Effects of hypothermia and hypoxia on superoxide dismutase and malondialdehyde in normal rabbits and rabbits with myocardial ischemia

Junjie HUANG; Shanmin ZHAO; Xianjiao HE; Lijuan HUANG; Ling JIN; Zuoren LIANG; Xianke LUO

ABSTRACT

BACKGROUND:

Previously, there are some researches on studying the effects of hypoxia or hypothermia singly. Nowadays, study on the synthetic action of hypoxia and hypothermia has been attached widely importance.

OBJECTIVE:

To explore the combination effects of acute hypothermia and hypoxia on superoxide dismutase(SOD) and malondialdehyde in normal rabbits and rabbits with myocardial ischemia.

DESIGN:

Randomized controlled trial.SETTING, MATERIALS and

INTERVENTIONS:

Experimental sitePhysiological Laboratory of Youjiang Ethnic Medical College. A total of 32 healthy rabbits weighed between 1.8to 2.5 kg were chosen. They were randomly divided into 4 groups each with 8 rabbits normal group, hypothermia and hypoxia group, ischemic group with normal temperature and oxygen,ischemic group with hypothermia and hypoxia. Normal rabbits and ischemic rabbits were put in fridge at low temperature( -10 ± 2) ℃ and low oxygen (oxygen content of 8.5% ) for one hour and tested activity of SOD and concentration of malondialdehyde in serum.MAIN OUTCOME

MEASURES:

Comparison of serum SOD and malondialdehyde between normal rabbits and myocardial ischemic rabbits under the acute hypothermia and hypoxia conditions.

RESULTS:

The SOD level of rabbits in hypothermia and hypoxia group [(371.04 ± 29.96) kNU/L] was much lower than that of normal temperature and oxygen group[ (424.09 ± 22.59) kNU/L] ( t = 5.21, P < 0.01) while the content of malondialdehyde[ (5.58 ± 0. 44) μ mol/L] was greater than that of normal group[ (4.44 ± 1.11) μ mol/L] ( t = 3.21, P < 0.05) . In myocardial ischemia group with hypothermia and hypoxia, SOD was greatly lower than that of myocardial ischemia group with normal temperature and oxygen(t=4.37, P < 0.01) while the malondialdehyde was greatly higher than that of ischemic group with normal temperature and oxygen group(t=2.94, P <0.05).

CONCLUSION:

The combined effects of acute hypothermia and hypoxia will aggravate the damage to body.