Melatonin reduces formalin-induced nociception and tactile allodynia in diabetic rats Export

@article{citeulike:4480560, abstract = {The purpose of this study was to assess the antinociceptive and antiallodynic effect of melatonin as well as its possible mechanism of action in diabetic rats. Streptozotocin (50 mg/kg) injection caused hyperglycemia within 1 week. Formalin-evoked flinching was increased in diabetic rats as compared to non-diabetic rats. Oral administration of melatonin (10–300 mg/kg) dose-dependently reduced flinching behavior in diabetic rats. In addition, K-185 (a melatonin MT 2 receptor antagonist, 0.2–2 mg/kg, s.c.) completely blocked the melatonin-induced antinociception in diabetic rats, whereas that naltrexone (a non-selective opioid receptor antagonist, 1 mg/kg, s.c.) and naltrindole (a selective δ opioid receptor antagonist, 0.5 mg/kg, s.c.), but not 5′-guanidinonaltrindole (a selective κ opioid receptor antagonist, 1 mg/kg, s.c.), partially reduced the antinociceptive effect of melatonin. Given alone K-185, naltrexone, naltrindole or 5′-guanidinonaltrindole did not modify formalin-induced nociception in diabetic rats. Four to 8 weeks after diabetes induction, tactile allodynia was observed in the streptozotocin-injected rats. On this condition, oral administration of melatonin (75–300 mg/kg) dose-dependently reduced tactile allodynia in diabetic rats. Both antinociceptive and antiallodynic effects were not related to motor changes as melatonin did not modify number of falls in the rotarod test. Results indicate that melatonin is able to reduce formalin-induced nociception and tactile allodynia in streptozotocin-injected rats. In addition, data suggest that melatonin MT 2 and δ opioid receptors may play an important role in these effects.}, author = {Arreolaespino, R. and Urquizamarin, H. and Ambriztututi, M. and Araizasaldana, C. and Caramsalas, N. and Rochagonzalez, H. and Mixcoatlzecuatl, T. and Granadossoto, V.}, citeulike-article-id = {4480560}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.ejphar.2007.09.006}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S0014299907010126}, day = {22}, doi = {10.1016/j.ejphar.2007.09.006}, issn = {00142999}, journal = {European Journal of Pharmacology}, keywords = {diabetes, formaldehyde, formalin, melatonin, nociception, tactile\_allodynia}, month = {December}, number = {1-3}, pages = {203--210}, posted-at = {2009-05-06 20:03:15}, priority = {3}, title = {Melatonin reduces formalin-induced nociception and tactile allodynia in diabetic rats}, url = {http://dx.doi.org/10.1016/j.ejphar.2007.09.006}, volume = {577}, year = {2007} }

TY - JOUR ID - citeulike:4480560 L3 - citeulike-article-id:4480560 N2 - The purpose of this study was to assess the antinociceptive and antiallodynic effect of melatonin as well as its possible mechanism of action in diabetic rats. Streptozotocin (50 mg/kg) injection caused hyperglycemia within 1 week. Formalin-evoked flinching was increased in diabetic rats as compared to non-diabetic rats. Oral administration of melatonin (10–300 mg/kg) dose-dependently reduced flinching behavior in diabetic rats. In addition, K-185 (a melatonin MT 2 receptor antagonist, 0.2–2 mg/kg, s.c.) completely blocked the melatonin-induced antinociception in diabetic rats, whereas that naltrexone (a non-selective opioid receptor antagonist, 1 mg/kg, s.c.) and naltrindole (a selective δ opioid receptor antagonist, 0.5 mg/kg, s.c.), but not 5′-guanidinonaltrindole (a selective κ opioid receptor antagonist, 1 mg/kg, s.c.), partially reduced the antinociceptive effect of melatonin. Given alone K-185, naltrexone, naltrindole or 5′-guanidinonaltrindole did not modify formalin-induced nociception in diabetic rats. Four to 8 weeks after diabetes induction, tactile allodynia was observed in the streptozotocin-injected rats. On this condition, oral administration of melatonin (75–300 mg/kg) dose-dependently reduced tactile allodynia in diabetic rats. Both antinociceptive and antiallodynic effects were not related to motor changes as melatonin did not modify number of falls in the rotarod test. Results indicate that melatonin is able to reduce formalin-induced nociception and tactile allodynia in streptozotocin-injected rats. In addition, data suggest that melatonin MT 2 and δ opioid receptors may play an important role in these effects. IS - 1-3 JF - European Journal of Pharmacology SN - 00142999 EP - 210 TI - Melatonin reduces formalin-induced nociception and tactile allodynia in diabetic rats VL - 577 SP - 203 KW - diabetes KW - formaldehyde KW - formalin KW - melatonin KW - nociception KW - tactile_allodynia AU - Arreolaespino, R AU - Urquizamarin, H AU - Ambriztututi, M AU - Araizasaldana, C AU - Caramsalas, N AU - Rochagonzalez, H AU - Mixcoatlzecuatl, T AU - Granadossoto, V PY - 2007/12/22/ UR - http://dx.doi.org/10.1016/j.ejphar.2007.09.006 ER -