Neuronal induction of 72-kDa heat shock protein following methamphetamine-induced hyperthermia in the mouse hippocampus.
By means of an immunohistochemical technique, we examined the neuronal induction of 72-kDa heat shock protein (HSP72) in response to methamphetamine-induced hyperthermia in the mouse hippocampus. Strong HSP72 immunoreactivity (ir) was found in the neurons of hippocampus proper, particularly in the CA1/2 and medical CA3 subfields, at 10 h after drug injection. By 18 h, those neurons still revealed HSP72-ir, while neurons of the dentate gyrus also appeared positive for HSP72. At this stage, intense HSP72-ir was first detected in non-neuronal cells, i.e. glial and vascular endothelial cells. At 24 h, no apparent HSP72-ir was found in the hippocampal neurons, while only non-neuronal cells still revealed immunoreactivity for HSP72. In addition, no morphological evidence of cell degeneration or loss was noted in the CA1 sector or other hippocampal regions at 5 days after hyperthermic insult. In conclusion, (1) methamphetamine-induced hyperthermia per se is a stressful stimulant causing neuronal induction of HSP72 in the hippocampus neurons, particularly of CA1/2 and medial CA3 sectors, but does not prove fatal to the cells; (2) there is a cell type-specific difference in response to hyperthermic insult by inducing HSP72 and the timing of the induction response in the hippocampal formation; and (3) the animals that underwent drug-induced hyperthermia may be useful as an experimental model for the study of the protective mechanism of heat shock proteins against subsequent harmful stimuli.
Goto
S
S
Department of Neurosurgery, Kumanoto University Medical School, Japan.
Korematsu
K
K
Oyama
T
T
Yamada
K
K
Hamada
J
J
Inoue
N
N
Nagahiro
S
S
Ushio
Y
Y
D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D008694:Methamphetamine; D051379:Mice; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009474:Neurons / Q000378:metabolism*
D006360:Heat-Shock Proteins; D009419:Nerve Tissue Proteins; D008694:Methamphetamine