Effects of 6-hydroxydopamine and pimozide on temperature maintenance by the chicken.
Intraventricular implants of pimozide in adult white leghorn hens were used to block dopamine (DA) receptors, and 6-hydroxydopamine (6-OHDA) was injected intraventricularly to destroy the noradrenergic system locally. The hens were exposed to ambient temperatures of 5 and 35 degrees C, and their core temperature was measured. One hundred micrograms of 6-OHDA significantly reduced the norepinephrine (NE) but not the DA content of the hypothalamus and reduced the uptake of [3H]NE but not of [3H]DA by synaptosomes in vitro. Neither of the drug treatments nor their combination affected average core body temperature (Tb) at either 5 or 35 degrees C. Pimozide treatment caused a lower maximum Tb at 35 degrees C and a higher maximum Tb at 5 degrees C than the control treatment. No evidence was obtained that 6-OHDA treatment affected body temperature regulation. It is concluded that neither the DA nor the NE system is essential for normal temperature maintenance in the hen exposed to either 5 or 35 degrees C.
D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D002645:Chickens / Q000502:physiology*; D003080:Cold Temperature; D005260:Female; D006358:Hot Temperature; D006892:Hydroxydopamines / Q000494:pharmacology*; D010868:Pimozide / Q000494:pharmacology*; D011941:Receptors, Adrenergic / Q000502:physiology; D011954:Receptors, Dopamine / Q000502:physiology
D006892:Hydroxydopamines; D011941:Receptors, Adrenergic; D011954:Receptors, Dopamine; D010868:Pimozide