Morphofunctional changes in the exocrine pancreatic cells in acute experimental pancreatitis in rats

Experimental pancreatitis was induced by cooling the splenetic part of rat pancreas with chlorethyl, and the cells of duodenal area of the pancreas were studied at different stages of pancreatitis using cytomorphometry, cytomorphology and autoradiography. Interlobular and interacinar oedemas were observed at the first hours after treatment. In 24 hours the intracellular oedema of exocrine pancreatic cells (EP) was detected. On day 14 after treatment typical acute edematous pancreatitis developed. The observed changes involve a pathological activation of EP of the duodenal area, a subsequent restoration of the structure of this area, and later a passage of pancreatitis into the chronic form. The usefulness of this model of pancreatitis for quantitative cytochemical studies of EP during pathogenesis and drug treatment is discussed.     

A simple and rapid experimental protocol for studies of nucleic acids metabolism and their base composition.

A suitable, simple and rapid protocol for metabolic studies of nucleic acids and determining their base composition, using reversed-phase high-performance liquid chromatography is described. Modified classic methods of isolation of the nucleic acids fraction from a biological material, in our particular case Artemia sp., were used. Then analysis of their constituents and the incorporated radioactivity, after hydrolytic processes, was performed by high-performance liquid chromatography under isocratic conditions, with 9 min total retention time. This method may be applied in several aspects of nucleic acids research, such as molecular cloning or metabolic and phylogenetic studies.     

Changes in the serum protein composition in experimental hypercholesterolemia

Cholesterol accumulation, quantitative changes and composition of lipoproteins, total proteins of blood serum and protein fractions obtained by acid extraction are studied in hypercholesterinemia dynamics in rabbits. It is found that the initial period of cholesterinosis in blood serum is marked by an increased content of total proteins and proteins extracted by acid followed, however, by substantial lowering of the level of these compounds. The proteins obtained by acid extraction are characterized by more explicit changes. This permits assuming their important role in the pathogenesis of hypercholesterinemia. The obtained results make it possible to state that the investigated proteins possess the alkaline properties. The data available in literature on the ability of alkaline polypeptides to bind cholesterol permit assuming that the investigated proteins have the same properties and, hence, can participate in the molecular mechanisms of cholesterol transport as well as in the processes of synthesis and transformations of separate classes of lipoproteins.     

Changes in composition and content of mycolic acids in glutamate-overproducing Corynebacterium glutamicum

Overproduction of glutamate by Corynebacterium glutamicum is induced by biotin limitation or by the supplementation of specific detergents, sublethal amounts of penicillin, or cerulenin. But, it remains unclear why these different treatments, which have different sites of primary action, produce similar effects.In this study, it was found that the cellular content of mycolic acids--characteristic constituents of Corynebacterineae that are synthesized from fatty acids and form a cell surface layer--decreased under all conditions that induced glutamate overproduction. Furthermore, short mycolic acids increased under conditions of biotin limitation and cerulenin supplementation. These results suggest that different treatments produce the same effect that causes defects in the mycolic acid layer. This is perhaps one of the key factors in overproduction of glutamate by C. glutamicum.     

Changes in nucleic acid and protein content in different regions of the brain is rats reared in enriched and impoverished environments

The content of nucleic acids (DNA and RNA) and proteins in 1 mg of tissue and RNA/DNA and protein/DNA ratio in different brain structures (the neocortex, the hippocampus, the cerebellum, the brain-stem), as well as in the liver was studied in rats at different stages of postnatal ontogenesis (25 to 55 days) in the norm, under ecological deprivation and in an information-enriched medium, involving elaboration of conditioned reflexes. It was shown that intense physiological function of the brain cells in an information-enriched medium is attended with substantial enhancement of the RNA/DNA ratio, i.e. stimulation of transcribing activity of the cells genome. In conditions of ecological deprivation this value at first slightly increases, and the significantly diminishes in all the studied brain structures. Protein content in the nerve tissue is more stable in ontogenesis and changes but slightly at different afferentation levels. No significant changes were observed in any of the studied parameters in the lever tissue.     

Changes in the nucleic acid and protein content of the Japanese quail during postnatal development

A study of growth activity in the Japanese quail showed the rate of growth to be the highest, in both sexes, between the ages of 5 and 20 days. Positive allometry was manifested in skeletal muscle development, negative allometry or isometry in the case of the liver and heart. The protein/P DNA ratio rose progressively with age in all the given tissues and attained the maximum prior to sexual maturation. The P RNA/P DNA ratio rose markedly in all the tissues after only a few days and remained high throughout the whole period of development. Growth dynamics in the both sexes followed the same course; the only exception were proteosynthesis indicators, which attained higher values in females, in correlation to their greater body weight.     

Changes in the serum fraction composition of nucleic acids in radiation injuries. Alterations in an early period after gamma-irradiation of rats

The content and fractional composition of nucleic acids of blood serum change after lethal (8 Gy) particularly superlethal (100 Gy) gamma-irradiation of rats. This concerns DNA the content of which increases by 7 times 5 h following 100 Gy irradiation. It has been shown by electrophoresis in 0.85% agarose that a heterogeneous DNA fraction with the molecular weight of (1-15) X 10(6) dalton increases. The analysis of the preparation in the polyacrylamide gel has revealed a DNA fraction that is not found in norm: the fraction possesses the electrophoretic mobility corresponding to that of nucleosome DNA.