Effect of ascorbic acid on long-term cold exposure induced changes in thyroid activity in Sprague Dawley rats.

OBJECTIVE

To determine the effect of ascorbic acid supplementation on long-term cold exposure induced changes in thyroid activity in Sprague-Dawley rats.

STUDY DESIGN

Experimental study.

PLACE AND DURATION OF STUDY

Physiology Department of Islamic International Medical College, Rawalpindi, National Institute of Health, Islamabad and Railway Hospital, Rawalpindi, from January to December 2009.

METHODOLOGY

Ninety Sprague-Dawley rats were randomly divided into three groups of control, cold exposed and cold exposed along with ascorbic acid supplementation. After one month, their thyroid levels were analyzed by using chemiluminescent immunometric assay on Siemens Immulite 2000 Analyzer.

RESULTS

After 4 weeks of cold exposure to experimental animals, the thyroid activity was raised significantly in the cold exposed group as compared to the control group (p-value for T3 difference = 0.004, T4 difference = 0.002 and TSH difference < 0.001). Supplementation with ascorbic acid in the third group normalized the thyroid hormone activity with p-value for difference in levels of T3 being 0.6661, T4 = 0.027 and TSH = 0.0028.

CONCLUSION

Ascorbic acid prevented the cold induced changes in thyroid hormone levels in rodents.