1. 5-HT2A-mu opioid receptor mechanisms in the hypothalamus mediate interleukin-1β fever in rats
- Author
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Mao-Tsun Lin, Shu-Ming Tsai, Jhi-Joung Wang, and Chung-Ching Chio
- Subjects
Male ,Agonist ,medicine.medical_specialty ,Ketanserin ,Fever ,medicine.drug_class ,Hypothalamus ,Receptors, Opioid, mu ,Cyproheptadine ,Rats, Sprague-Dawley ,Opioid receptor ,Internal medicine ,medicine ,Serotonin 5-HT2 Receptor Antagonists ,Animals ,Receptor, Serotonin, 5-HT2A ,Receptor ,Dose-Response Relationship, Drug ,business.industry ,General Neuroscience ,Rats ,Endocrinology ,Opioid ,μ-opioid receptor ,business ,Body Temperature Regulation ,Interleukin-1 ,medicine.drug - Abstract
Direct administration of interleukin-1beta (IL-1beta) into the lateral cerebral ventricle of rat brain, in addition to inducing febrile responses, upregulated the immunoreactivity of tryptophan hydroxylase in the preoptic anterior hypothalamus. The fever induced by IL-1beta was significantly attenuated by pretreatment with intracerebroventricular injection of 5-HT2A receptor antagonists including cyproheptadine, ketanserin, or mianserin. In addition, the IL-1beta-induced fever was mimicked by intracerebroventricular administration of a 5-HT2A receptor agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-amionpropane (DOI). The DOI-induced (present results) or IL-1beta-induced (previous results) fever was further attenuated by pretreatment with an intracerebroventricular dose of mu-opioid receptor antagonists (e.g., buprenorphine or cyclic d-phe-cys-Try-d-Arg-Thr-pen-Thr-NH2) or 5-HT receptor antagonists (e.g., ketanserin or cyproheptadine). These findings suggest that a 5-HT2A-mu opioid receptor mechanism in the hypothalamus may mediate the IL-1beta fever.
- Published
- 2005
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