A HISTOLOGICAL STUDY ON THE HYPOPHYSIS OF THE CHINESE BUFFALO (Bubalus bubalis)

The histological structures of the hypophyses of 50 adult Chinese buffalos were studied by sections in sagittal,transverse and horizontal planes.Four stainig methods were used;Haematoxylin and Eosin(H-E),Periodic Acid Schiff PAS),Orange G(OG)and PAS-OG.The pars distalis is well developed.lt is apparently divided into three zones.The PAS-positive basophils are mostly localized in the highly vascular rostral portion,forming a basophil zone while the OG-positiv acidophils in the candal portion forming an acidophil zone.Between these two zones is the mixed zone of basophils and acidophils.The cells are grouped in clusters and cords or in follicles.There are numerous sinusoid capillaries.The pars tuberalis completely surrounds the infundibular stem.It appears highly vascularized and consists of undifferen-tiatied cells each with a dark staining nucleus and a scant amount of cytoplasm,chromophobe cells and a few PAS-positive basophils.They are arranged in tnbules or in follicles.NO acidophils were found.The pars intermedia is well developed,completely or mostly surrounding the pars nervosa.It is lobulated and consists of basophils and chromophobe cells arranged in clusters and cords or in follicles,but the lobules are bordered by a single layer of basophilic columnar cells.The cone of Wulzen was not found.The pars nervosa of the Chinese buffalo is relatively small.The median eminence is thickened mainly in the anterior part.The strongly PAS-positive colloid was found in all parts of the adeno-hypophysis and neurohypophysis in the mature Chinese buffalo.Comparisons were made of the morphological features of various parts of the hypophysis,distribution of cells and the occurrence of colloid of the Chinese buffalo with those of the ox or other animals.