[Subunits of lutropins: an intrinsic gonadotropic activity of alpha and the role of beta in the determination of the zoological specificity of action].
Pieces of Eel ovary were incubated in presence of various gonadotropic hormones or their subunits (alpha, beta) and cyclic adenosine monophosphate tissue concentration was measured. Carp gonadotropin (c-GTH) and a hybrid (bovine lutropin alpha-c-GTH beta) exhibited a very similar, intense, dose-dependent activity in the range 0.002-1 microgram/ml. Mammalian lutropins (LH) and their subunits became active in the range 1-100 microgram/ml: a strong stimulation (#30X) was attained with bovine LH alpha whereas the maximal stimulation obtained with bovine or ovine LH was #3X. This the activity of LH alpha cannot be due to a contamination by the hormone and it is intrinsic. The comparison of c-GTH, LH and hybrid actions indicate that the beta subunit plays a major role in determining the zoological specificity of action of the dimer.
D000811:Anguilla / Q000502:physiology*; D000818:Animals; D002347:Carps; D002417:Cattle; D000242:Cyclic AMP / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006062:Gonadotropins / Q000494:pharmacology; D007700:Kinetics; D007986:Luteinizing Hormone / Q000494:pharmacology*; D046911:Macromolecular Substances; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism; D012756:Sheep; D013045:Species Specificity
D006062:Gonadotropins; D046911:Macromolecular Substances; D007986:Luteinizing Hormone; D000242:Cyclic AMP
Les sous-unités des lutropines : une activité gonadotrope intrinsèque de alpha and et le rôle de beta dans le déterminisme de la spécificité zoologique d'action.