Capsaicin이 동통억제효과를 나타내는 기전에 관한 연구

Abstract

Capsaicin, the pungent algesic substance of the red pepper is known to be a neuro-toxic substance, interrupting the pain conducting pathway. To investigate the effects on the adult animals, histochemical, immunohistochemical and electronmicroscopical observation have been done after capsaicin treatment. Capsaicin 50mg/kg was injected subcutaneously to the adult rats and after 24 hours, 48 hours, 1 week and 1 month later, central nervous system, peripheral ilervous system were investigated. The results obtained are as follows ; 1. The immunoreactivity against substance P (SP) and calcitonin gene-related peptide (CGRP) in the (dorsal horn of spinal cord decreased by capsaicin treatment in adult rats and the effect was maximum after 1 week. It began to recover from 1 month after capsaicin treatment. 2. In the spinal ganglia, the number of CGRP and SP colltalning neurons decreased and these phenomen a were maximum in 1 week and began to recover from 1 month after capsaicin treatment. 3. In electronmicroscopical examination, the most sensitive part to capsaicin was ureter and it showed severe morphological changes after 24 hours. Dorsal root ganglia cells also showed changes after 24 hours. The other parts showed prominent changes after 1 week and they showed recovery from 1 month after capsaicin treatment. With the above results, the decrease of the B neurons which transmit pain in spinal ganglia and of the neurotransmitter, substance P and CGRP in the dorsal horn and spinal ganglia and destruction of the peripheral axons could be explain the mechanism of the analgesic effects of the capsaicin.