Formalin-induced nociceptive responses in diabetic mice

• Published in: Neuroscience letters Vol. 149; no. 2; pp. 161 - 164
• Main Authors: Kamei, Junzo, Hitosugi, Hideki, Kasuya, Yutaka
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 12.01.1993; Elsevier
• Subjects: Analgesics - administration & dosage; Analgesics - pharmacology; Animals; Behavior, Animal - drug effects; Biological and medical sciences; Diabetes; Diabetes Mellitus, Experimental - drug therapy; Diabetes Mellitus, Experimental - metabolism; Dose-Response Relationship, Drug; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Formaldehyde - pharmacology; Formalin; Injections, Spinal; Male; Medical sciences; Mice; Mice, Inbred ICR; Naltrexone - administration & dosage; Naltrexone - analogs & derivatives; Naltrexone - pharmacology; Naltrindole; Narcotic Antagonists - administration & dosage; Narcotic Antagonists - pharmacology; Nociception; Nociceptors - drug effects; Receptors, Opioid, delta - drug effects; Spantide; Substance P; Substance P - administration & dosage; Substance P - analogs & derivatives; Substance P - pharmacology; Nociception; Formalin; Naltrindole; Diabetes; Substance P; Spantide; Endocrinopathy; Opiate receptor δ; Diabetes mellitus; Rodentia; Vertebrata; Experimental disease; Mammalia; Pain; Mouse; Animal; Antagonist; Streptozotocin
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/0304-3940(93)90761-9

In non-diabetic mice, s.c. injection of formalin to the hindpaw had a biphasic effect: an immediate nociceptive response (first-phase) followed by a tonic response (second-phase). However, only the immediate nociceptive response was observed in diabetic mice. The duration of the first-phase response was significantly longer in diabetic mice than in non-diabetic mice. In diabetic mice, when spantide, an antagonist of substance P, reduced the duration of the nociceptive response in the first-phase to the levels that were observed in non-diabetic mice, the second-phase response appeared. The second phase also became apparent in diabetic mice after pretreatment with naltrindole (3 mg/kg), an antagonist of δ-opioid receptors. These results suggest that a negative control system, which is mediated by δ-opioid receptors and links substance P with somatostatin-mediated nociceptive transmission, may inhibit the formalin-induced second-phase of the nociceptive response in diabetic mice.