Effect of sub-hypothermia on blood pressure of rats with experimental cerebral infarction

Tao LI; Chengyan LI; Shaozu YU

ABSTRACT

BACKGROUND:

Sub-hypothermia has been widely used to treat cerebral infarction. Whether sub-hypothermia treated on body surface affects blood pressure or not, or the effect is advantageous or disadvantageous should be researched further.

OBJECTIVE:

To observe the effect of sub-hypothermia on blood pressure of rats with experimental cerebral infarction so as to investigate its influence on cerebral protective function.

DESIGN:

Randomized controlled study.

SETTING:

Neurological Department of Renmin Hospital of Wuhan University.MATERIALS The experiment was completed in the Neurological Laboratory of Renmin Hospital of Wuhan University. Totally 120 SD rats were selected and divided randomly into control group and experimental group with 60 in each group.

METHODS:

Rats in experimental group were maintained at 4 ℃ 3 hours after MCA obstruction, and rectal temperature was maintained at (34±1.0) ℃;rats in control group were maintained at room temperature (20 ℃). All animals were reperfused 2 hours after MCA obstruction. Heart rate,breath, blood oxygen saturation, anus temperature and blood pressure were assayed with monitor. Rats were sacrificed under anesthesia after 24 hours, and cerebral tissue was taken out to measure the total volume of infarct focus.MAIN OUTCOME

MEASURES:

① Changes of heart rate, breath,blood oxygen saturation, · mean arterial blood and blood pressure of rats in the two groups before and after treatment; ② volume of infarct focus of rats in the two groups.

RESULTS:

① Values of blood pressure in both groups were increased after obstruction as compared with those before obstruction [(150±7.2),(129±5.7) mm Hg; (149±7.5), (130±2.2) mm Hg, P ＜ 0. 01], and there was not significant difference (P ＞ 0.05). Blood pressure was decreased obviously in sub-hypothermia group at the beginning of sub-hypothermia (P＜ 0.01). ② Volume of cerebral infarction was obviously smaller in subhypothermia group than that in control group [(153.17±26.83) mm3,(251.45±36.70) mm3, P ＜ 0.01].

CONCLUSION:

Sub-hypothermia can both reduce the volume of cerebral infarction and decrease the blood pressure obviously.