Сryotherapy combined with cord blood injection improves myocardium structure in obese rats.

Abstract

The numbers of obese people is still growing in developed countries. Obesity is often associated with an increased risk of coronary heart disease and hypertension. The goal of our study was to assess and compare influences of sole and combined use of rhythmic extreme whole-body cryotherapy (RE WBC) and cord blood nucleated cells (CBNCs) injection on myocardium structure in obese young rats. The experiments were approved by the Committee on Bioethics at the Institute for Problems of Cryobiology and Cryomedicine of NAS of Ukraine. The whole cooling cycle included 9 procedures (3 procedures/day) of cooling (2 min each) for 5 days with a day interval. Immediately after cooling the skin temperature declined within the range of 3–5 °С, the rectal temperature did not change significantly. Thawed CBNCs preparation was injected intraperitoneally in dose of (1–3)×105 CD34+- cells/kg (after the ninth procedure in RE WBC+CBNCs group). The preparation was made up to 1 ml volume with plasma autologous to the cells. The rats were decapitated 30 days after the last cooling procedures and/or the injection, and the pieces of myocardium tissue were taken for a histological study. Myocardium structure was assessed in histological specimens stained with hematoxylin and eosin, van Gieson's picrofuchsin. The signs of circulatory disorders, myocardium hypertrophy, interstitial and perivascular edema, and focal cardiosclerosis were indicated in obese rats. After combined application of RE WBC and CBNCs these signs were poorly expressed. The morphological signs of neoangiogenesis were noted. This means improving blood flow and trophism of the heart, hindering the development of ischemia and necrosis, which allows maintaining an increased number of cardiomyocytes, as well as providing their needs for hypertrophy of the myocardium, directly associated with the diet-induced obesity. Thus, the combined application of RE WBC and CBNCs can improve myocardium structure in obese young rats.