LH contamination may explain FSH effects on rat Leydig cells

Area of Science:

• Reproductive Endocrinology
• Andrology
• Hormone Action

Background:

• Follicle-stimulating hormone (FSH) plays a role in testicular function.
• Leydig cells produce androgens, while Sertoli cells support spermatogenesis.
• The precise role of FSH in Leydig cell function is debated, potentially influenced by contaminants.

Purpose of the Study:

• To investigate the direct stimulatory effect of FSH on Leydig cells in immature, hypophysectomized male rats.
• To determine if LH contamination in FSH preparations contributes to observed Leydig cell stimulation.
• To compare the effects of different FSH preparations on Leydig and Sertoli cell function.

Main Methods:

• Immature, hypophysectomized male rats were treated with ovine FSH (NIH-FSH-S12).
• Leydig cells were isolated to measure 17 beta-hydroxyandrogen production in response to hCG.
• FSH preparations were pretreated with LH antiserum to assess the role of LH contamination.
• Another FSH preparation (LER-1881) was used for comparison.
• In vitro studies assessed steroid secretion from normal Leydig cells.

Main Results:

• FSH treatment (NIH-FSH-S12) stimulated maximum 17 beta-hydroxyandrogen production by Leydig cells in response to hCG.
• LH antiserum pretreatment reduced or abolished FSH's stimulatory effect on Leydig cells.
• FSH's effect on Sertoli cells (epididymal androgen-binding protein) was only slightly impaired by LH antiserum.
• LER-1881 showed no effect on Leydig cell dose-response but was superior for Sertoli cell stimulation.
• In vitro, Leydig cell stimulation correlated with LH contamination in hormone preparations.
• FSH treatment did not alter specific LH binding per Leydig cell.

Conclusions:

• The stimulatory effect of FSH on rat Leydig cells may be partly attributed to LH contamination.
• LH contamination appears to enhance Leydig cell responsiveness to hCG.
• Sertoli cell function is less affected by LH contamination compared to Leydig cell function.