[Pretreatment with aspirin for protection against heat stroke in rats].
OBJECTIVE
To observe the changes in blood pressure and interleukin-1beta (IL-1beta) level after heat stroke in rats and to observe the protective effect of pretreatment with aspirin against heat stroke.


METHODS
Rat models of heat stroke were established and randomly assigned into control (n=10) and aspirin groups (n=10). Arterial blood pressure, colonic temperature (T(co)), and electrocardiograph (ECG) were monitored and blood samples taken at 0 and 60 min after heat exposure for determining the plasma IL-1beta levels in the two groups.


RESULTS
From 0 to 50 min after heat exposure, the mean arterial blood pressure  MAP  was not significantly different between the two groups, but at about 55-60 min, the MAP significantly decreased in the control group in comparison with the aspirin group (P<0.01). The K value and the height of the dicrotic notch (h(D)/H) were gradually decreased, especially at 40 min after heat exposure, and the control group showed greater reduction in the K value. T(co) of both groups were increased after heat exposure, without significant difference between groups. The time of the onset of heat stroke was similar in the two groups, but rats in the aspirin group had significantly longer survival time (P<0.05). ECG showed that the heart rate and QT intervals of both groups were increased, while PR intervals were decreased after heat exposure. Plasma IL-1beta levels in the two groups were significantly elevated at 60 min in comparison with the basal level (P<0.05), which was more obvious in the control group (P<0.05).


CONCLUSIONS
Pretreatment with anti-inflammatory dose of aspirin can provide protection against heat stroke in rats, which may be associated with the inhibition of elevation of plasma IL-1beta levels by aspirin.
Song
Xu-dong
XD
Department of Cardiology, Zhujiang Hospital, First Military Medical University, Guangzhou 510282, China. songxd@yeah.net
Chen
Ai-hua
AH
Luo
Bing-de
BD
Zou
Fei
F
D000818:Animals; D001241:Aspirin / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D004562:Electrocardiography; D018883:Heat Stroke / Q000401:mortality / Q000503:physiopathology / Q000517:prevention & control*; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000097:blood; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D007375:Interleukin-1; D001241:Aspirin