Abstract
The effect of the 5-hydroxytryptamine (5-HT) precursor 5-hydroxytryptophan (5-HTP) on the thermoregulatory responses of unanesthetized rats were assessed at three different ambient temperatures (T a) of 8, 22 and 31°C. Intraperitoneal administration of either 5-HTP alone or 5-HTP plus R04-4602 (the peripheral decarboxylase inhibitor) produced dose-dependent hypothermia at bothT a's of 8 and 22°C. The hypothermia was brought about solely by a decrease in metabolic heat production at 8°CT a. At 22°CT a, the hypothermia was due to both a decrease in metabolic heat production and a increase in tail and footsole skin temperature. However, at 31°CT a, there were no changes in rectal temperature in response to either 5-HTP or 5-HTP plus R04-4602 application. The data suggest that an increase in 5-HT levels in brain decreases heat production and/or increase heat loss and leads to hypothermia in rats.
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Lin, M.T., Chow, C.F., Chern, Y.F. et al. Elevating serotonin levels in brain with 5-hydroxytryptophan produces hypothermia in rats. Pflugers Arch. 377, 245–249 (1978). https://doi.org/10.1007/BF00584279
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DOI: https://doi.org/10.1007/BF00584279