| Abstract: | While indomethacin treatment did not alter the urinary excretion of noradrenaline in the rat at room temperature, it consistently and significantly augmented the urinary hyperexcretion of noradrenaline induced by exposure to cold; the excretion of adrenaline remained initially unchanged. The effect of indomethacin increased progressively with time during the experimental period of about one week. The results imply that indomethacin, which is known to be able to block the formation of PGE in vivo as well as in vitro, augments the secretion of nor-adrenaline from sympathetic nerves during sympathetic hyperactivity. Since the amount of noradrenaline secreted as a result of nerve stimulation is raised when PGE formation is depressed, in isolated tissues in vitro, the present result may imply that the sympathetic hyper-secretion induced by indomethacin was secondary to suppression of PGE formation. |
