PAIN AND ENVIRONMENT-WITH SPECIAL REFERENCE TO NOCICEPTOR SENSITIZATION AND EXPERIMENTAL ANALYSIS OF PAIN AGRAVATION INDUCED BY WEATHER CHANGES (LOW BAROMETRIC PRESSURE AND LOW TEMPERATURE) IN CHRONIC PAIN MODEL OF RATS

Abstract

Nociceptors that detect noxious environmental change and noxious event inside the body thus serving a defense mechanism are important for the survival of the organism. Activities of this receptors are sensitized by inflammatory mediators and sympathetic nerve activities. This sensitization of nociceptors is one of the hyperalgesia. Effects of inflammatory mediators (bradykinin, prostaglandins and histamine) on the viseral polymodal receptor, a type of nociceptor, were summarized. In addition, pain aggravating effects of simulated weather change (low atmospheric pressure and low temperature) on chronic pain model rats were demonstrated and possible contribution of sympathetic nerve excitation in these effects were discussed.