ISSN:
1432-1912
Keywords:
Noradrenaline
;
Hypothalamus
;
Dopamine
;
Thermoregulation
;
6-Hydroxydopamine
;
Hyperthermia
;
Metabolism-vasoconstriction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary 1. Rats which had been pretreated with 3 intrahypothalamic doses of 10 μg of 6-hydroxydopamine (6-OHDA) to cause a selective depletion of hypothalamic noradrenaline to 26.7% of control hypothalamic noradrenaline maintained rectal temperature within the normal limits displayed by the control group. However, noradrenalinedepleted rats displayed a decrease in both cutaneous temperature and metabolic heat production in the cold (8°C). 2. Intrahypothalamic injections of 6-OHDA in normal rats at room temperature (22°C) caused an acute hyperthermia of up to 1.1°C which lasted for about 6 h. The acute hyperthermia in response to 6-OHDA was due to both cutaneous vasoconstriction and increased metabolism in the rat. Selective depletion of hypothalamic noradrenaline without affecting hypothalamic dopamine by prior treatment with 6-OHDA markedly reduced the hyperthermic responses to a subsequent dose of 6-OHDA. Therefore, the acute hyperthermic responses to 6-OHDA may be related to a release of noradrenaline in the hypothalamus. 3. The data indicate that activation of noradrenergic pathways in the hypothalamus facilities heat production and inhibits heat loss mechanisms in the rat.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00506192
Permalink
