Inhibition of adjuvant-induced inflammatory hyperalgesia in rats by local injection of neurotrophin-3

• Published in: Neuroscience letters Vol. 282; no. 1; pp. 61 - 64
• Main Authors: Watanabe, Machiko, Endo, Yukihiro, Kimoto, Kosuke, Katoh-Semba, Ritsuko, Arakawa, Yoshihiro
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 17.03.2000; Elsevier
• Subjects: Adjuvant; Animals; Biological and medical sciences; Freund's Adjuvant; Fundamental and applied biological sciences. Psychology; Hindlimb; Hyperalgesia; Hyperalgesia - immunology; Hyperalgesia - metabolism; Immunoenzyme Techniques; Inflammation; Inflammation - immunology; Inflammation - metabolism; Male; Nerve growth factor; Nerve Growth Factor - metabolism; Nerve Growth Factor - pharmacology; Neurotrophin 3 - metabolism; Neurotrophin 3 - pharmacology; Neurotrophin-3; Pain Measurement; Pain sensitivity; Rats; Rats, Wistar; Skin; Somesthesis and somesthetic pathways (proprioception, exteroception, nociception); interoception; electrolocation. Sensory receptors; Vertebrates: nervous system and sense organs; Pain sensitivity; Neurotrophin-3; Rats; Nerve growth factor; Adjuvant; Inflammation; Skin; Hyperalgesia; Nociception; Vertebrata; Sensitivity; Mammalia; Pain; Rat; Rodentia
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(00)00842-9

The induction of nerve growth factor (NGF) in inflammatory tissue has been shown to be involved in hyperalgesia. In the present study, the role of neurotrophin-3 (NT-3) in the regulation of inflammatory hyperalgesia was analyzed. Inflammatory hyperalgesia was induced by intraplantar injection of complete Freund's adjuvant (CFA) to the rat hind paw. NT-3 levels in the plantar skin were much higher than NGF levels (1.24 and 0.14 ng/g tissue, respectively) before CFA injection, but decreased significantly 6 h to 48 h after the injection while NGF was markedly induced at 6 h but decreased thereafter. When 1 μg of NT-3 was locally injected at 5 h after CFA injection at the time NT-3 levels decreased, hyperalgesia was reversed transiently but specifically. These results suggest an inhibitory role of NT-3 in the regulation of pain sensitivity.