ROLE OF CATECHOLAMINE IN EFFECTS OF TRAUMA ON THERMOREGULATION, STUDIED IN RATS TREATED WITH 6-HYDROXYDOPAMINE

  • 1 January 1977
    • journal article
    • research article
    • Vol. 58  (1) , 42-49
Abstract
Rats in which central noradrenergic terminals were damaged by injecting 6-hydroxydopamine (6-OHDA) into the cerebral ventricular system were used to study the possible role of noradrenaline (NA) in the effect of trauma on thermoregulation. In non-injured rats the 6-OHDA treatment did not affect the threshold environmental temperature (Ta) for the onset of shivering or the slope of the regression lines relating intensity of shivering to Ta. It raised the core temperature (Tc) threshold for the opening of the A-V [arterio-venous] anastomoses in the tail. Whereas in normal rats ischemic limb injury depresses the threshold Ta for the onset of shivering without altering the slope of the regression line, in 6-OHDA-treated rats no depression of the threshold Ta was observed during limb ischemia but the slope of the regression line was lower. The Tc threshold for the opening of the A-V anastomoses in the tail was the same as in the 6-OHDA-treated controls. The injection of NA into a lateral cerebral ventricle of a normal rat in a 5.degree. C environment inhibited shivering and lowered Tc. The 6-OHDA treatment did not induce hypersensitivity to the injection of NA by this route. NA may be concerned in the central inhibition of shivering during limb ischemia.