Abstract | BACKGROUND: METHODS:
Pain sensitivity was evaluated in rats by formalin test during all stages of estrous cycle. Animals were divided into five groups including; 1- control (intact animal); 2- sham 1 receiving 0.75 µl artificial cerebrospinal fluids (ACSF); 3- sham 2 receiving 0.75 µl alcoholic ACSF; 4- experimental 1 receiving 250 or 500 µg/rat of muscimol in 0.75 µl vehicle, and 5- experimental 2 receiving 20 or 30 µg/rat picrotoxin in 0.75 µl vehicle. Data were analyzed by Kruskal-Wallis followed by Tucky's test for pairwise comparisons using a P value of ≤0.50 for statistical significance. RESULTS:
Muscimol significantly (P<0.05) decreased pain sensitivity in all stages of estrous cycle, and the analgesic effect was higher during proestrus and estrus stages of estrous cycle than that during metestrus and diestrus stages. Picrotoxin significantly (P<0.05) increased pain sensitivity in all stages of estrous cycle, and such a hyperalgesic effect was lower during proestrus and estrus stages of estrous cycle than that during metestrus and diestrus stages. CONCLUSION: The findings of the present study indicate that the role of hippocampal GABA(A) receptor in the control of the pain sensitivity can be modulated by variation in gonadal steroids during different stages of the estrous cycle.
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Authors | Mahnaz Taherianfard, Mahnaz Mosavi |
Journal | Iranian journal of medical sciences
(Iran J Med Sci)
Vol. 36
Issue 4
Pg. 289-95
(Dec 2011)
ISSN: 1735-3688 [Electronic] Iran |
PMID | 23115414
(Publication Type: Journal Article)
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