| Registro completo |
| Provedor de dados: |
BJMBR
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| País: |
Brazil
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| Título: |
Prazosin blocks the glutamatergic effects of N-methyl-D-aspartic acid on lordosis behavior and luteinizing hormone secretion in the estrogen-primed female rat
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| Autores: |
Landa,A.I.
Cabrera,R.J.
Gargiulo,P.A.
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| Data: |
2006-03-01
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| Ano: |
2006
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| Palavras-chave: |
Sexual behavior
Glutamate
Luteinizing hormone
Noradrenergic transmission
Prazosin
N-methyl-D-aspartic acid
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| Resumo: |
We have observed that intracerebroventricular (icv) injection of selective N-methyl-D-aspartic acid (NMDA)-type glutamatergic receptor antagonists inhibits lordosis in ovariectomized (OVX), estrogen-primed rats receiving progesterone or luteinizing hormone-releasing hormone (LHRH). When NMDA was injected into OVX estrogen-primed rats, it induced a significant increase in lordosis. The interaction between LHRH and glutamate was previously explored by us and another groups. The noradrenergic systems have a functional role in the regulation of LHRH release. The purpose of the present study was to explore the interaction between glutamatergic and noradrenergic transmission. The action of prazosin, an alpha1- and alpha2b-noradrenergic antagonist, was studied here by injecting it icv (1.75 and 3.5 µg/6 µL) prior to NMDA administration (1 µg/2 µL) in OVX estrogen-primed Sprague-Dawley rats (240-270 g). Rats manually restrained were injected over a period of 2 min, and tested 1.5 h later. The enhancing effect induced by NMDA on the lordosis/mount ratio at high doses (67.06 ± 3.28, N = 28) when compared to saline controls (6 and 2 µL, 16.59 ± 3.20, N = 27) was abolished by prazosin administration (17.04 ± 5.52, N = 17, and 9.33 ± 3.21, N = 20, P < 0.001 for both doses). Plasma LH levels decreased significantly only with the higher dose of prazosin (1.99 ± 0.24 ng/mL, N = 18, compared to saline-NMDA effect, 5.96 ± 2.01 ng/mL, N = 13, P < 0.05). Behavioral effects seem to be more sensitive to the alpha-blockade than hormonal effects. These findings strongly suggest that the facilitatory effects of NMDA on both lordosis and LH secretion in this model are mediated by alpha-noradrenergic transmission.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000300007
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| Editor: |
Associação Brasileira de Divulgação Científica
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| Relação: |
10.1590/S0100-879X2006000300007
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Medical and Biological Research v.39 n.3 2006
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| Direitos: |
info:eu-repo/semantics/openAccess
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