[Ultrastructural features of pancreatic islet cells during prolonged glucose administration]. / Ul'trastrukturnye osobennosti kletok pankreaticheskikh ostrovkov pri dlitel'nom vvedeniia gliukozy.

The time course of ultrastructural changes in pancreatic islet cells was studied in experiments on albino male rats in prolonged administration of glucose at a dose of 15 g per 1 kg of body mass 3 times daily. Changes in the ultrastructures of beta-cells revealed in the first 10 days, indicated their functional tension. Later on (in 15-30 days) an increase in the level of blood serum immunoreactive insulin manifested itself in hypertrophy and hyperplasia of the intracellular structures of beta-insulocytes. An increase in the synthesis and excretion of insulin by beta-cells promoted the utilization of administered glucose manifesting itself in hypoglycemia on an empty stomach and a more intensive increment of the body mass of experimental animals. A relative volume of pancreatic islets over a studied period did not significantly change as compared with the control one.

[Morphogenesis of intralobular liver fibrosis in obstructive jaundice patients]. / Morfogenez vnutridol'kovogo fibroza pecheni bol'nykh obturatsionnoi zheltukhoi.

The results of ultrastructural study of the intralobular liver fibrosis in 38 patients with obstructive jaundice of various duration are presented. It is established that the appearance of fibroblast-like sinusoid cells plays a leading role in the development of intralobular liver fibrosis. The morphologic characteristics of poorly differentiated and differentiated cells of this type and their involvement in collagen fiber synthesis within liver lobules are given. It is shown that in obstructive jaundice a significant disturbance of the sinusoidal wall takes place due to the formation of collagen fibers, basal membrane that results in the worsening of the exchange between the blood and hepatocytes.

[Effect of glibenclamide on the ultrastructure of the islands of Langerhans and their insulin content]. / Vliianie glibenklamida na ul'trastrukturu pankreaticheskikh ostrovkov i soderzhanie v nikh insulina.

The ultrastructure of the pancreatic islets and insulin content in the beta-cells, revealed by histochemical technique after glybenclamide loading, was investigated in rats. Glybenclamide administration led to the loss in beta-cells of a greater portion of their hormone depot. Ultrastructurally, a significant development in all the organellae of the protein synthesizing apparatus was demonstrated, this testifying to a sharp rise of the hormone production. At the same time insulin released from the cells was accelerated, although no final and complete formation of beta-granules occurred, alpha-insulocytes appeared to be intact.

[Secretory cycle of pancreatic acinar cells in different functional states]. / Sekretornyi tsikl atsinarnykh kletok podzheludochnoi zhelezy pri razlichnykh ee funktsional'nykh sostoianiiakh.

Time parameter and secretory cycle in acinar cells of the pancreas were studied after atropine, trazilol, pilocarpine administration, and subtotal resection of the small intestine. The duration of secretory cycle was found to be about 45 min. in intact rats. Atropine and trazilol suppressed the secretion process, first inhibiting the release of the formed product and then reducing the synthesis. Pilocarpine first accelerated but very soon decreased the synthetic process. A marked acceleration of synthesis and intensification of secretory cycle in glandular cells occurred in postresectional period. Interrelationships of intracellular mechanisms for the product release and synthesis of new protein molecules, are discussed.

[Ultrastructural-cytochemical features of the plasma membrane of sodium-transporting cells]. / Ul'trastrukturno-tsitokhimicheskie osogennosti plazmaticheskoi membrany natriitransportiruiushchikh kletok

Electron microscopic and biochemical studies of the ATP-ase activity in different regions of the nephron and in the kidney microsomal fraction of the rat have revealed a pronounced increase of the total and Na+-+K+-ATP-ase activity in the process of compensatory hypertrophy. A decrease of the enzymatic activity was noted predominantly in proximal tubules under loading the animals by isotonic NaCl solution and after adrenalectomy--mainly in distal tubules. This speaks of the inhibition of the sodium-reabsorbing system in them. The transport of isotonic fluid in collecting tubes is accompanied by widening intercellular lacunae together with an increase of the ATP-ase activity of the lateral plasmic membrane of neighbouring cells. The data obtained suggest a close correlation between the electron-microscopically revealed ATP-ase activity of the plasmic membrane of tubular cells and the functional activity of the sodium-transporting system. A morphological equivalent of the sodium pump is a plasmolemma--mitochondrial pump which is characterized by: a) well developed foldness of the basal plasmic membrane where the enzymatic system is disposed; b) the high total and Na++K+-ATP-ase activity cytochemically and biochemically revealed; c) numerous regularly disposed mitochondria, having close contacts with the folds of the basal plasmic membrane.