Histological structure of the pituitary gland of carnivores

Abstract

The histological structure of the pituitary gland was studied in 26 carnivorous mammals (10 American mink, 10 domestic cats and 6 silver-black foxes). The studies were carried out at the Department of Anatomy and Physiology of the Federal State Budgetary Educational Institution of Higher Education of the Novosibirsk State Agrarian University and based on the experimental fur farm of the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences during 2023-2024. The pituitary glands were examined topographically after removal of the skull bones, and examined microscopically after fixation of the material in 10% neutral buffered formalin solution. The prepared sections were stained with hematoxylin and eosin and then examined by light microscopy followed by photographing the major structures. The study established the topography of the pituitary gland on the ventral surface of the brain. The study of histologic sections showed that in the studied animal species the pituitary gland is well developed, divided into anterior (adenohypophysis) and posterior (neurohypophysis) lobes, separated from each other by the pituitary cleft. The pituitary gland in all animals was surrounded by dura mater. All parts of the adenohypophysis - distal, tuberal and intermediate - were observed in the adenohypophysis. The distal part of the adenohypophysis consisted of three main cell types: acidophils, basophils and chromophobic cells. Acidophils were smaller than basophils and chromophobes were the largest cells. The tuberal part consisted predominantly of chromophobe cells and sinusoidal capillaries. The intermediate part contained clusters of chromophobic and basophilic cells. The neurohypophysis contained unmyelinated nerve fibers among which numerous pituicytes were scattered. The data obtained coincided with the histologic structure of the pituitary gland of other carnivorous mammals.