Objective

2

To observe the effects of preconditioning with bian-stone patches at acupoints Neiguan (PC 6)

Taiyuan (LU 9)

and Renying (ST 9) on myocardial injury and oxidative stress in rats with acute hypobaric hypoxia.

Methods

2

36 male SD rats were randomly divided into the blank group

model group

patch group and drug group

with 9 rats in each. The blank group and model group were not given any interventions. Bian-stone patches were applied on the rats in the patch group at Taiyuan

Neiguan

and Renying points on both sides of the body and kept in place for 2 hours every day. Rats in the drug group were given 280 mg/kg of Rhodiola Capsule daily. After 14 days of intervention

all groups except the blank group entered the oxygen chamber which simulated the plateau environment at an altitude of 6000 m and stayed there for 24 hours. After they left the chamber

blood samples from the abdominal aorta and myocardial tissues were collected from the rats. The expressions of creatine kinase-MB (CK-MB)

cardiac troponin I (cTnI) and brain natriuretic peptide (BNP) in the serum and myocardium

and also the expressions of malondialdehyde (MDA)

hydrogen peroxide (H

2

O

2

) and hypoxia-inducible factor-1α (HIF-1α) in the myocardial tissues were determined by ELISA. The pathological changes of the myocardial tissues were observed and their water content were measured by HE staining.

Results

2

Pathological sections showed that the myocardial tissue cells in the model group were dissolved

broken and intercellular space widened. The pathological changes in the patch and drug groups were milder than those in the model group

and the hypoxic injury was not significant. Compared with the blank group

the myocardial water content in the model group was increased (

P

<

0.05)

the serum levels of CK-MB

cTnI and BNP were elevated (

P

<

0.05)

and the myocardial levels of CK-MB

cTnI

BNP

H

2

O

2

MDA and HIF-1α were raised (

P

<

0.05). The myocardial level of MDA in the patch group decreased (

P

<

0.05). Compared with model group

the myocardial water content in the patch group was increased (

P

<

0.05)

serum levels of CK-MB

cTnI and BNP were lowered (

P

<

0.05)

and the myocardial levels of CK-MB

cTnI

BNP

H

2

O

2

MDA and HIF-1α were reduced (

P

<

0.05). The levels of serum CK-MB and cTnI in drug group decreased (

P

<

0.05)

the levels of myocardial CK-MB

cTnI

BNP

H

2

O

2

and MDA were reduced (

P

<

0.05)

and the levels of myocardial water content

serum BNP and HIF-1α were decreased. Compared with drug group

the myocardial level of BNP in the patch group was lowered (

P

<

0.05).

Conclusion

2

Preconditioning with bian-stone patches at acupoints Neiguan

Taiyuan and Renying can improve the myocardial hypoxia of model rats

reduce the degree of oxidative stress

and alleviate the myocardial injury induced by hypobaric hypoxia

providing a new treatment idea and prevention measures for acute high altitude heart disease.