Effects of thyroid hormone supplementation on oxidative stress after sleeve gastrectomy in rats

Aim: Sleeve gastrectomy has been used for the surgical treatment of morbid obesity. The aim of the present study was to determine the effects of triiodothyronine supplementation on oxidative stress parameters in anastomotic tissue level. Material and Methods: Twenty-four male Wistar albino rats were divided into control (n:12), and experimental (n:12) groups and underwent sleeve gastrectomy. Experimental group rats received a single dose of triiodothyronine (400 mg/100 g) in the operation day. Rats were sacrificed on postoperative day 7. Serum thyroid hormones were analysed. The supernatants were used to measure total oxidant status, total antioxidant status, nitric oxide and malondialdehyde levels. All tissue parameters were analysed by spectrophotometric methods. Oxidative stress index values were calculated. Results: Thyroid stimulating hormone levels in both the control and triiodothyronine group did not significantly change on the 7th postoperative day (p=0.663). Free triiodothyronine levels were significantly higher in triiodothyronine group rats than in control group rats (triiodothyronine vs control: p=0.004). Although total oxidant status levels did not altered by thyroid hormone treatment (p>0.05), total antioxidant status levels significantly decreased (p0.05). Tissue nitric oxide levels were also similar in both groups (p>0.05). Malondialdehyde levels increased in triiodothyronine given rats compared with the control group (p<0.01). Conclusion: This study showed that total oxidant status levels and oxidative stress index values were similar in both groups. However, triiodothyronine supplementation induced lipid peroxidation by increasing tissue malondialdehyde levels that might deplete tissue antioxidant level