Influence of Dietary Factors on the Ultrastructural Integrity of Anterior Pituitary Corticotrophs

Modern dietary habit is believed to be a contributory factor for stress including metabolic and physiological stress. Two primary stress hormones are adrenocorticotrophic hormone (ACTH) and corticosterone where corticotroph in the anterior pituitary gland releases ACTH through hypothalamus-pituitary-adrenal (HPA) axis stimulation leading to the production of corticosterone. This study investigates the effect of different diet at the ultrastructure of corticotrophs in the anterior pituitary gland. 35 male Sprague-Dawley rats (eight weeks old) were divided into five groups according to the diet they were fed, namely control (normal rat chow), high-fat diet, high-protein diet, high-sugar diet, and high-starch diet. The rats were acclimatized 2 weeks prior. Feeding was done for eight weeks with tap water provided ad libitum. At the end of the eight weeks, the rats were euthanized, their pituitary gland harvested, fixed and processed for ultrastructural analysis using electron microscope. High-fat and high-sugar diet affected the corticotroph ultrastructure the most, respectively. Shrunken nucleus, disruption of nucleus membrane, damaged mitochondria and swollen endoplasmic reticulum can be seen mainly in the respective high-fat and high-sugar diet groups. There is a strong correlation between certain types of diet and the ultrastructural integrity of corticotrophs, which is responsible for the production of hormones related to stress.