Butorphanol is a synthetic opioid analgesic medication that is primarily used for the management of pain. Butorphanol may have an inhibitory effect on androgen biosynthesis and metabolism in rat immature Leydig cells. The objective of this study was to investigate the influence of butorphanol on androgen secretion by rat Leydig cells isolated from the 35-day-old male rats. Rat Leydig cells were cultured with 0.5-50 μM butorphanol for 3 h in vitro. Butorphanol at 5 and 50 μM significantly inhibited androgen secretion in immature Leydig cells. At 50 μM, butorphanol also blocked the effects of luteinizing hormone (LH) and 8bromo-cAMP-stimulated androgen secretion and 22R-hydroxycholesterol- and pregnenolone-mediated androgen production. Further analysis of the results showed that butorphanol downregulated the expression of genes involved in androgen production, including Lhcgr (LH receptor), Cyp11a1 (cholesterol side-chain cleavage enzyme), Srd5a1 (5α-reductase 1), and Akr1c14 (3α-hydroxysteroid dehydrogenase). Additionally, butorphanol directly inhibited HSD3B1 (3β-hydroxysteroid dehydrogenase 1) and SRD5A1 activity. In conclusion, butorphanol may have side effects of inhibiting androgen biosynthesis and metabolism in Leydig cells.
Keywords: Leydig cells; androgen production; butorphanol; steroidogenic enzymes.