Evaluation of relative roles of LH and FSH in regulation of differentiation of Leydig cells using an ethane 1,2-dimethylsulfonate-treated adult rat model

Abstract

The relative role of LH and FSH in regulation of differentiation of Leydig cells was assessed using an ethane 1,2-dimethylsulfonate (EDS)-treated rat model in which endogenous LH or FSH was neutralized from day 3 to day 22 following EDS treatment. Serum testosterone and the in vitro response of the purified Leydig cells to human chorionic gonadotropin (hCG) was monitored. In addition RNA was isolated from the Leydig cells to monitor the steady-state mRNA levels by RT-PCR for 17 -hydroxylase, side chain cleavage enzyme, steroidogenic acute regulatory protein (StAR), LH receptor, estrogen receptor (ER-) and cyclophilin (internal control). Serum testosterone was undetected and the isolated Leydig cells secreted negligible amount of testosterone on stimulation with hCG in the group of rats that were treated with LH antiserum following EDS treatment. RT-PCR analysis revealed the absence of message for cholesterol side chain cleavage enzyme and 17 -hydroxylase although ERand LH receptor mRNA could be detected, indicating the presence of undifferentiated precursor Leydig cells. In contrast, the effects following deprival of endogenous FSH were not as drastic as seen following LH neutralization. Deprival of endogenous FSH in EDS-treated rats led to a significant decrease in serum testosterone and in vitro response to hCG by the Leydig cells. Also, there was a significant decrease in the steady-state mRNA levels of 17 -hydroxylase, cholesterol side chain cleavage enzyme, LH receptor and StAR as assessed by a semiquantitative RT-PCR. These results establish that while LH is obligatory for the functional differentiation of Leydig cells, repopulation of precursor Leydig cells is independent of LH, and also unequivocally establish an important role for FSH in regulation of Leydig cell function.

Infertility with defective spermatogenesis and steroidogenesis in male mice lacking androgen receptor in Leydig cells

“…Leydig AR is essential for production of testosterone T is the principal steroid produced and secreted by the testis, although numerous other C18, C19, and C21 steroids AR +/y 6.5 ± 1.0 7.5 ± 0.5 8.0 ± 0.5 + 2.56 · 10 7 /ml 72 L-AR -/y 0 0 0 + 0 0 T-AR -/y 0 0 0 -N oepididymis -are also produced [22][23][24]. In L-AR -/y mice the higher LH serum levels and LHR mRNA levels, subsequently induce expression of P450scc and StAR.…”

Identification of Intracisternal A-Particle Like Element as an FSH Regulated Transcript in Immature Rat Sertoli Cells

“…FSH action is important for the regulation of aromatase and the synthesis of estrogen in the Sertoli cell. Studies from our laboratory have demonstrated that the levels of estradiol, and aromatase decrease following neutralization of endogenous FSH [39]. It is also known that estrogen synthesis by Sertoli cells ceases by day 18 postnatally at which time proliferative response of the Sertoli cells to FSH also ceases.…”

Cell‐specific ablation in the testis: what have we learned?

“…The role of gonadotrophins in Leydig cell regeneration was established in early EDS studies using hypophysectomised rats or testosterone implants. This work showed that Leydig cell regeneration after EDS is dependent on LH (Molenaar et al ., 1986; Sriraman et al ., 2003) although some early proliferation and differentiation appears to occur independent of LH (Teerds et al ., 1989). Subsequent studies have shown that similar control mechanisms regulate normal adult Leydig cell development at puberty (Clark et al ., 2000; Gnessi et al ., 2000; Baker & O'Shaughnessy, 2001; Zhang et al ., 2001, 2004; Baker et al ., 2003).…”