Tissue Specific Effects of Chronic Sustained Hypoxia on Oxidative Stress: Role of Cilnidipine, a Dual L/N Type Calcium Channel Blocker.

ABSTRACT

Background: Blood flow, metabolic rate and oxygenrequirements of an organ guide the extent of oxidativestress experienced by any tissue in response to chronichypoxia. Currently cilnidipine is used in themanagement of hypertension and its antioxidant actionsare gaining wide interest. Aim and Objectives: Toevaluate the tissue specific effects of chronic sustainedhypoxia with regards to oxidative stress in the contextof cilnidipine. Material and Methods: Twenty fouradult male Wistar strain albino rats were randomlyassigned into four groups group 1, control, normoxia(21% O ); group 2, chronic hypoxia (CH) (10% O ) for 2 221 days; group 3, normoxia + cilnidipine (Cil) for 21days; group 4, chronic hypoxia + cilnidipine (CH+Cil)for 21 days. Following 21 days of intervention bloodwas collected and animals were sacrificed and liver,lung and heart were collected. Serum MDA and MDAin tissue homogenate of liver, lung and heart wereestimated. Results: Our results demonstrate theelevated serum MDAlevels in chronic hypoxia exposedrats (group 2). We also observed increased MDAin liverfollowed by lung and least in the heart in chronichypoxia exposed rats (group 2). Treatment withcilnidipine reduced serum MDA and heart MDA levelsin cilnidipine treated chronic hypoxia exposed rats(group 4). However cilnidipine did not have anyinfluence on MDA levels in the liver and lung in samegroup of rats. Conclusion: The results demonstratetissue specific effects of chronic sustained hypoxia withthe highest oxidative stress observed in the liverfollowed by the lung. Although oxidative stress is alsoobserved in the heart it is the least in comparison to theliver and the lung. Cilnidipine, a dual L/N type calciumchannel blocker demonstrated beneficial antioxidantactions only in the heart supporting the cardioprotectiverole of cilnidipine