The role of the endogenous antioxidant enzymes and malondialdehyde in essential hypertension.

CONTEXT: Oxidative Stress is caused by an imbalance between the production of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates. AIMS: 1. To compare the levels of Malondialdehyde (MDA), in hypertensive and normotensive subjects. 2. To compare the levels of the antioxidant enzymes, namely, Catalase, Glutathione peroxidase (GPX) and Superoxide Dismutase (SOD) in hypertensive and normotensive subjects. 3. To determine the correlation between the MDA levels and the mean arterial pressure (MAP) among hypertensive subjects. 4. To determine the correlation between the antioxidant enzyme levels and MAP among the hypertensive subjects and to evaluate the effect of 6 months of antihypertensive therapy with a tight blood pressure control on the MDA levels. Materials and Methods : In this cross sectional study, 25 normotensive and 40 hypertensive subjects were recruited. The hypertensive subjects were further subdivided into three subgroups: Prehypertensives, Stage I hypertensives and Stage II hypertensives. All the subjects underwent a blood pressure measurement and the markers of oxidative stress in their sera were estimated. The subjects of Stage I hypertension and Stage II hypertension were given antihypertensive treatment for 6 months and their blood pressures were tightly regulated and brought to the normotensive state. After 6 months, the estimations of the markers of oxidative stress were done again. RESULTS: The MDA levels were significantly increased in the stage I and stage II hypertension groups as compared to those of the control group (p<0.05). The antioxidant enzymes (SOD, Catalase and GPX) were significantly decreased (p<0.05) in the prehypertension and in the stage I and stage II hypertension groups as compared to those in the control group. There was a significant increase in the levels of the antioxidant enzymes after 6 months of a tight regulation and bringing of the blood pressure to the normotensive state by giving antihypertensive therapy. CONCLUSION: On comparison of the present study with other studies in which the use of antioxidants were found to be ineffective in the blood pressure reduction, it can be concluded that oxidative stress is an effect rather than a cause of essential hypertension.

Serum tumor necrosis factor-alpha in pre eclampsia.

Cytokines are major contributors in pathogenesis of pre eclampsia. Serum TNF-alpha was determined in 10 normal and 30 pre-eclamptic pregnant females with special reference to maternal age, parity and levels of mean arterial blood pressure. TNF-alpha was determined using sandwich ELISA technique. Serum TNF-alpha level in normal pregnant females was 9.3 +/- 0.56 pg/ml, while in pre-eclamptic pregnant females it was 67.66 +/- 61.83 pg/ml. This increase TNF-alpha was highly significant (P < 0.001). There was no significant changes in serum TNF-alpha with respect to maternal age, parity and mean arterial pressure in both normal and pre-eclamptic pregnancies.