title: Low reversibility of intracellular cAMP accumulation in mouse Leydig tumor cells (MLTC-1) stimulated by human Luteinizing Hormone (hLH) and Chorionic Gonadotropin (hCG).
abstract: In order to study the intracellular cAMP response kinetics of Leydig cells to hormones with LH activity, we used MLTC-1 cells transiently expressing a chimeric cAMP-responsive luciferase so that real-time variations of intracellular cAMP concentration could be followed using oxiluciferin luminescence produced from catalyzed luciferin oxidation. The potencies of the different LHs and CGs were evaluated using areas under the curves (AUC) of their kinetics over 60 min stimulation. All mammalian LHs and CGs tested were found to stimulate cAMP accumulation in these cells. The reversibility of this stimulation was studied by removing the hormone from the culture medium after 10 min of incubation. The ratios of kinetics AUC after removing or not the hormone were used to evaluate the stimulation reversibility of each hormone. Natural and recombinant hLHs and hCGs were found to exhibit slowly reversible activation compared to pituitary rat, ovine, porcine, camel and equine LHs, serum-derived eCG (PMSG) and recombinant eLH/CGs. Carbohydrate side chains are not involved in this phenomenon since natural and recombinant homologous hormones exhibit the same reversibility rates. It is still unknown whether only one human subunit, α or β, is responsible for this behaviour or whether it is due to a particular feature of the hLH and hCG quaternary structure.
authors.affiliation: INRA, CNRS, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France.
authors.forename: Danièle
authors.initials: D
authors.lastname: Klett
authors.affiliation: INRA, CNRS, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France.
authors.forename: Philippine
authors.initials: P
authors.lastname: Meslin
authors.affiliation: INRA, CNRS, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France.
authors.forename: Lauriane
authors.initials: L
authors.lastname: Relav
authors.affiliation: INRA, CNRS, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France; Quy Nhon University, Viet Nam.
authors.forename: Thi Mong Diep
authors.initials: TM
authors.lastname: Nguyen
authors.affiliation: INRA, CNRS, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Mariot
authors.affiliation: INRA, CNRS, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France.
authors.forename: Gwenhaël
authors.initials: G
authors.lastname: Jégot
authors.affiliation: INRA, CNRS, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Cahoreau
authors.affiliation: INRA, CNRS, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly, France. Electronic address: combarno@tours.inra.fr.
authors.forename: Yves
authors.initials: Y
authors.lastname: Combarnous
mesh_terms: D000818:Animals; D019540:Area Under Curve; D002460:Cell Line; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism*; D006736:Horses; D006801:Humans; D007985:Leydig Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008297:Male; D051379:Mice; D051381:Rats; D011974:Receptors, LH / Q000378:metabolism; D012756:Sheep; D013552:Swine
chemical_list: D006063:Chorionic Gonadotropin; D011974:Receptors, LH; D007986:Luteinizing Hormone; D000242:Cyclic AMP
keywords: Adenylate cyclase; Chorionic gonadotropin (CG); Leydig cell; Luteinizing hormone (LH)