Properties of human seminal plasma

Abstract

The pharmacological properties of human seminal plasma are described and a comparison is made between the substance (or substances) responsible for these properties and other pharmacologically active bodies. Human male semen was collected and purified and its effect on blood pressure isolated intestinal strips nonpregnant uterus (all in rabbits) isolated seminal vesicles of guinea pigs and eserinized rectus abdominis of frogs was tested by recording muscle response to injection of the seminal fluid. Results showed that human seminal plasma has a strong vasodilator which produces strong stimulation of plain muscle. This seminal substance could be distinguished from substances found in other tissue extracts having similar vasodilator activities. Threfore it is suggested that the vasodilator may help maintain local vasodilatation in accessory glands and ducts of the male genital tract and ensure an active gaseous exchange between the blood and various seminal secretions. Also postulated is that the oxytocic power of seminal plasma is caused by a substance distinct from this depressor. The seminal oxytocic substance has a histamine equivalent of from .4-.6 mg per cu. cm. The effect of this seminal plasma substance on the eserinized rectus abdominis of frogs was similar to acetylcholine.