| Abstract: | Using K-antimonate procedure, Ca2 binding sites in pancreatic small ductal cells were studied. Great precipitates were observed in the lumen of intercalated ducts, on luminal, contraluminal and lateral plasmalemma of centroacinar cells and in some of their organelles especially in mitochondrial matrix as well as on the euchromatin. Fine precipitates were present mainly on the endomembranes of perinuclear cisternae, endoplasmic reticulum, Golgi vesicles, mitochondria, secretory vesicles. Stereological studies showed in electron micrographs great differences from one cell type to another for the volume of mitochondria: 8% in acinar cell, 4.8% in centroacinar cell, 15.3% in small ductal cell and 4% in endocrine cell. The results strongly support the idea that centroacinar and intercalated ductal cells constitute the segments of pancreatic excretory cells, where the alkalinization of pancreatic juice takes place mainly by the secretion of bicarbonate and resorption of chloride ions. |
