Progesterone in vitro increases NMDA-evoked [3H] dopamine release from striatal slices in proestrus rats.
The dopaminergic nerve terminals in rat striatum appear to be an important target for progesterone (Pg) and the excitatory amino acid glutamate. In the present study the possible interaction between glutamate and Pg upon [3H]DA release in striatal slices from rats in proestrus was examined. [3H]DA release was augmented by NMDA in a concentration-dependent manner. The presence of Pg (400 nM) in the perfusion medium produced an amplification of the responses to NMDA (50 microM) as shown by significant increase in the tritium outflow. The NMDA selective antagonists AP-7 (100 microM) and MK-801 (0.1 microM) prevented the effects of both NMDA and NMDA plus Pg on [3H]DA release. In contrast, the AMPA/kainate receptor antagonist CNQX (10 and 20 microM) was ineffective. Furthermore, AP-7 (100 microM) attenuated the enhancing effect of 400 nM Pg on [3H]DA release evoked by 28 mM K+. The antagonist was unable to alter the effect produced by K+ alone. These results indicate a specific action of Pg on dopaminergic terminals mediated by NMDA receptors and suggest a close interaction between glutamate and dopamine systems in the striatum, apparently modulated by progesterone.
Cabrera
R J
RJ
Laboratorio de Investigaciones Cerebrales, LINCE-CONICET; Facultad de Ciencias Medicas, UNCuyo, Mendoza, Argentina.
Navarro
C E
CE
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004357:Drug Synergism; D004971:Estrus; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D016202:N-Methylaspartate / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014316:Tritium
D000927:Anticonvulsants; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D014316:Tritium; D011374:Progesterone; D016202:N-Methylaspartate; D016291:Dizocilpine Maleate; D015763:2-Amino-5-phosphonovalerate; C031231:2-amino-7-phosphonoheptanoic acid; D004298:Dopamine