DNA Damage in Lymphocytes in Hypertensive Subjects in Bangladesh

Abstract

Oxidative stress due to imbalance between the production of reactive oxygen species and their dismutation is claimed to be higher in hypertensive subjects than normotensive subjects. In hypertensive subjects oxidative stress may damage deoxy-ribonucleic acids (DNA). In this study plasma superoxide dismutase (SOD) activities, protein carbonyl contents (PCCs) and extent of DNA damage in lymphocytes were measured in specimens obtained from 86 subjects to compare oxidative stress and oxidative DNA damage between normotensive and hypertensive subjects and to assess their relationship with the degree of blood pressure. Results were expressed as mean±SD. Two-tailed unpaired t test and Pearson's correlation test were done to compare or to determine the relationship between groups or variables. SOD activities were 2.85±0.12 unit/mg protein and 3.84±0.45 unit/mg protein (p<0.05) in hypertensive and normotensive groups respectively. PCCs were 4.77±0.36 nmol/mg protein and 3.75±0.23 nmol/mg protein in hypertensive and normotensive groups respectively. Olive tail moments (OTM) were 124.7±11.69 units and 108.9±9.27 units in hypertensive and normotensive groups respectively. The correlation coefficient of OTM was 0.3924 (p<0.05) for diastolic blood pressure and 0.3618 (p<0.05) for systolic blood pressure. Oxidative stress and DNA damage was higher in hypertensives than normotensives and DNA damage correlated positively with blood pressure.

DNA damage and arterial hypertension. A systematic review and meta-analysis

“…4B, Table 1, 2) (ref. [8][9][10][11][12][13][14][15][16][17][19][20]22 ). Meta-analysis showed an average mean difference between hypertensive patients and healthy controls of 7.5 (6.6; 8.6) ng/mg creatinine for 8OHdG and 14.7 (6.4; 23.0) from the Comet assay (Fig.…”

“…Surprisingly, regarding BP, the correlation was found for humans only for comet assay in blood (r=0.362), not for 8OHdG (ref. 12 ), and more strongly in animals with comet assay in tissue 28 . Among the parameters in which only 8OHdG was tested (high-density lipoprotein cholesterol (HDL), triacylglycerol (TAG), heart rate (HR), body mass index (BMI), brachial-ankle pulse wave velocity (PWV), ischemia modified albumin (IMA), prooxidant-antioxidant balance (PAB), protein carbonyl (PCO), advanced oxidation protein products (AOPPs), extent of coronary heart disease (CHD), total thiol (T-SH)), only serum glycosylated haemoglobin (HbA1c) showed a stronger positive correlation (8OHdG; urine: r=0.670, P<0.0001) (ref.…”

“…Comet assay was tested in strictly untreated HT (4 studies; N=215 pts) (ref. 8,9,11,12 ). These data are very important, to exclude artefacts in changes as DNA damage induced by medication.…”

“…The effects of different substances (especially vasodilators, vasoconstrictors, mechanical interventions) on different DNA damage types in HT animals were tested [24][25][26][27][28][29][30][31][32][33] . Regardless of antihypertensive pharmacotherapy, a majority of the selected studies demonstrated significantly higher DNA damage in HT 731 pts (349 pts; comet assay; blood) and (382 pts; 8OHdG; 122 in blood and 260 in urine) compared to controls [8][9][10][11][12][13][14][15][16][17]19,20,22 .…”