Effect of long term food-restriction [low-caloric diet] on pars distalis of the anterior pituitary gland of adult male albino rats: a biochemical and histological study

ABSTRACT

Nowadays, many people are interesting to reduce their weight and improve their health by decreasing the calories through decreasing the food intake. Long term food restriction affects the function of many organs. Studying the changes of the pars distalis of anterior pituitary gland histologically and biochemically in food restricted rats. Sixteen adult male albino rats were divided into; control and experimental group. In experimental group, the food supply was restricted to 60% of the mean food supply of the control group for three months. Blood samples were obtained to evaluate the levels of thyroid stimulating hormone [TSH], follicle stimulating hormone [FSH], luteinizing hormone [LH], adrencorticotrophic hormone [ACTH], growth hormone [GH] and prolactin hormone. The pituitary glands were dissected and prepared for light and electron microscopic examination. In the food-restricted rats, there was a non significant change in ACTH and prolactin, a significant decrease in FSH and a highly significant decrease in TSH, GH and LH. Microscopic examination revealed that many somatotrophs, mammotrophs, gonadotrophs and thyrotrophs exhibited similar changes in the form of swollen mitochondria with loss of their internal cristae and reduction in the amount of secretory granules. Some degenerated cells showed irregular small nuclei with condensed chromatin. The corticotrophs were less affected and most cells were more or less similar to those of control group. In food restricted rats the somatotrophs, mammotrophs, gonadotrophs, and thyrotrophs cells showed morphological changes that can be correlated with the biochemical findings. On the other hand, corticotrophs were less affected. These changes might explain the recorded disturbed functions of many organs in human on low-caloric diet