The Effect of Calcitonin Gene-related Peptide on Antinociception in Midbrain Periaqueductal Grey in Rats with Inflammation / 昆明医科大学学报

ABSTRACT

Objective To investigate the effect of intra-periaqueductal grey(PAG) injection of calcitonin gene-related peptide(CGRP) on antinociception in rats with inflammation.Methods Subcutaneous injection of 0.1 mL of 2% carrageenan into the plantar region of the left hindpaw,after which,the effect of intra-periaqueductal grey injection of calcitonin gene-related peptide on the hindpaw withdrawal latency to thermal stimulation and hindpaw withdrawal threshold to mechanical stimulation was observed.Results(1) Subcutaneous injection of 0.1 mL of 2% carrageenan into the plantar region of the left hindpaw induced a significant increase in the volume of the ipsilateral hindpaw,and a significant bilateral decrease of the hindpaw withdrawal latency to thermal stimulation and hindpaw withdrawal threshold to mechanical stimulation.(2) Intra-periaqueductal grey injection of 0.26 nmoL or 0.52 nmoL of CGRP,instead of 0.13 nmoL induced a significant increase of the hindpaw withdrawal latency to thermal stimulation and hindpaw withdrawal threshold to mechanical stimulation.Conclusion CGRP in periaqueductal grey was involved in antinociception in rats.