Article date: September 1977
By: B. COX, T.F. LEE in Volume 61, Issue 1, pages 83-86
Core and tail skin temperature was measured in rats which had guide cannulae implanted into their brains to allow drug injections directly into the preoptic anterior hypothalamus.
Apomorphine and dopamine (10 μg in 1 μl) injected into the area of the preoptic anterior hypothalamus caused a fall in core temperature which was preceded by a rise in tail skin temperature.
The decrease in core temperature following central injection of either apomorphine or dopamine was significantly reduced by pretreating rats for 2 h with pimozide (0.5 mg/kg i.p.).
Bilateral intrahypothalamic injection of pimozide (0.5 μg in 1 μl) significantly reduced the hypothermic effect of systemic apomorphine (1.25 mg/kg i.p.).
Control rats placed 65 cm below a 250 W infrared lamp responded with vasodilatation of tail skin blood vessels as indicated by an increase in tail skin temperature. Pimozide pretreatment (0.5 mg/kg i.p.) significantly reduced this response.
These results suggest that the preoptic anterior hypothalamus contains dopamine receptors which mediate hypothermia in rodents and raise the possibility that endogenous dopamine has a physiological role in thermoregulation.
Core and tail skin temperature was measured in rats which had guide cannulae implanted into their brains to allow drug injections directly into the preoptic anterior hypothalamus.
Apomorphine and dopamine (10 μg in 1 μl) injected into the area of the preoptic anterior hypothalamus caused a fall in core temperature which was preceded by a rise in tail skin temperature.
The decrease in core temperature following central injection of either apomorphine or dopamine was significantly reduced by pretreating rats for 2 h with pimozide (0.5 mg/kg i.p.).
Bilateral intrahypothalamic injection of pimozide (0.5 μg in 1 μl) significantly reduced the hypothermic effect of systemic apomorphine (1.25 mg/kg i.p.).
Control rats placed 65 cm below a 250 W infrared lamp responded with vasodilatation of tail skin blood vessels as indicated by an increase in tail skin temperature. Pimozide pretreatment (0.5 mg/kg i.p.) significantly reduced this response.
These results suggest that the preoptic anterior hypothalamus contains dopamine receptors which mediate hypothermia in rodents and raise the possibility that endogenous dopamine has a physiological role in thermoregulation.
DOI: 10.1111/j.1476-5381.1977.tb09742.x
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