title: The role of the endogenous antioxidant enzymes and malondialdehyde in essential hypertension.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Physiology, JNMC, AMU , Aligarh, UP-202002, India .
authors.forename: Aquil
authors.initials: A
authors.lastname: Ahmad
authors.forename: Usha
authors.initials: U
authors.lastname: Singhal
authors.forename: Mohd Mobark
authors.initials: MM
authors.lastname: Hossain
authors.forename: Najmul
authors.initials: N
authors.lastname: Islam
authors.forename: Imran
authors.initials: I
authors.lastname: Rizvi
keywords: Catalase; Essential hypertension; Glutathione peroxidase; Oxidative Stress; Superoxide Dismutase Antihypertensive therapy
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