Inhibition by N-methyl-D-aspartic acid (NMDA) receptor antagonist of lordosis behavior induced by estrogen followed by progesterone or luteinizing hormone-releasing hormone (LHRH) in the rat.
The effects of glutamate receptor antagonists on sexual receptivity induced by progesterone and LHRH were examined in ovariectomized, estradiol-primed rats (OVX-EB). Enhancement of lordosis/mounts quotient (L/M) by progesterone (0.5 mg) or LH-RH (150 ng; third ventricle, IVT) in OVX-EB rats was significantly decreased by IVT injection of (+) 2-amino-7-phosphonoheptanoic acid a competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist. On the contrary, there were no changes in L/M quotient after IVT injection of 6,7-dinitroquinoxaline-2,3,dione at two dose levels, a Non-NMDA receptor antagonist. The NMDA antagonist did not modify lordosis behavior in OVX-EB rats. The results indicate that the NMDA type of glutamate receptors appears to mediate progesterone and LHRH facilitatory actions and suggest that glutamatergic synapses may be involved in lordosis-facilitating neural mechanisms.
Gargiulo
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PA
Laboratorio de Investigaciones Cerebrales (LINCE), Facultad de Ciencias Médicas, U.N.C. Mendoza, Argentina.
Muñoz
V
V
Donoso
A O
AO
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives*; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D011374:Progesterone / Q000494:pharmacology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects* / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000187:drug effects* / Q000502:physiology
D000596:Amino Acids; D000927:Anticonvulsants; D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; C056723:FG 9041; D015763:2-Amino-5-phosphonovalerate; C010452:estradiol-17 beta-benzoate; C031231:2-amino-7-phosphonoheptanoic acid