Some Observations upon the Cytology of the Pars Distalis of the Surgically-removed Human Pituitary
Human anterior pituitary tissue that had been removed at operation and immediately fixed was examined by a number of cytological and histochemical methods and by phase contrast and electron microscopy, and compared with similar material obtained post mortem. The general histological picture of good post-mortem material (not more than 4 hours post mortem) compared well with the surgically-removed tissue. For the study of silver impregnations of the Golgi substance, however, material removed at operation was found to be greatly superior. Evidence was obtained showing that the intracellular lipid inclusions seen post mortem were not artifacts resulting from cytolytic changes. There appeared to be no relationship between these lipid bodies and the Golgi material as revealed by the Aoyama method. No unequivocal dimorphism of the Golgi bodies, correlated with α- and β-cells, such as has been reported to occur in certain other mammals, was observed. Phospholipid was present in the granules of a substantial proportion of the α-cells. It was found that most of the cells which had been designated as β-cells after the application of certain routine staining methods, and most of the Gram-positive cells, reacted positively to the Periodic acid Schiff test: these cells could therefore be regarded as true β- or mucoid cells. A method for the demonstration in frozen sections of the cell-types, together with the lipid inclusions, is described.