title: Nitric oxide and ERK/MAPK mediation of estrous behavior induced by GnRH, PGE2 and db-cAMP in rats.
abstract: We tested the hypothesis that GnRH, PGE2 and db-cAMP act via the nitric oxide (NO)-cGMP and MAPK pathways to facilitate estrous behavior (lordosis and proceptivity) in estradiol-primed female rats. Estradiol-primed rats received intracerebroventricular (icv) infusions of pharmacological antagonists of NO synthase (L-NAME), NO-dependent soluble guanylyl cyclase (ODQ), protein kinase G (KT5823), or the ERK1/2 inhibitor PD98059 15 min before icv administration of 50 ng of GnRH, 1 microg of PGE2 or 1 microg of db-cAMP. Icv infusions of GnRH, PGE2 and db-cAMP enhanced estrous behavior at 1 and 2 h after drug administration. Both L-NAME and ODQ blocked the estrous behavior induced by GnRH, PGE2 and db-cAMP at some of the times tested. The protein kinase G inhibitor KT5823 reduced PGE2 and db-cAMP facilitation of estrous behavior but did not affect the behavioral response to GnRH. In contrast, PD98059 blocked the estrous behavior induced by all three compounds. These data support the hypothesis that the NO-cGMP and ERK/MAPK pathways are involved in the lordosis and proceptive behaviors induced by GnRH, PGE2 and db-cAMP. However, cGMP mediation of GnRH-facilitated estrous behavior is independent of protein kinase G.
authors.affiliation: Centro de Investigación en Reproducción Animal, Universidad Autónoma de Tlaxcala-CINVESTAV, Apdo. Postal 62, Tlaxcala 90000, Mexico.
authors.forename: Oscar
authors.initials: O
authors.lastname: González-Flores
authors.forename: Porfirio
authors.initials: P
authors.lastname: Gómora-Arrati
authors.forename: Marcos
authors.initials: M
authors.lastname: Garcia-Juárez
authors.forename: Madaí A
authors.initials: MA
authors.lastname: Gómez-Camarillo
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Lima-Hernández
authors.forename: Carlos
authors.initials: C
authors.lastname: Beyer
authors.forename: Anne M
authors.initials: AM
authors.lastname: Etgen
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002227:Carbazoles / Q000494:pharmacology; D000242:Cyclic AMP / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015232:Dinoprostone / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D030762:Estrous Cycle / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005260:Female; D005419:Flavonoids / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors / Q000378:metabolism; D007276:Injections, Intraventricular; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015290:Second Messenger Systems / Q000187:drug effects / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D018709:Statistics, Nonparametric
chemical_list: D002227:Carbazoles; D004791:Enzyme Inhibitors; D005419:Flavonoids; C073601:KT 5823; D009569:Nitric Oxide; D007987:Gonadotropin-Releasing Hormone; D000242:Cyclic AMP; D048049:Extracellular Signal-Regulated MAP Kinases; D006162:Guanylate Cyclase; D015232:Dinoprostone; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D019331:NG-Nitroarginine Methyl Ester