[The effect of serotonin and histamine administered in low doses on body temperature]

Experiments on white rats and mice have shown that intraventricular administration of serotonin (10 mg) or intraabdominal administration of histamine (0.5 mg/kg) do not affect body temperature, whereas simultaneous administration of these drugs leads to a reliable drop of body temperature due to intensification of the heat output and the inhibition of heat production. These biogenic amines seem to act as the substances with additive hypothermal properties and, probably, are the components of natural antipyretic system of the warm-blooded organism.