Thyroid gland in free radical-induced oxidative stress

Abstract

This oxidative stress has been implicated in a variety of pathological conditions such as diabetes mellitus, inflammation, cancer, ageing, ischemia, atherosclerosis, liver damage, etc. The present study revealed that all the stressors invariably increase oxidative stress in all the tissues as evident from the markers of oxidative stress, i.e., LPO, SOD, CAT, and GSH, in various tissues like blood, muscle, and liver. It was also found that chemical stress produces maximum oxidative stress as compared to physiological and psychological stress. Similarly, changes in the markers of oxidative stress in blood parallel with changes in muscle and liver. In all the stressed conditions, there was an increase in T 3 and T 4 and decrease in TSH. There was a concurrent increase in LPO and decrease in the SOD and CAT activity and reduction in the reduced glutathione content in blood. The data on oxidative stress and blood levels of thyroid hormones T3 and T4 condition exhibited a linear correlation. The changes in thyroid hormone levels correlate with the parameters of oxidative stress. Hence, it can be contemplated that thyroid hormones may play a pivotal role in the induction of oxidative stress in stress-exposed subjects.