AIM To observe the protective effect of hot water bath (hydrotherapy) on stress induced myocardial injury.
METHODS Eighteen adult male Sprague-Dawley rats were randomly divided into control group, stress group and post-stress hot water bath intervention group (water bath group). Rats in the stress group and the water bath (WB) group were subjected to a 4-weeks foot electric shock combined with noise (4 h/d) and the rats in the WB group were given hot bath intervention (38-40 ℃). Body weight, blood pressure and cardiac functions were measured during the experiment and serum stress hormones and myocardial enzymes were measured after 4 weeks. Myocardial protein was determined by immunofluorescence and Western Blot, and the structure of myocardial mitochondria was observed by electron microscope.
RESULTS The concentrations of NE and AngII in the serum of rats in the stress group were higher than those in the control group (P<0.05) and the levels of CK and LDH in the stress group increased (P<0.05). Further, compared with those in the control group, the positive staining of microtubule-associated protein 1 light chain 3B (LC3B) and the expressions of LC3II/I, p62 and Beclin1 in myocardial tissue in the stress group increased (P<0.05). Mitochondria showed decreased number and structural disorder in the stress group. Importantly, the hot water bath intervention decreased serum NE, Ang II concentrations and CK and LDH levels compared with those in the stress group (P<0.05). In addition, hot water bath significantly decreased p62 and Beclin1 expression levels (P<0.05) and reversed the mitochondrial structural damage.
CONCLUSION Hot water bath reduce myocardial autophagy, improves mitochondrial structure and alleviates chronic stress induced myocardial injury where the mechanisms need further studies.
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