Inositol in seminal plasma

Abstract

Free and total inositol were assayed in seminal plasma, and in some accessory organs of the male reproductive tract, by a microbiological method which utilizes the yeast Kloeckera brevis. Boar seminal plasma contains 600-700 mg of inositol/100 ml, most of which is in the free state. Bull, human, rabbit, ram and stallion seminal plasma contain less than 100 mg/ml. In all species the inositol concentration is much greater than in blood and cerebrospinal fluid. It is suggested that the inositol content of boar semen can be taken as an index of the secretory activity of the seminal vesicles. A parallelism between the levels of fructose and inositol in body fluids supports the view that inositol may function as an intermediate in the interconversion of glucose and fructose, but at present there is no evidence for any metabolic role of inositol in semen.