title: Extracellular calcium and luteinizing hormone effects on 22-hydroxycholesterol used for testosterone production in mouse Leydig cells.
abstract: The effect of extracellular calcium on testosterone synthesis in response to luteinizing hormone (LH) or 22-hydroxycholesterol (22-OH-C) by isolated adult mouse Leydig cells was studied. Leydig cells were isolated by linear density gradient centrifugation. The cells were incubated in minimum essential medium with or without calcium (1.36 mmol/L) in an atmosphere of 95% air and 5% carbon dioxide at 37 degrees C for 3 hours with or without LH (10 ng/sample), or with or without 22-OH-C (10 mumol/L). Testosterone production in response to LH was significantly lower (P less than 0.02) in the absence of extracellular calcium and in the presence of verapamil (10 mumol/L), a calcium channel blocking agent. Extracellular calcium did not significantly (P greater than 0.05) affect testosterone production in cells incubated with 22-OH-C in either the presence or absence of LH. The results suggest that steps in steroidogenesis from 22-OH-C to testosterone are unaffected by extracellular calcium content and that extracellular calcium affects the use of intracellular cholesterol by the cholesterol side-chain cleavage enzyme.
authors.affiliation: Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City 84132.
authors.forename: A W
authors.initials: AW
authors.lastname: Meikle
authors.forename: X H
authors.initials: XH
authors.lastname: Liu
authors.forename: J D
authors.initials: JD
authors.lastname: Stringham
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D006888:Hydroxycholesterols / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D007985:Leydig Cells / Q000187:drug effects* / Q000378:metabolism; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008297:Male; D051379:Mice; D013739:Testosterone / Q000096:biosynthesis*; D014700:Verapamil / Q000494:pharmacology
chemical_list: D006888:Hydroxycholesterols; C003585:22-hydroxycholesterol; D013739:Testosterone; D007986:Luteinizing Hormone; D014700:Verapamil; D002118:Calcium