Thyroxine Accelerates Healing of Acetic Acid-Induced Gastric Ulcer in Rats

Abstract

Studies have shown that disturbed thyroid states may predispose the gut to ulcer formation, suggesting that thyroid hormones play important roles in gastroprotection. It is not known however if the gland and its principal hormones affect the processes leading to the healing of already formed gastric ulcers. Therefore this study was designed to investigate the effects of thyroid hormones on healing of acetic acid induced gastric ulcer. Male albino rats (160 – 200g) were divided into four groups viz: control, thyroidectomised, thyroidectomised with thyroxine treatment (100μg/kg/day) and Sham operated animals treated with thyroxine. After 35 days of drug treatment and/or surgery, ulcer was induced in stomach of animals using acetic acid. Ulcer healing was assessed 3, 7 and 10 days post-ulcer induction. Ulcer area was measured by planimetry. Blood cells were counted and tissue regeneration was studied using histology technique. Ten days post ulcer induction, thyroxine treatment significantly increased the rate of ulcer healing (0.81 ± 0.02mm2/day) when compared with control (0.46±0.05 mm2/day) while thyroidectomy significantly reduced the rate of ulcer healing (0.28 ± 0.05mm2/day). Thyroxine treatment increased the rate of clearing of inflammatory cells, fibroblast proliferation, collagen deposition and epithelial cell proliferation while thyroidectomy delayed these processes. Thyroxine treatment significant increased while thyroidectomy decreased white blood cell on day 7. We conclude that thyroid hormones accelerate gastric ulcer healing by accelerating inflammatory and proliferative phases of healing and increased white blood count during healing while thyroidectomy delayed these processes.