Differences in the cyclic nucleotide mediation of luteinizing hormone-releasing hormone action on the rat and hamster anterior pituitary gland.
A continuous flow superfusion system which was previously developed in our laboratory was utilized to study the modulation of LH and FSH release by cyclic nucleotides and LHRH from anterior pituitary glands (APG) obtained from rats or hamsters. There was a transient increase in LH and FSH secretion from superfused rat APG in response to superfusion with 1 X 10(-3) M 1-methyl-3-isobutyl-xanthine (MIX), while 1 X 10(-4) MIX M had no effect. Furthermore, a dose of 5 X 10(-5) M MIX did not potentiate the gonadotrophin-releasing effect of 1 X 10(-10) M LHRH. Neither 1 X 10(-3) M 8-Br-cAMP nor 1 X 10(-3) M 8-Br-cGMP mimicked the gonadotrophin-releasing effects of 1 X 10(-9) M LHRH. In the experiments utilizing hamster APG, FSH release gradually increased during superfusion with 1 X 10(-3) M MIX or 1 X 10(-4) M MIX, while LH release was transient but significantly increased in response to superfusion with both doses of MIX. A dose of 5 X 10(-5) M MIX potentiated the effect of a low dose of LHRH (1 X 10(-10) M) upon both LH and FSH secretion. 1 X 10(-3) M 8-Br-cAMP mimicked the effect of LHRH upon LH and FSH released from superfused hamster APG, while 1 X 10(-3) M 8-Br-cGMP was inhibitory. These results suggest that cyclic nucleotides are involved in the mediation of the LHRH-induced release of gonadotropins from the anterior pituitary gland of the hamster, but do not mediate the LHRH-induced release of gonadotropins from the rat anterior pituitary gland.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology*; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D000818:Animals; D006224:Cricetinae; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D008647:Mesocricetus; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D013045:Species Specificity; D013806:Theophylline / Q000031:analogs & derivatives*
D015124:8-Bromo Cyclic Adenosine Monophosphate; C016276:8-bromocyclic GMP; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013806:Theophylline; D006152:Cyclic GMP; D015056:1-Methyl-3-isobutylxanthine