Calcium cytochemistry and stereological morphometry of the intercalated ductal cells of the pancreas.

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.

On the unity of cytomembrane system in the skeletal muscle.

In situ cytochemical evidence for specific Ca-binding sites in the cytomembrane system of skeletal muscle fibers is reported. High Ca accumulation was found at the junctions between different types of cytomembranes. Such junctions might represent "gate-locks" for intracellular Ca movements.

Folate metabolism in the superior cervical ganglion histochemical study.

By means of histochemical methods, folic acid, dihydrofolate reductase and NADH2-cytochrome-C-reductase were studied in the bovine superior cervical ganglion, in parallel with quantitative estimations of dihydrofolate reductase activity and in connection with the process of ageing. Various levels of folate metabolism were present in nerve cells and glial cells, as well as in pre or postganglionic nerves. In the process of ageing the activity of dihydrofolate reductase gradually decreased and the folic acid concentration in the nerve cells increased.