[The evaluation of level of epigenetic indicator--5-methylcytosine in smoking and non-smoking patients with mild essential hypertension].

5-methylcytosine (m5C, 5mC) is a nucleotide occurring naturally in genomic DNA and play an important role in regulation of genes expression. Methylation of cytosine in DNA is an epigenetic modification and different intrinsic and extrinsic factors can influence on its level. For example, it is subject to modification and/or degradation by the free radicals which are commonly present in environment of human, among others the cigarette smoke. The reactions of m5C with free radicals lead to origination of many products which effect is decrease of level of m5C in DNA (hypomethylation) and excessive expression of genes inducing development of different diseases, especially cardiovascular system diseases. The aim of the study was statement if exist differences of level of 5-methylcytosine in DNA between smoking and non-smoking patients suffering from mild essential hypertension. The study group was composed of 30 patients suffering from mild essential hypertension (21 females and 40 males) aged from 18 to 55 years (32.4+/-10.3 years). The group of smoker was composed of 13 patients (5 females and 8 males) and the group of non-smokers was composed of 17 patients (7 females and 10 males). 3-5 ml of blood was sampled on EDTA and then thin-layer chromatography analysis of 5-methylcytosine level in DNA after previous enzymatic hydrolysis of DNA and radioactive phosphorus labeling [32p] was performed. The mean level of 5-methylcytosine (m5C) were 1.30+/-0.56 [%] in non-smoking patients, and 1.28+/-0.42 [%] in smoking patients suffering from mild essential hypertension. There is no significant statistically differences between non-smoking and smoking patients (p>0.4). In the study the following conclusion was drawn: the level of m5C in DNA of patients suffering from mild essential hypertension in the study is independent of smoking (p>0.4) in patients with mild essential hypertension. However it supposes, out of regard for theoretic datum suggestive such influence, the study should be performed in more frequent group of patients.