TY - JOUR
T1 - Endogenous Sex Hormones Modulate the Analgesic Effect of Tramadol in Lean and High-Fat Diet-Induced Obese Wistar Rats
T2 - A Preclinical Molecular Approach
AU - Satyam, Shakta Mani
AU - Bairy, Laxminarayana Kurady
AU - Shetty, Prakashchandra
N1 - Publisher Copyright:
© 2023 Journal of International Humanitarian Legal Studies. All rights reserved.
PY - 2023/5/1
Y1 - 2023/5/1
N2 - INTRODUCTION: Differences in pain thresholds may have implications in pain management, as they may account in part for the variability in analgesic requirements between individuals. We planned to investigate the influence of endogenous sex hormones on the analgesic modulation of tramadol in lean and high-fat diet-induced obese Wistar rats. METHODS: The whole study was carried out on 48 adult Wistar rats (24 male: 12 obese and 12 lean and 24 female: 12 obese and 12 lean). Each male and female rat group was further subdivided into two groups (n = 6/group) and treated with normal saline/tramadol for 5 days. On the fifth day, 15 min after tramadol/normal saline treatment, animals were tested for pain perception toward noxious stimuli. Later, endogenous 17 beta-estradiol and free testosterone levels in serum were estimated through ELISA methods. RESULTS: The present study revealed that female rats experienced more pain sensitivity to noxious stimuli compared to male rats. High-fat diet-induced obese rats experienced more pain sensations to noxious stimuli than lean rats. Obese male rats were found to have significantly low free testosterone and high 17 beta-estradiol levels compared to lean male rats. An increase in serum 17 beta-estradiol level led to increased pain sensation to noxious stimuli. While an increase in free testosterone level resulted in the lowering of pain sensation to noxious stimuli. CONCLUSION: The analgesic effect of tramadol was more pronounced in male rats compared to female rats. The analgesic effect of tramadol was more marked in lean rats compared to obese rats. Additional research to elucidate obesity-induced endocrine changes and the mechanisms driving sex hormones in pain perception is needed to foster future interventions to reduce disparities in pain.
AB - INTRODUCTION: Differences in pain thresholds may have implications in pain management, as they may account in part for the variability in analgesic requirements between individuals. We planned to investigate the influence of endogenous sex hormones on the analgesic modulation of tramadol in lean and high-fat diet-induced obese Wistar rats. METHODS: The whole study was carried out on 48 adult Wistar rats (24 male: 12 obese and 12 lean and 24 female: 12 obese and 12 lean). Each male and female rat group was further subdivided into two groups (n = 6/group) and treated with normal saline/tramadol for 5 days. On the fifth day, 15 min after tramadol/normal saline treatment, animals were tested for pain perception toward noxious stimuli. Later, endogenous 17 beta-estradiol and free testosterone levels in serum were estimated through ELISA methods. RESULTS: The present study revealed that female rats experienced more pain sensitivity to noxious stimuli compared to male rats. High-fat diet-induced obese rats experienced more pain sensations to noxious stimuli than lean rats. Obese male rats were found to have significantly low free testosterone and high 17 beta-estradiol levels compared to lean male rats. An increase in serum 17 beta-estradiol level led to increased pain sensation to noxious stimuli. While an increase in free testosterone level resulted in the lowering of pain sensation to noxious stimuli. CONCLUSION: The analgesic effect of tramadol was more pronounced in male rats compared to female rats. The analgesic effect of tramadol was more marked in lean rats compared to obese rats. Additional research to elucidate obesity-induced endocrine changes and the mechanisms driving sex hormones in pain perception is needed to foster future interventions to reduce disparities in pain.
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U2 - 10.1159/000529761
DO - 10.1159/000529761
M3 - Article
C2 - 36796342
AN - SCOPUS:85160968725
SN - 0028-3835
VL - 113
SP - 667
EP - 677
JO - Neuroendocrinology
JF - Neuroendocrinology
IS - 6
ER -