19-Hydroxyprostaglandin E1 as a major component of the semen of primates

As their name implies, prostaglandins were first identified in secretions of the male reproductive tract. In the early 1930s several workers1–3 showed that human semen could stimulate various smooth muscle preparations, and this activity was ascribed to an unidentified component which von Euler named ‘prostaglandin’. von Euler4,5 then found that a watery alcoholic extract of rhesus monkey seminal vesicles markedly lowered the blood pressure in the rabbit but, unlike human seminal vesicle extracts, it had little or no action on the isolated intestine and the uterus of the rat and other laboratory animals. He therefore postulated the existence of another substance in the monkey which he named ‘vesiglandin’ and which he suggested could be a component of human seminal ‘prostaglandin’.