Steroids in Fluids and Sperm Entering and Leaving the Bovine Epididymis, Epididymal Tissue, and Accessory Sex Gland Secretions¹

Abstract

Ten steroids which may have a role in the process of sperm maturation within the epididymis were quantified by competitive protein binding or radioimmunoassay. Rete testis fluid (RTF) carrying testicular sperm into the epididymis was rich in dehydroepiandrosterone and testosterone (21 +/- 2 and 33 +/- 3 ng/ml) while cauda eipididymal plasma (CEP) around sperm which have completed maturation had high levels of progesterone, dihydrotestosterone, 3beta-androstanediol, dehydroepiandrosterone and testosterone (7.4 +/- 0.8, 20.3 +/- 1.1, 6.5 +/- 0.4, 8.0 +/- 0.7 and 11.5 +/- 0.7 ng/ml). About 4 mug of steroids enter the epidymis daily in RTF, but less than 1% was found in CEP; the balance presumably was absorbed by the epithelium in the proximal caput epididymidis. Nevertheless, tissue levels of total 17beta-OH androgens were lower in the proximal caput than in the distal caput or corpus epididymidis. In all zones of the epididymis, dihydrotestosterone accounted fro about 70% of the total 17beta-OH androgens found in the nuclear fraction. In the cytoplasmic fraction, however, dihydrotestosterone predominated only in the distal caput and corpus epididymidis. In the cauda epididymidis, CEP and sperm probably accounted for less than 35% of the total 17beta-OH androgens and less than 25% of the dihydrotesterone. The progesterone concentration of the cauda than in the caput epidymidis. Twice washed testicular sperm contained more testosterone than cauda epididymal or ejaculated sperm (16.6 +/- 1.9, 1.6 +/- 0.2 and 1.5 +/- 0.3 ng/10(9) sperm, respectively), but less progesterone (0.5 +/- 0.1, 1.3 +/- 0.2 and 1.0 +/- 0.4 ng/10(9) sperm, respectively). As a consequence of mixture with estrogen-rich prostatic fluid (150 +/- 9 pg/ml), ejaculated sperm contained a relatively high amount of estrogens (112 +/- 15 pg/10(9) sperm). These studies revealed marked differences in steroid profiles of fluids entering and leaving the epididymis and of infertile testicular and fertile cauda epididymal sperm.

Immunolocalization and Regulation of Cystatin 12 in Mouse Testis and Epididymis1

“…Estrogen is one of the testicular factors that is present at high concentration in rete testis fluid [41,49]. It has been established that estrogen receptors are present in the caput epididymis of mice [50], and estrogen plays an important role in the regulation of epididymal function [51,52].…”

Cystatin E1 and E2, New Members of Male Reproductive Tract Subgroup Within Cystatin Type 2 Family1

“…In addition, no regionspecific regulation of mCST E1 or mCST E2 by androgen was detected by in situ hybridization. This indicates that the regulation pattern of mCST E1 and mCST E2 may be different from that of human genes, such as CST 11. In males, estrogen is present at a low concentration in the blood stream but can be extraordinarily high in semen and as high as 250 pg/ml in rete testis fluid [46,47], which is higher than the level of serum estradiol in the female [48]. Male reproductive tissues express ERs [49][50][51][52], and both the ␣ and ␤ forms of the ER are present in the caput epididymis of mice [30].…”

17β-estradiol signaling and regulation of Sertoli cell function

“…28,29 The role of estrogen in male reproduction had remained unclear until the first studies with mice with targeted disruption of ESRs (Esr1 -/-). 30,31 Esr1 -/-male is infertile, its testes appeared normal until puberty but began to degenerate afterwards and became atrophic at adult age, and they also presented abnormalities in spermatogenesis and sperm concentration.…”