Brain serotonin depletion attenuates heatstroke-induced cerebral
ischemia and cell death in rats.
Kao, T. Y., and M. T. Lin.
Department of Physiology, National Cheng Kung University Medical
College, Tainan City, Taiwan, ROC.
APStracts 2:0410A, 1995.
In order to explore the importance of brain serotonin in the
heatstroke-induced cerebral ischemia and neuronal injury, we
evaluated the effects of heatstroke on brain serotonin release,
survival time, cerebral hemodynamic changes and neuronal cell damage
in rats with or without brain serotonin depletion produced by 5,7
-dihydroxytryptamine. In vivo voltammetry was used to measure changes
in extracellular concentrations of serotonin in the anterior
hypothalamus, striatum and frontal cortex. After the onset of
heatstroke, rats without brain serotonin depletion displayed
hyperthermia, decreased mean arterial pressure, increased
intracranial pressure, decreased cerebral perfusion pressure,
decreased cerebral blood flow, increased cerebral serotonin release
and increased cerebral neuronal damage, as compared to those of
normothermic controls. However, when the cerebral serotonin system
was destroyed by 5,7-dihydroxytryptamine, the heatstroke-induced
arterial hypotension, intracranial hypertension, ischemic damage to
the brain, and elevated cerebral serotonin release were reduced. In
addition, the survival time of the heatstroke rats was prolonged
after depleting brain serotonin. The data indicate that brain
serotonin depletion attenuates heatstroke-induced cerebral ischemia
and cell death in rats.
Received 27 March 1995; accepted in final form 6 September 1995.
APS Manuscript Number A332-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 31 October 95