| 摘要: | Background: Increased systemic cytokines and elevated brain levels of monoamines, and hydroxyl radical
productions are thought to aggravate the conditions of cerebral ischemia and neuronal damage during heat
stroke. Dexamethasone (DXM) is a known immunosuppressive drug used in controlling inflammation, and
hydroxyethyl starch (HES) is used as a volume-expanding drug in cerebral ischemia and/or cerebral injury. Acute
treatment with a combined therapeutic approach has been repeatedly advocated in cerebral ischemia
experiments. The aim of this study is to investigate whether the combined agent (HES and DXM) has beneficial
efficacy to improve the survival time (ST) and heat stroke-induced cerebral ischemia and neuronal damage in
experimental heat stroke.
Methods: Urethane-anesthetized rats underwent instrumentation for the measurement of colonic temperature,
mean arterial pressure (MAP), local striatal cerebral blood flow (CBF), heart rate, and neuronal damage score. The
rats were exposed to an ambient temperature (43 degrees centigrade) to induce heat stroke. Concentrations of the
ischemic and damage markers, dopamine, serotonin, and hydroxyl radical productions in corpus striatum, and the
serum levels of interleukin-1 beta, tumor necrosis factor-alpha and malondialdehyde (MDA) were observed during
heat stroke.
Results: After heat stroke, the rats displayed circulatory shock (arterial hypotension), decreased CBF, increased the
serum levels of cytokines and MDA, increased cerebral striatal monoamines and hydroxyl radical productions
release, and severe cerebral ischemia and neuronal damage compared with those of normothermic control rats.
However, immediate treatment with the combined agent at the onset of heat stroke confers significant protection
against heat stroke-induced circulatory shock, systemic inflammation; cerebral ischemia, cerebral monoamines and
hydroxyl radical production overload, and improves neuronal damage and the ST in rats.
Conclusions: Our results suggest that the combination of a colloid substance with a volume-expanding effect and
an anti-inflammatory agent may provide a better resuscitation solution for victims with heat stroke. |
