title: Alteration in dopamine metabolism in the thermoregulatory center of exercising rats.
abstract: To examine the role of monoamines and amino acids in thermoregulation, we measured their concentrations in the preoptic area and anterior hypothalamus (PO/AH) in exercising rats, using an in vivo microdialysis technique. Body temperature (Tb) was monitored using a telemetry system. Tb increase by about 1.0 degrees C in the first 15 min of treadmill exercise (10 m/min; for 60 min), and was maintained thereafter at a steady high level possibly due to activation of the heat loss system. The levels of dopamine metabolites (3,4-dihydroxyphenylacetic acid and homovanillic acid) in the PO/AH significantly increased during exercise. However, exercise did not induce an increase in the level of either serotonergic substances (5-hydroxytryptamine and 5-hydroxyindoleacetic acid) or amino acids (aspartate and glutamate). Our data indicate that dopamine breakdown processes in the PO/AH are activated during exercise. Dopamine in the PO/AH may be involved in the heat loss mechanisms for thermoregulation when Tb rises during exercise.
authors.affiliation: Department of Biology, Faculty of Science, Tokyo Metropolitan University, Hachioji, Tokyo, Japan. hasehiro@hiroshima-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Hasegawa
authors.forename: T
authors.initials: T
authors.lastname: Yazawa
authors.forename: M
authors.initials: M
authors.lastname: Yasumatsu
authors.forename: M
authors.initials: M
authors.lastname: Otokawa
authors.forename: Y
authors.initials: Y
authors.lastname: Aihara
mesh_terms: D000818:Animals; D007025:Anterior Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism*; D001831:Body Temperature / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism*; D018846:Excitatory Amino Acids / Q000378:metabolism; D008297:Male; D017551:Microdialysis / Q000706:statistics & numerical data; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism; D010805:Physical Conditioning, Animal / Q000706:statistics & numerical data; D011301:Preoptic Area / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism
chemical_list: D018846:Excitatory Amino Acids; D012701:Serotonin; D004298:Dopamine