true cholinesterase. Consequently, this vasodilating factor was considered to be a cholinergic substance, and was determined as acetylcholine by paper chromatography.