FEVRE, M., JORDAN, I?., TOURN~AIRE, J., and MORNEX, R. 1979. eotnparison of pharrnacological erect of adiphenine and physiological stim~llation by luteinizing hormone releasing hormone on lbnteinizing hormone release by rat anterior pituitaries in vitro. Can. J. Physiol. Pharmacol. 57, 1388-1392 The mechanism of action of adiphenine on ĩm vitro rat anterior pituitary LH release was studied and compared with that of the physiological stimulator luteiniring hormone releasing hormone (LH-KM) on LH release. The comparative study showed that adipheniale and LH-RM were able to increase medium LH concentration in a dose-dependent manner and had similar time courses of action between I and 4 h incubation. However, there were several main differences between the effects of adipheiline and LM-WH. The adiphenine: action was not calcium dependent, was inhibited in a high K+ medium concentration, and was substituted after energy depression. It is concluded that adipheninse probably acts near the ultimate steps of the LH release pathway and could be a useful pharniacological tool for studying the mechanism of LH release. FEVRE, M., JORDAN, D., TOUWNIAIRE, J., et MORNEX, W. 1979. Comparison s f pharmacological efTect of adiphenine and physiological stitnulation by luteiniaing hormone releasing hormone on luteiniring hormone release by rat anterior pituitaries in vitro. Can. J. Physiol. Pharmacol. 57, 1388-1392. On a 6tudiC i~t vitro c h e~ Ie rat, le mecanisme d9action de l'adiphgnine sur la liberation de LH par l'hypophyse antericurc. Ceci a it& compare au m6canrsme du stirnulatetar physiologique LH-RH de la libkation de LH. Cette Ctude comparative a montr6 que I'adiphknine et LH-RH son% capakles d'augmenter la concentration du milieu en EH de faqon dose-dkpendante et yue ceci implique des durCes d'action conaparables avec une incubation de 1 A 4 k. I1 existe cependant pluslieurs differences importantes entre les effets de i'adiphktaine et ccux de LH-RM. L9action de l'adinephine n9est pas calcium-dependante, est inhibke par Len milieu riche en Kt et est remplacie suite h une diminution en Cnergie. On conclut que l'adinCphine agit probablement pr$s de 15extr6mitC dia trajet de lilkration ale L H et pourrallt constituer un outil pharmacologique pratique dans 15itude du ~~Pcanisme de la libbation de LH. [Tradmit par le journal]
IntoduetionIt has been previously shown that adiphenine hydrochloride (%-diethylaminoethyl diphenylacetate hydrochloride), known for its atropinic properties, can also stirnralate the TSH release from rat anterior pituitaries in viero in a dose-related manner from 0.5 to 4 mM (Mornex et al. 1973;Jordan et al. 1977) without histological evidence of necrosis or nnembrane alteration of anterior pituitary cells. The possibility of a plurality of action of this drug at adenolaypofiysis level led us to test the action of adiphenine on other anterior pituitary gly coprotein A~13ar.va.4~1o~s: LH-RH, luteinizing hornlone releasing hormone; KRBgBu, Krebs-Ringer bicarbonate rnediuwa with glucose (0.01 M ) ; 2,4-DNP,...