Search PubMed⌕ Search

Biomedical subjects

E Ia Stan

Publications and source records attributed to E Ia Stan.

34 records · Page 2Linked to original sources
PubMedDate not supplied

[Effect of component 5 of the proteose-peptone fraction of milk on blood circulation indices].

Under study was the influence exerted by peroral administration of component 5 of the proteosoic-peptone milk fraction on the pulse rate, arterial pressure and cerebral circulation in dogs with the subcutaneously exteriorized carotid and under a functional load on the central nervous system (with photostimulation used as a load). The resulting data on the slowing down of the cardiac contractions rhythm and diminished reaction on the level of the minimum pressure and the stroke volume of the cerebral blood flow in response to the functional load testify to a certain regulating effect exerted by component 5 on the circulation, when the central nervous system is subjected to a functional load.

Animals↗
PubMedDate not supplied

[Trypsin and chymotrypsin activity during early postnatal development in the rat].

Activities of trypsin and chymotrypsin were studied in pancreas as well as in chyme from three departments of small intestine of rats of various age. Distinct decrease in content of chymotrypsinogen and increase in content of trypsinogen were observed in pancreas at first four days of rat life. In pancreas content of trypsinogen and chymotrypsinogen was as high in 4--20 days old rats as that one in 30-days old animals, maintained at definitive diet. Activity of trypsin and chymotrypsin was the same in duodenal contents of rats of both these groups. Activity of pancreatic proteinases was almost unaltered in chyme of jejunum intestine within first 20 days of life; it was twice increased to 30-days age. Trypsin and chymotrypsin were distinctly activated in chyme of ileum intestine with ageing. The highest activity of pancreatic proteinases was observed in chyme of ileum intestine. The data obtained suggest that rather intensive cavitary digestion of milk protein occurs in newborn rats.

Animals↗
PubMedDate not supplied

[Physiological activity of kappa-casein glycomacropeptide].

Low molecular peptide fragment [molecular weight 700-2,000] was isolated from the preparation of k-caseine glycomacropeptide using gel chromotography on Sephadex G-25 superfine. After intravenous administration the peptide inhibited gastric secretion more distinctly as compared with the initial preparation. The data obtained suggest that the inhibitory effect of glycomacropeptide was caused by fragment but not by the whole molecule.

Animals↗
PubMedDate not supplied

[Heterogeneity of the kappa-casein glycomacropeptide and physiological activity of its fractions].

A number of fractions with differing intensity of the inhibitory action on the gastric secretion were obtained by gel filtration in a column with biogels P-30 and P-2 of cappa-casein glycomacropeptide. A low-molecular fraction displays the greatest capacity for inhibiting gastric secretion. Desialism, heating and partial hydrolysis of glycomacropeptide with pepsin, trypsin and chemotrypsin used separately have no effect on its inhibitory activity. The resulting data suggest that the inhibitory action of glycomacropeptide is caused by a certain part rather than by entire molecule.

Animals↗
PubMedDate not supplied

[Proteolytic activity of the rat stomach in early ontogenesis during artificial feeding with milk substitutes].

Artificial feeding of new born rats, using milk substitutes containing proteins of rat and cow milk, led to 2-5-fold increase in the total proteolytic activity of stomach contents. In this case proteinases exhibiting pH optima at highly acidic pH were mainly activated. Proteolytic activity exhibiting an optimum at pH 8.0 was found in stomach contents of all the animals studied but it was the most distinct in the experimental group. By means of gel filtration the low molecular products of proteolysis were found in stomach contents; their concentration was 2-fold higher in the new born rats maintained on a diet including cow milk proteins.

Animals↗
PubMedDate not supplied

[Experimental study of the effect of a milk substitute on the secretory activity of the stomach in young rats].

Experiments were made on rats kept on artificial feeding. The animals were divided into two groups. The first group received a milk substitute from the 15th to the 21st day of life. The milk substitute was a liquid diet similar to the composition of rat's milk as regards the main indicators, containing 10% of protein represented by a mixture of casecyte and cow's milk serum proteins. The second group received the substitute once on the 21st day of life. Artificial feeding was shown to lead to a decrease in the pH of gastric chyme and to a rise of the total acidity calculated per mg protein of the chyme as compared to the respective indicators in animals on breast feeding (the third group). As compared to the third group animals, the concentration of pepsin in the gastric chyme increased 5- and 3.5-fold in the first and second group animals, respectively.

Animal Population Groups↗
PubMedDate not supplied

[Glycopeptide obtained from k-casein and its effect on protein assimilation].

The products of restricted proteolysis of kappa-casein were separated by gel filtration. Intravenous injection of high- and low-molecular fractions substantially reduced the pentagastrin-stimulated acid secretion in the anesthetized rat stomach. Intermediate fractions had lesser physiological activity. One of the active fractions administered intraintestinally inhibited acid secretion and reduced the pentagastrin-stimulated secretion in rat weanling isolated stomach. All the active fractions inhibited the stimulated secretion in rats with a ligated vagus. It is concluded that the nervous system does not play a crucial role in the mechanism by which gastric acid secretion is inhibited by the products of restricted proteolysis of kappa-casein. Decreasing acid secretion in the stomach, glycopeptide provides for the conditions favouring the efficacy of protein utilization at an early age. It is suggested that the effect of glycopeptide obtained from kappa-casein on the process of assimilation is mediated via peptide hormones.

Animals↗
PubMedDate not supplied

[Digestive characteristics of qualitatively different proteins in rats in the early postnatal development period].

Starting from 15 days of age the rats were transferred to formula feeding with liquid diet adapted to the rat milk composition in terms of the main parameters. It was shown that caseine exclusion from the rat diet during the early postnatal period of the development and its replacement by proteins of milk serum or by bovine serum albumin that are not capable of curdling leads to a 2- and 3-fold increase, respectively in the protein evacuation rate from the stomach. As a result, the nitrogen content in the chyme of the small intestine rises. One may think that observed accumulation of protein proteolysis products indicates both considerable intensity of cavitary digestion of proteins qualitatively different from caseine in the small intestine of rats in the early postnatal period of the development and its functional overloading as a result of which the protein proteolysis products formed fail to be absorbed.

Animals↗
PubMedDate not supplied

[Digestion of incoagulable proteins during the early postnatal period of development].

Substitution of casein by proteins of milk serum or by bovine blood serum albumin in the diet of 15 days old rats, maintained on artificial food, led to a 2-3-fold increase in the rate of transport of alimentary protein from stomach and to a corresponding elevation in content of nitrogen containing material in chymus of the small intestine. Distinct activation of trypsin and chymotrypsin as well as an increase in concentration of low molecular products of the protein proteolysis were found in the chymus of small intestine.

Adaptation, Physiological↗