Search PubMed⌕ Search

Biomedical subjects

J Kohout

Publications and source records attributed to J Kohout.

At least 55 records · Page 3Linked to original sources
PubMed1978

Experimental neurosis and gastric secretion in dogs.

In four dogs (2 males and 2 females from one litter) with established gastric cannula gastric secretion was studied in control experiments and in induced experimental neurosis. Gastric secretion was stimulated by insulin. We monitored in individual 15 min. portions the amount of gastric juice, total HCl output, output of acid gastric proteinases, mucoproteins and some ions. The gastric juice was dialyzed and freeze dried. 50 mg of the lyophilisate was separated on Sephadex G 100. Macromolecular substances were fractionated into glycoproteins (peak I), acid gastric proteinases (peak II) and glycopeptides and polypeptides (peak III). The ratio of these individual macromolecular substances remainded constant in the same dog in all control experiments. However, there were significant differences between individual animals. Induction of experimental neurosis (by collision of the alimentary and avoidance reflex) gave rise to changes not only in the output of HCl and gastric proteinases, but also in the ratio of macromolecular substances. In the series of observed parameters these changes were of a different nature in males and females.

Animals↗
PubMed1978

Effect of experimental neurosis on the secretion of acid gastric proteinases in dogs.

In experiments on dogs with gastric cannula we proved that the gastric juice, obtained after intravenous injection of insulin, contained after separation of DEAE Sephadex A-50 5--7 proteolytically active fractions. In four dogs of both sexes the ratio and number of individual fractions remained constant in control experiments. However, there were differences between the animals. After induction of experimental neurosis (by the collision of the alimentary and avoidance reflex) all animals showed the same marked changes in the chromatographic patterns of acid proteinases. There was a change not only in the ratio of two larger groups of proteolytically active fractions but also in the total number of all fractions. These changes persisted for 8--10 weeks after induction of experimental neurosis.

Animals↗
PubMed1978

Lower gastric secretion and higher incorporation of orotic acid into liver RNA in rats treated with 5-azacytidine and cycloheximide.

Out of different azapyrimidines tested for their ability to affect metabolism of orotic acid in the liver of rats kept on food only 5-azacytidine resulted in the enhanced incorporation of orotate into liver RNA following 24 hr pretreatment. Similar effect was observed also in cycloheximide-treated animals. No stimulation of orotic acid utilization following 5-azacytidine or cycloheximidine treatment was observed in the liver of starved animals. Both drugs (but not other pyrimidine analogues tested) depressed markedly gastric secretion in rats and caused decreased evacuation of the stomach. The decreased secretion of pepsin and lower gastric acidity resulting in drug-simulated starvation of the treated animals are discussed in relation to the enhanced uptake of orotic acid into liver RNA.

Animals↗
PubMed1977

Inhibitory effect of various cytostatics and cycloheximide on acute experimental pancreatitis in rats.

Cycloheximide, 5-azacytidine, and 4-methoxybenzoyl-beta-bromoarylate (Cytembena) block the development of experimental acute pancreatitis in rats when mediated by the administration of 5% bile solution into the pancreas in vivo. Six hours after drug treatment the pathological changes, evaluated macroscopically or using histological sections of the pancreas, were significantly decreased. The drugs affected the amount of abdominal fluid and lowered its lipase and amylase activity. The known inhibitory mechanism of the active drugs and the possible advantage of cycloheximide for clinical use are briefly mentioned.

Acrylates↗
PubMed1977

Nuclear suppressors of the (poky) cytoplasmic mutant in Neurospora crassa. II. Mitochondrial cytochrome systems.

The mitochondrial cytochrome aa3 and b deficiencies of the [poky] cytoplasmic mutant of Neurospora crassa are partially suppressed by mutant alleles of any one of six nuclear genes, namely sup-1, sup-3, sup-4, sup-5, sup-10 and sup-14. The suppressor-induced increases in the concentration of both cytochromes are detected in the mitochondria from exponentially growing [poky] cultures, and, thus, are clearly distinguishable from the age-dependent changes in the cytochrome system that occur in cultures that approach, or have reached, the stationary phase of growth. The relative amounts of mitochondrial cytochromes aa3 and b show a direct correlation with the relative efficiency of the various sup genes as suppressors of the slow-growth phenotype of [poky]. Since [poky] is defective in mitochondrial protein synthesis due to a lack of 30 S mitochondrial ribosomal subunits, it is proposed that the six suppressors promote the assembly of functional mitochondrial ribosomes.

Alleles↗
PubMed1977

Proof of chymotrypsin activity by a peroral test using a synthetic peptide with a C-terminal P-aminobenzoic acid residue.

The reciprocal relationship between the peroral dose and urinary excretion and the optimum testing load of para-aminobenzoic acid (PABA) and N-acetyl tyrosine peptide (Ac-L-Tyr-PABA), alone and after cholecystokinin-pancreozymin and secretin hormonal stimulation, was studied in rats. Between the peroral test dose of PABA and its urinary excretion there is a constant proportionality which is correlated to the size of the dose and is linear in the dose range up to 50 mg/kg b.w. The situation for Ac-L-Tyr-PABA is similar. Dosage of over 50 mg/kg b.w. do not lead to proportional excretion of the test substance in the urine. I.v. stimulation by cholecystokinin-pancreozymin and secretin, using peroral administration of Ac-L-Tyr-PABA, was not followed by a significant increase in urinary PABA excretion. The optimum peroral load of both PABA and Ac-L Tyr-PABA in the rat is 50 mg/kg b.w. With this dose, 82% of free PABA and 77% of the model peptide PABA excreted in 24 hours is found in the urine after 6 hours, so that for practical purposes this interval is adequate. The findings furnish important information on the possibilities of utilizing the given technique for diagnosing the state of exocrine pancreatic function in clinical practice.

4-Aminobenzoic Acid↗
PubMed1977

Specificity of gastric proteinases.

The aim of our study was to isolate the gastricsin fraction in the purest possible form and to verify some of its properties for further study of the specificity of synthetic substrates. The next step in our research will be a similar analysis of pepsin.

Amino Acids↗