title: Connexins and steroidogenesis in mouse Leydig cells.
abstract: Connexin43 has been recognized as forming gap junctions in Leydig cells. However, previous work has shown that mouse Leydig cells lacking this connexin do not suffer any limitation of their ability to produce testosterone when stimulated with luteinizing hormone. The objective of this study was to identify additional connexins in mouse Leydig cells that could be required for steroidogenesis. A reverse transcription - polymerase chain reaction screen involving isolated adult Leydig cells identified connexin36 and connexin45 as expressed along with connexin43. Treatment of dissociated testes with carbenoxolone, a nonspecific blocker of gap junctional coupling, significantly reduced testosterone output as did treatment with quinine, which disrupts coupling provided by connexin36 and connexin45 gap junctions but not those composed of connexin43, indicating that either or both of connexins 36 and 45 could be involved in supporting Leydig cell steroidogenesis. Immunolabeling of adult mouse testis sections confirmed the localization of connexin36 along with connexin43 in Leydig cell gap junctions but not connexin45, which is distributed throughout the cells. It was concluded that connexin36, connexin43, and connexin45 are coexpressed in Leydig cells with connexins 36 and 43 contributing to gap junctions. The role of connexin45 remains to be elucidated.
authors: Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada.
authors: Dan
authors: D
authors: Li
authors: Poonampreet
authors: P
authors: Sekhon
authors: Kevin J
authors: KJ
authors: Barr
authors: Lucrecia
authors: L
authors: Márquez-Rosado
authors: Paul D
authors: PD
authors: Lampe
authors: Gerald M
authors: GM
authors: Kidder
mesh_terms: D000818:Animals; D002229:Carbenoxolone / Q000494:pharmacology; D002478:Cells, Cultured; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism*; D017630:Connexins / Q000235:genetics / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D017629:Gap Junctions / Q000378:metabolism; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000494:pharmacology; D008297:Male; D051379:Mice; D011803:Quinine / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013737:Testis / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013739:Testosterone / Q000096:biosynthesis*; D000097004:Gap Junction delta-2 Protein
chemical_list: D002229:Carbenoxolone; D018031:Connexin 43; D017630:Connexins; D007986:Luteinizing Hormone; D011803:Quinine; D013739:Testosterone; D000097004:Gap Junction delta-2 Protein; C082920:connexin 45