Algogenic mediator-induced nociceptive response in diabetic mice.
The duration of the somatostatin-, bradykinin- or prostaglandin F2alpha-induced nociceptive response was significantly less in diabetic mice than in non-diabetic mice. Subcutaneous injection of 7-benzylidenenaltrexone (0.1, 0.3 and 1 mg/kg), an antagonist of delta1-opioid receptors, had no significant effect on either somatostatin-, bradykinin- or prostaglandin F2alpha-induced nociceptive responses in non-diabetic mice. 7-Benzylidenenaltrexone (0.1 and 0.3 mg/kg, s.c.) also had no significant effect on somatostatin- or prostaglandin F2alpha-induced nociceptive responses in diabetic mice. However, the bradykinin-induced nociceptive response in diabetic mice was dose-dependently and significantly increased when 7-benzylidenenaltrexone (0.1, 0.3 and 1 mg/kg, s.c.) was injected 10 min before the injection of bradykinin. These results suggest that a spinal delta1-opioid receptor-mediated endogenous antinociceptive system may inhibit the bradykinin-mediated nociceptive responses in the second phase of the formalin-induced nociceptive response in diabetic mice.
Kamei
J
J
Department of Pathophysiology and Therapeutics, Faculty of Pharmaceutical Sciences, Hoshi University, Tokyo, Japan. kamei@hoshi.ac.jp
Kashiwazaki
T
T
Taki
K
K
Hitosugi
H
H
Nagase
H
H
D000818:Animals; D001597:Benzylidene Compounds / Q000627:therapeutic use*; D001920:Bradykinin; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D015237:Dinoprost; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000627:therapeutic use*; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy*; D017465:Receptors, Opioid, delta / Q000037:antagonists & inhibitors / Q000187:drug effects*; D013004:Somatostatin
D001597:Benzylidene Compounds; D009292:Narcotic Antagonists; D017465:Receptors, Opioid, delta; C077358:7-benzylidenenaltrexone; D005557:Formaldehyde; D013004:Somatostatin; D009271:Naltrexone; D015237:Dinoprost; D001920:Bradykinin