Modification of delayed radiation-induced reactions of duodenal vessels and mast cells in old rats.

Pronounced ultrastructural changes in vessels and mast cells were observed in duodenal lamina propria of Wistar rats 1 year after single whole-body gamma-irradiation in a dose of 7.5 Gy. Inhibition of adrenocortical function with methopyrone reduced structural damage and improved animal survival.

[The behavior of 125I microspheres of serum albumin in the body of rabbits administered the preparation selectively into the renal artery]. / Povedenie 125I-mikrosfer syvorotochnogo al'bumina v organizme krolikovv pri selektivnom vvedenii preparata v pochechnuiu arteriiu.

Intraarterial selective injection of serum albumin microspheres into the kidney resulted in embolization of the vessels with microspheres of different sizes. In vivo radiometry made it possible to improve the localization of microspheres and their distribution in the animals' bodies at varying time of observation. Pathomorphological investigations showed optimum sizes of microspheres causing prolonged retention of microparticles at the site of injection without considerable morphological changes of body tissues. The method of using microspheres as a radionuclide carrier was shown to hold promise for therapeutic purposes.

[The effect of chronic butyphos poisoning on protein and nucleic acid synthesis in various rat organs and activity of blood cholinesterase]. / Vliianie khronicheskoi intoksikatsii butifosom na sintez belka i nukleinovykh kislot v razlichnykh organakh krys i aktivnost' kholinésterazy krovi.

Two doses of butyphos (1/10 and 1/50 LD50) were administered into rats within 6 months. Content of DNA was distinctly decreased in liver and kidney tissues within the first 2 weeks of the pesticide administration. Then DNA synthesis was increased 2-fold in liver tissue and remained high during all the 6 months of intoxication. Protein synthesis was increased in liver tissue within 3 months of the administration and remained elevated up to the end of experiment. High rate of protein synthesis, found in kidney and spleen tissues at the initial steps, was markedly decreased within 6 months. Content of DNA and RNA was decreased in the tissues studied within 1 month of the intoxication and restored within 3 months, while it remained at considerably lower level in liver and spleen tissues as compared with control values. Cholinesterase activity was lowered by 90% in blood within 11 weeks with the subsequent increase; but in the experimental group intoxicated with butyphos at 1/10 LD50 the enzymatic activity constituted only 60% of control values within 6 months. Histological study showed development of necrodystrophy in liver tissue and of fibroplastic glomerulonephritis in kidney. The deteriorating effect of butyphos on cellular genome functions appears to relate not only to its cytotoxicity but also to the cancerogenic and mutagenic properties of the pesticide.

[Ultrastructure of the vessels of the submucosal membrane of the rat small intestine at long intervals following fractionated irradiation]. / Ul'trastruktura sosudov podslizistoi obolochki tonkoi kishki krys v otdalennye sroki posle fraktsionirovannogo oblucheniia.

The time course of ultrastructural changes in the walls of arterial type vessels was studied in the small intestinal submucous membrane of Wistar male rats long after fractionated irradiation of the abdominal area. Three phases were identified in the development of vascular response to irradiation; mechanisms of their development are under discussion.

[Protective and repair processes in the small intestine during radiation exposure]. / Zashchitnye i vosstanovitel'nye protsessy v tonkoi kishke pri radiatsionnom vozdeistvii.

The small intestine as a complex heterostructural organ possesses morphofunctional defence-regenerative mechanisms. All elements of this mechanism suffer in irradiation of the organ especially at ionizing radiation doses causing the acute intestinal syndrome. Regenerative processes in the small intestine are suppressed not only by ionizing radiation but also by the toxic products of exo- and endogenous origin resulting from irradiation of the body.

[Liposome transport as a model of substance absorption in the small intestine studied by electron microscopic autoradiography and scanning microscopy]. / Issledovanie transporta liposom v kachestve modeli vsasyvaniia veshchestv v tonkoi kishke metodom élektronno-mikroskopicheskoi avtoradiografii i skaniruiushchei mikroskopii.

Using electron microscope autoradiography and scanning microscopy, evidence was provided on the space-time character of the transport of enterally introduced liposomes containing 125I-lecitin and 3H-cholesterine. Liposomes underwent degradation on the mucous surface of the epithelial cells, followed by the appearance of monolayer vesicles to be transported to the glycocalix area between the microvilli. This is accompanied with the release of the radioactive trait from liposomes and its transporting to enterocytes.

[Transport of 125I-poly I : poly C incorporated in liposomes from the enteric cavity to the small intestine mucosa. An electron microscopic autoradiographic study]. / Transport 125I-poliI : poliTs, zakliuchennogo v liposomy, iz énteral'noi sredy v slizistuiu tonkoi kishki. Issledovanie metodom élektronno-mikroskopicheskoi avtoradiografii.

Transport of 125I-poly(I) : poly(C) incorporated into liposomes trough the small intestine mucose was investigated by electron microscopic autoradiography. With the migration of liposomes into the mucous layer on the luminal surface of the intestine up to the glycocalix level of microvilli these undergo degradation with the formation of monolayer liposomes from which polynucleotide is released. Later on the poly(I) : poly(C) or its fragments transported through the enterocytes to be accumulated in cells of the connective tissue stroma of the small intestine mucose. Part of polynucleotide was incorporated up to the arterial and lymphoid capillary level. Apparently, on the way of its transport the polynucleotide is affected by pancreatic and tissue nucleases. The accumulation of polynucleotide in macrophages, fibroblasts, lymphocytes, plasma cells and smooth muscle cells was traced. It is supposed that the polynucleotide accumulated in stroma of the small intestine mucose may preserve its interferon inducing activity.

[Enzymes in the mucosal layer of the small intestine]. / Fermenty sloia slizi tonkoi kishki.

It has been demonstrated by the methods of histochemical and biochemical examination of the activity of the enzymes that the mucus layer covering the small intestinal wall contains active enzymes (alkaline phosphatase, leucin aminopeptidase IV, saccharase, lactase) and pancreatic enzymes (alpha-amylase and trypsin). Emphasis is laid on the enrichment of the mucus layer with pancreatic enzymes as compared with small intestinal juice. A hypothesis has been advanced according to which the mucus layer undergoes degradation of polymeric and oligomeric substrates, which plays a physiological part in the digestion of nutritive substances and protection of the internal medium against immunoactive biopolymers. The digestion occurring in the mucus layer is proposed to be called mucus digestion.

[The effect of vincristine on the morpho-functional state of the rat small intestine]. / Vliianie vinkristina na morfofunktsional'noe sostoianie tonkoi kishki krys.

The effect of vincristine treatment on the morphofunctional status of the small intestine was studied morphologically in 80 Wistar rats. The drug was found to possess a general toxic effect. Diarrhea was matched by the arrest of crypt cell-proliferation at metaphase, lysis, a decreased disaccharidase activity and increased levels of cytoplasmic alkaline phosphatase and dipeptidyl(amino)peptidase-IV in enterocytes of the villi. Exudation and degenerated cell organellae prevailed in intramural nervous ganglion cells, smooth muscle cells of intestinal tunica muscularis and vessels and in endothelium. The said changes were transitory in epithelium, but never regressed in nervous structures. At later stages (6-12 months after vincristine, but never regressed in endothelium. The later stages (6-12 months after vincristine treatment), secondary dystrophic changes developed in the small intestine wall, being predominantly confined to neuromuscular and vascular elements.

[Absorption routes of stearic acid and leucine in the small intestine of the rat after gamma irradiation]. / Puti vsasyvaniia stearinovoi kisloty i leitsina v tonkoi kishke krysy posle gamma-oblucheniia.

The aim of the investigation was to study transport of 3H-stearic acid in ultrastructural compartments of epitheliocytes during absorbtion, resynthesis and translocation of lipids having the form of chylomicrons after a local large fractionated gamma-irradiation of the rat small intestine with a total dose of 35 Gr. In the anesthesized animals the ligated fragments of the jejunum, which kept their blood supply and innervation, were separated, fatty emulsion with 3H-stearic acid (a label) was administered into their lumen. Intensity of the label incorporation was quantitatively estimated in the electron microscopic autographs every 2, 5, 10 and 20 min after the isotope administration. Time distribution of the label concentration after irradiation characterized the sequence of the transport stages of 3H-stearic acid across microvilli and the terminal reticulum (MV + TR) triglycerides resynthesis in the agranular and granular endoplasmic reticulum (AER, GER), chylomicrons formation in Golgi complex (GC), as well as their exudation into the lacunar intercellular space (LIS), basal membrane and capillaries. Transport deceleration of the label at the level MV + TR and decreasing synthesis of triglycerides in GER was accompanied with a delay in the chylomicrons formation in the GC and their excretion into the LIS. Conglomerates of the aggregated chylomicrons were formed in the LIS. The radioautographic data on 3H-leucine incorporation characterized a decreased activity of the protein-synthesizing system of epitheliocytes.

[Electron microscopic study of 3H-leucine transport between the internal body environment and the enteral environment]. / Elektronno-mikroskopicheskoe issledovanie transporta 3H-leitsina mezhdu vnutrennei sredoi organizma i énteral'noi sredoi.

Using electron microscopic autoradiography, a space-time characteristics of 3H-leucine transport, from the enteral to the inner environment, and from blood plasma to the enteral environment, has been given. Some gradient of intracellular leucin accumulation is determined, from the tip cells of a villus to epithelocytes of the basal membrane. Amino acid transport from blood plasma to the lumen of the intestine is accomplished mainly via the cytoplasm and intercellular space of epithelocytes of the villus basement. It is proposed that amino acid transport through membranes of microvilli and through basal-lateral membranes of cells being on various levels along the villus may start at different amino acid concentrations which may be, presumably, to different concentration and different conjugation of enzyme-transport complexes in these membranes.

[Effect of peritol on the functional and morphological characteristics of the small intestine in rats]. / Vliianie peritola na funktsional'nye i morfologicheskie kharakteristiki tonkoi kishki krys.

Experiments were made on 140 male Wistar rats with the use of morphological, biochemical and radiometric research methods. It was established that as soon as the treatment with the anabolic drug peritol was completed, there appeared the morphological signs attesting to an increase in functional activity of vasculostromal elements of the small intestine, and the absorption rate of vitamin B12 got intensified. Activity of enzymes responsible for parietal digestion (alkaline phosphatase, invertase), absorption of 59Fe-citrate and 131I-albumin were unchanged. No substantial changes were revealed on the part of the morphology and function of the small intestine in the long-term period after peritol administration.

[Absorption study of 3H-stearic acid in the rat small intestine using electron microscopic autoradiography]. / Issledovanie vsasyvaniia 3H-stearinovoi kisloty v tonkom kishechnike krysy metodom élektronno-mikroskopicheskoi avtoradiografii.

Using electron microscope autoradiography evidence was provided on the space time character of the absorption, resynthesis, transfer and exocytosis of lipids in the form of chylomicrons; this evidence correlating with data on distribution in the subcellular compartments of epithelial cells of the intestine. The majority of fatty acid enters the lymph in the form of resynthesized lipids. Part of fatty acid is transported from the enteral environment to the internal one, escaping from the stages of esterification and triglyceride and chylomicron formation in the endoplasmic reticulum and Golgi apparatus.

[Mucosal ultrastructure of the rat small intestine after flight on the Kosmos-936 biosatellite]. / Ul'trastruktura slizistoi obolochki tonkoi kishki krys posle poleta na biosputnike "Kosmos-936".

The mucous membrane of the small intestine midportion of rats from the flight (weightless and centrifuged), synchronous and vivarium groups was examined electron microscopically. Ultrastructural changes were seen in all experimental groups, although their level and rate of recovery were different. Artificial gravity on Cosmos-936 did not influence those changes significantly. The data obtained suggest that the above changes are morphological manifestations of the reaction of rat small intestine to the combined effects of space flight factors.

[Morphological changes in the digestive organs during prolonged space flight on the Kosmos-782 biosatellite]. / Morfologicheskie izmeneniia organov pishchevareniia pri dlitel'nom kosmicheskom polete na biosputnike "Kosmos-782".

A reduction in the content of neutral mucopolysaccharides in mucous cells of the neck, a slight decrease in the activity of succinate dehydrogenase and NAD-diaphorase in parietal cells, a decrease in the DNA synthesis rate, and an increase in the area of mitochondria and cristae were detected in the gastric mucosa of rats which were in a long-term space flight. In the small intestine, an increase in the activity of glucose-6-phosphate dehydrogenase and leucine aminopeptidase were found. Morphological changes in the liver consisted in infiltrative adiposity. A similar morphological picture was demonstrated in a synchronous experiment on the earth. These changes, however, were nonspecific and reversible (25 days after rehabilitation the picture did not differ from the animal house control).