The hypothermic effects of dl-tetrahydropalmatine in rats.
Systemic administration of dl-tetrahydropalmatine (THP; 10-50 mg x kg(-1) intraperitoneally) produced a proportional decrease in both colonic temperature and release of hypothalamic serotonin (5-hydroxytryptamine (5-HT)) in rats at room temperature. The hypothermia was brought about by cutaneous vasodilation and decreased metabolism. The THP- induced hypothermia was significantly attenuated in rats with brain 5-HT depletion produced by control injection of 5,7-dihydroxytryptamine or in rats with 5-HT2A receptor activation produced by 1-(2,5-dimethoxy-4-iodophenyl) -2-aminopropane, or in rats with 5-HT1A receptor antagonist produced by (-)-pindolol. The results suggest involvement of serotoninergic antagonism in the THP-induced hypothermia in rats
Lin
M T
MT
Department of Medical Research, Chi-Mei Medical Center, Yung-Kang City, 710, Tainan Hsien, Taiwan. mtlin@ym.edu.tw
Chueh
F Y
FY
Hsieh
M T
MT
D000818:Animals; D001600:Berberine Alkaloids / Q000494:pharmacology*; D001831:Body Temperature / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects*; D003106:Colon; D003864:Depression, Chemical; D007031:Hypothalamus / Q000378:metabolism; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000187:drug effects; D044263:Receptors, Serotonin, 5-HT1; D012701:Serotonin / Q000378:metabolism; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D001600:Berberine Alkaloids; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin; C014215:tetrahydropalmatine