5-HT1A and 5-HT2 receptors mediate hypo- and hyperthermic effects of tryptophan in pargyline-pretreated rats.

Abstract

Mechanisms of tryptophan (a 5-HT precursor)-induced changes in body temperature were investigated in rats pretreated with pargyline, a monoamine oxidase inhibitor (MAO-I). Tryptophan (100 mg/kg, i.p.) did not affect the body temperature in rats, but it produced significant hypothermia followed by marked hyperthermia and higher mortality in the pargyline-pretreated rats. 5-HT depletion with p-chlorophenylalanine (p-CPA, 100 mg/kg/day for 3 days) significantly suppressed not only the body temperature change but also the mortality and 5-HT syndrome following tryptophan plus pargyline administration. Although propranolol (10 mg/kg, i.p.), a beta-adrenoceptor antagonist, did not alter the hypothermia caused by tryptophan in the pargyline-pretreated rats, pindolol (2 mg/kg, S.C.), a 5-HT1A receptor and beta-adrenoceptor antagonist, suppressed the hypothermia but not the hyperthermia or mortality caused by the same treatment. On the other hand, spiperone and ketanserin, 5-HT2 receptor antagonists, at doses of 3 mg/kg, potentiated the hypothermia and completely suppressed the hyperthermia and mortality caused by tryptophan in the pargyline-pretreated rats. These results suggest that tryptophan-induced hypo- and hyperthermia are mediated by 5-HT1A and 5-HT2 receptors, respectively, in the pargyline-pretreated pretreated rats.

Statistics

01020'02'04'06'08'10'12'14'16
Citations per Year

67 Citations

Semantic Scholar estimates that this publication has 67 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{AbdelFattah19955HT1AA5, title={5-HT1A and 5-HT2 receptors mediate hypo- and hyperthermic effects of tryptophan in pargyline-pretreated rats.}, author={Ahmed F. Abdel-Fattah and Koichi Matsumoto and K A el-Hady and Hideaki Watanabe}, journal={Pharmacology, biochemistry, and behavior}, year={1995}, volume={52 2}, pages={379-84} }