Human Chorionic Gonadotropin β-Subunit in Human Semen

Abstract

The level of human seminal chorionic gonadotropin 0-subunit (hCGP) was determined by radioimmunoassay (RIA). The mean hCGP level in 34 normal men was 3.7 f 1.6 ngfml, which was much higher than that in serum. The mean hCG0 level for 20 patients with mild oligozoospermia (20-39 x lo6 sperm/ml) was 2.5 f 0.8 ng/ml, that for 34 patients with severe oligozoospermia (1-19 x lo6 sperm/ ml) was 1.7 f 0.5 ng/ml, and that for 21 azoospermia was 1.5 * 0.6 ng/ml. Thus, the decrease of sperm count was correlated with the decrease of hCGP. In 17 cases to which testicular biopsy was applied together with sperm counting, the seminal hCG0 level was found to positively correlate with the germinal cell index (the ratio germinal cell count/Sertoli cell count) and with the testicular volume. The level of seminal hCGP was also found to correlate negatively with the levels of seminal LH and FSH and positively with the Ipvel of seminal testosterone. These findings suggest that the production of seminal hCGP is a process of spermatogenesis and closely related to spermatogenesis. The level of hCGP in serum was too low to detect, and no relation to that in seminal plasma could be investigated. However, in 6 cases with testicular tumor, the hCGP level in serum was high, whereas that in seminal plasma was rather low probably because of unilateral secretion. Enhanced production of hCG0 by tumor tissues and the dp-truction of the blood-testis barrier by proliferation of tumor cells seemed to be one of the causes of this high hCGP level in serum. The hCG0 levels in 13 vasectomized seminal plasma and the prostatic fluid samples collected from 3 normal men were 1.5 ng/ml, which was similar to those in azoospermic patients. These findings suggest that the seminal hCGP level consists of the hCGP secreted by the testis and about 1.5 nglml of hCGP from the prostate. Based on these results, seminal hCGP is thought to be secreted by the prostate and the process of spermatogenesis and the value of seminal hCGP may serve as an effective index for the testicular function.

Occurrence and reproductive roles of hormones in seminal plasma

“…Alpha and beta subunits of human chorionic gonadotropin (hCG) have been studied in human seminal plasma over the past 30 years [ 41 , 53 , 54 ]. The levels of beta-hCG in seminal plasma were found to be higher than in the serum and to correlate with sperm parameters [ 53 , 54 ].…”

snaR Genes: Recent Descendants of Alu Involved in the Evolution of Chorionic Gonadotropins

“…Unlike other hCG␤ genes, hCG␤1/2 are expressed weakly in placenta but at relatively high levels in testis, to the extent that they account for approximately one-third of the total hCG␤ mRNA in this tissue (Rull et al 2008). Substantial concentrations of hCG␤ peptide have been detected in human semen and in fetal testis, where it is thought to act as the primary stimulus of fetal Leydig cells, resulting in early testosterone secretion and masculine differentiation of the male fetus (Clements et al 1976;Saito et al 1988;Brotherton 1989). Thus, hCG␤1/2 may have evolved to generate testicular hCG␤, functioning as a paracrine alternative to LHβ endocrine stimulation of Leydig cells.…”