Characterization of changes of pain behavior and signal transduction system in food-deprived mice |
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Authors: | Sang-Pil Jang Seong-Hwan Park Jun-Sub Jung Hee-Jung Lee Jung-Woo Hong Jae-Yong Lee |
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Affiliation: | 1. Department of Pharmacology, Institute of Natural Medicine, College of Medicine, Hallym University, Chuncheon, Korea;2. Department of Life science, Hallym University, Chuncheon, Korea;3. Department of Biomedical Science, Hallym University, Chuncheon, Korea;4. Department of Biochemistry, College of Medicine, Hallym University, Chuncheon, Korea |
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Abstract: | Fasting in general causes several metabolic changes. In the present study, we examined the possible changes of several types of nociception during the food deprivation were investigated in mice. After the mice were forced into the fasting for 12, 24, or 48?h, the changes of nociception were measured by the tail-flick, writhing, formalin or von-frey tests. We found that the nociceptive behavior induced by intraperitoneally (i.p.) administered acetic acid (writhing response) or intraplantar injection of 5% formalin into the hind-paw were reduced in fasted group. In addition, the tail-flick response and threshold for nociception in mechanical von-frey test were also elevated in fasted group. Moreover, the p-CREB and p-ERK levels in the dorsal root ganglia (DRG) and the spinal cord were reduced in food-deprived group. Furthermore, p-AMPKα1 expressions in DRG and the spinal cord were up-regulated, whereas p-mTOR in DRG and the spinal cord was down-regulated in food-deprived group. Our results suggest that the chemical, mechanical, and thermal nociceptions appear to be reduced in a food-deprived mouse group. Additionally, reduction of nociception in food-deprived group appears to be closely associated with the expressions of several signal transduction molecules such as ERK, CREB, AMPKα1 and mTOR proteins in DRG and the spinal cord. |
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Keywords: | Nociception pain food deprivation signal transduction dorsal root ganglia |
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