Inhibition of the preoptic area and anterior hypothalamus by tetrodotoxin alters thermoregulatory functions in exercising rats

被引:59
作者
Hasegawa, H
Ishiwata, T
Saito, T
Yazawa, T
Aihara, Y
Meeusen, R
机构
[1] Free Univ Brussels, Dept Human Physiol & Sports Med, B-1050 Brussels, Belgium
[2] Hiroshima Univ, Fac Integrated Arts & Sci, Exercise Physiol Lab, Higashihiroshima 724, Japan
[3] Tokyo Metropolitan Univ, Grad Sch Sci, Dept Biol, Tokyo 158, Japan
关键词
thermoregulation; heat dissipation; heat production; microdialysis;
D O I
10.1152/japplphysiol.00916.2004
中图分类号
Q4 [生理学];
学科分类号
071003 ;
摘要
We have previously demonstrated a functional role of the preoptic area and anterior hypothalamus (PO/AH) in thermoregulation in freely moving rats at various temperature conditions by using microdialysis and biotelemetry methods. In the present study, we perfused tetrodotoxin (TTX) solution into the PO/AH to investigate whether this manipulation can modify thermoregulation in exercising rats. Male Wistar rats were trained for 3 wk by treadmill running. Body core temperature (T-b), heart rate (HR), and tail skin temperature (T-tail) were measured. Rats ran for 120 min at speed of 10 m/min, with TTX (5 mu M) perfused into the left PO/AH during the last 60 min of exercise through a microdialysis probe ( control, n = 12; TTX, n = 12). T-b, HR, and T-tail increased during the first 20 min of exercise. Thereafter, T-b, HR, and T-tail were stable in both groups. Perfusion of TTX into the PO/AH evoked an additional rise in T-b (control: 38.2 +/- 0.1 degrees C, TTX: 39.3 +/- 0.2 degrees C; P < 0.001) with a significant decrease in T-tail ( control: 31.2 +/- 0.5 degrees C, TTX: 28.3 +/- 0.7 degrees C; P < 0.01) and a significant increase in HR ( control: 425.2 +/- 12 beats/min, TTX: 502.1 +/- 13 beats/min; P < 0.01). These results suggest that the TTX-induced hyperthermia was the result of both an impairment of heat loss and an elevation of heat production during exercise. We therefore propose the PO/AH as an important thermoregulatory site in the brain during exercise.
引用
收藏
页码:1458 / 1462
页数:5
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