Effect of Glutamine supplementation on histological and some pathophysiological parameters of the male rat with induced hypothyroidism by propylthiouracil (PTU)

The study was conducted to evaluate the histological and some physiological parameters in male rats with induced hypothyroidism by propylthiouracil (PTU) for 30 and 45 days and the effect of glutamine (Gln) supplementation on thyroid recovery and enhanced its physiological function. The results revealed a highly significant decrease in T4 in rats of the hypothyroid group during 30 and 45 days than the control group (72.23±9.82M mol/L). The treated group with Gln had a significant increase in T4 post 30 and 45 days compared to hypothyroidism and control groups. The results also showed differences in TSH levels in rats as a significant increase in the hypothyroid group for 30 and 45 days with a mean of (15.65±7.01 and 18.85±7.95U UI/ml, respectively). The mean concentration of TSH in rats with hypothyroidism treated with Gln showed a significant decrease compared to the hypothyroidism group. The results also showed a highly significant decrease in iron and ferritin levels in comparison to the control group post 30 and 45 days, with mean ferritin concentrations of 7.56±2.64 and 4.71±1.43ng/ml. The results revealed that iron and Ferritin level of hypothyroid rats treated with Gln was increased compared to the hypothyroidism group. The results of histological examinations in rats with induced hypothyroidism post 30 days showed thyroid follicles with variable size and shapes, lining with simple cuboidal epithelial cells, interfollicular adenomatosis, scanty or mild colloid within follicles lumen, congested blood vessels, inactive follicles have squamous epithelium with vesicular nuclei, vacuolated cytoplasm and moderate depletion of Para follicular cells. Also, severe alternations were observed post 45 days of induction like disintegrated thyroid follicles, shrunken and atrophied, hyperemia, hyperplasia, heavy infiltration of inflammatory cells, and congested large blood vessels. Moreover, the sections of treated with Gln post 30 and 45 days showed regenerated follicles and recovery of normal parenchymal tissue, the follicles grouped as lobules, each follicle lining with simple cuboidal epithelium, and a moderate amount of colloid material.