Sympatho-adrenal involvement in methamphetamine-induced hyperthermia through skeletal muscle hypermetabolism.
We investigated the involvement of the sympatho-adrenal axis in the hyperthermia induced by methamphetamine by using a biotelemetric system. The intraperitoneal injection of methamphetamine (1 mg/kg) induced hyperthermia preceded by an increase in oxygen consumption in freely moving rats. The hyperthermic effect of methamphetamine was completely blocked by chemical sympathectomy with 6-hydroxydopamine (50 mg/kg, i.p.). Adrenalectomy, but not adrenal demedullation, prevented the hyperthermia. In adrenalectomized rats, dexamethasone supplementation (0.5 mg/kg, s.c.) restored the methamphetamine-induced hyperthermia. Furthermore, dantrolene (1 or 2 mg/kg, i.v.), which blocks Ca2+ release from the sarcoplasmic reticulum in skeletal muscle, attenuated the hyperthermia. These results suggest that methamphetamine stimulates norepinephrine release from sympathetic nerve terminals, which then enhances thermogenesis in skeletal muscle under the permissive action of glucocorticoids.
Makisumi
T
T
Department of Legal Medicine, Yamaguchi University School of Medicine, Ube, Japan.
Yoshida
K
K
Watanabe
T
T
Tan
N
N
Murakami
N
N
Morimoto
A
A
D000311:Adrenal Glands / Q000503:physiopathology*; D000315:Adrenalectomy; D000818:Animals; D001831:Body Temperature; D005334:Fever / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D008694:Methamphetamine; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000502:physiology; D010101:Oxygen Consumption; D051381:Rats; D017208:Rats, Wistar / Q000601:surgery; D013562:Sympathectomy; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013997:Time Factors
D008694:Methamphetamine