Haloperidol reduces the sympathetic and thermogenic activation induced by orexin A.
This experiment tested the effect of haloperidol on the sympathetic and thermogenic effects induced by orexin A. The firing rates of the sympathetic nerves to interscapular brown adipose tissue (IBAT), along with IBAT and colonic temperatures and heart rate were monitored in urethane-anesthetized male Sprague-Dawley rats before and 5 h after an injection of orexin A (1.5 nmol) into the lateral cerebral ventricle. The same variables were monitored in rats with an intraperitoneal administration of haloperidol (1 mg/kg bw), a D(2) receptor antagonist. The results show that orexin A increases the sympathetic firing rate, IBAT and colonic temperatures and heart rate. This increase is reduced by the haloperidol. These findings suggest that dopaminergic system is activated during the orexin A-induced hyperthermia.
Monda
M
M
Department of Experimental Medicine, Section of Human Physiology, Second University of Naples, via Costantinopoli 16, 80138 Naples, Italy. marcellino.monda@unina2.it
Viggiano
A
A
De Luca
V
V
D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D000320:Adrenergic Fibers / Q000187:drug effects* / Q000502:physiology*; D000818:Animals; D001831:Body Temperature / Q000187:drug effects / Q000502:physiology; D001833:Body Temperature Regulation / Q000187:drug effects* / Q000502:physiology*; D002352:Carrier Proteins / Q000008:administration & dosage / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D006220:Haloperidol / Q000008:administration & dosage / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006979:Hyperthermia, Induced; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology; D000068797:Orexins; D051381:Rats; D017207:Rats, Sprague-Dawley; D012540:Scapula / Q000294:innervation / Q000378:metabolism
D002352:Carrier Proteins; D018492:Dopamine Antagonists; C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D006220:Haloperidol