The effect of calcium ions on testosterone production in Leydig cells from rat testis

• Published in: Biochemical journal 1976-12, Vol.160 (3), p.433-437
• Main Authors: Janszen, F H, Cooke, B A, Van Driel, M J, Van Der Molen, H J
• Format: Article
• Language: English
• Subjects: Animals; Calcium - pharmacology; Enzyme Activation; In Vitro Techniques; Leydig Cells - enzymology; Leydig Cells - metabolism; Luteinizing Hormone - pharmacology; Male; Protein Kinases - metabolism; Rats; Stimulation, Chemical; Testosterone - biosynthesis
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/bj1600433

Leydig-cell suspensions, prepared from rat testes, were incubated with different amounts of Ca2+ with and without added luteinizing hormone. The basal testosterone production in the absence of luteinizing hormone was unaffected by the Ca2+ concentration in the incubation medium. The luteinizing hormone-stimulated testosterone production, however, was progressively decreased in the absence of Ca2+ to one-third of that with 2.50 mM-Ca2+. This decrease in luteinizing hormone-stimulated testosterone production was independent of the different concentrations of luteinizing hormone (0-10mug/ml) used and could be restored by the addition of Ca2+ to the incubation medium. The restoration of the stimulation was achieved within 30 min after the addition of Ca2+ to the medium. Activation of cyclic AMP-dependent protein kinase by luteinizing hormone was not decreased by omission of Ca2+ from the incubation medium, suggesting that Ca2+ may be involved in steroidogenesis at a stage beyond the luteinizing hormone receptor-adenylate cyclase-protein kinase system.