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Biomedical subjects

Z Kopec

Publications and source records attributed to Z Kopec.

At least 19 recordsLinked to original sources
PubMed1985

Determination of physiological casein and wheat gluten protein requirements of adult rats aged 75-89 days.

Mounting doses of casein and wheat gluten protein (from 0% to 40% in the diet) were given to adult male rats aged 75-89 days for 14 days. The optimum physiological daily dose, determined from changes in body nitrogen, body water and body weight, was 2.76 g/d for casein protein (corresponding to a 10% casein protein diet) and 3.67 g/d for wheat gluten protein (corresponding to a 15% gluten protein diet). Determined from body weight changes, the daily maintaining dose of casein or wheat gluten protein was 1.054 and 1.511 mg/d respectively, from body nitrogen changes 970 and 1.514 mg/d and from body water changes 1.124 and 1.637 mg/d. Compared with newly weaned animals aged 35-49 days, the optimum physiological daily dietary protein doses for adult animals fall, while the maintaining doses rise.

Animals↗
PubMed1984

Physiological casein and gluten protein requirements of growing rats.

Using mounting casein and wheat gluten protein values (0-40%) in the animals' diet, the optimum and minimum physiological daily doses were determined in 49-day-old growing rats from changes in their body water, body nitrogen and protein intake. The optimum physiological doses were identical with the peak of linearity of the given parameters, which coincided with a 15% casein protein and a 20% gluten protein concentration in the diet. This was also confirmed by the maximum body amino acid values, which were found in animals given a 15% casein or 20% gluten protein diet. It was further confirmed by the finding of significantly elevated alanine aminotransferase and aspartate aminotransferase activity in the liver of animals with a higher intake of the above protein sources. The minimum physiological dose of the given protein was determined from the equations of the regression curves in the presence of zero changes in the body nitrogen or body water content. The optimum physiological daily doses of casein and wheat gluten protein were 3.25 g and 4.05 g respectively. The minimum physiological daily doses of casein protein were 268 mg (from body nitrogen changes) and 371 mg (from body water changes) and the minimum physiological daily doses of gluten protein were 892 mg (from body nitrogen changes) and 1,000 mg (from body water changes). The above indicators demonstrate, in the presence of higher and high dietary concentrations, that an intake of the given proteins over and above the optimum physiological daily dose is at the very least uneconomical (gluten), if not harmful (casein), making this a highly topical problem for further study.

Aging↗
PubMed1982

Adaptability of pancreatic enzymes activity to various food nutritive values in man. Influence of high protein diet.

The effect of varying dietary protein content on the activity of human pancreatic proteinases was studied in healthy volunteers. Following the consumption of food with a higher protein content, proteinases activities in duodenal aspirate after pancreozymin and secretin stimulation showed an increasing trend only for a period of 14 days and then returned to their original values. Chymotrypsin is more sensitive and its activity increased significantly. Trypsin activity increased without statistical significance. No evidence of changing other parameter (volume, bicarbonate concentration, amylase and lipase activities) was observed.

Adult↗
PubMed1982

Minimum and optimum physiological doses of egg albumin and mutton protein in newly weaned rats.

Using diets with a mounting egg albumin and mutton protein concentration, the authors determined the optimum physiological doses, which are identical with the maximum of linearity of the given parameters, from changes in body nitrogen, body weight and body water. The regression equations of the lines from these parameters were used to determine the minimum physiological doses for newly weaned rats. The optimum and minimum physiological doses of the amino acids in the relevant dietary proteins were also determined by analysing the source for its nitrogen content and other components and for the amino acid spectrum. The optimum dose of egg albumin protein for newly weaned rats was 1.69 g/day (on a 15% protein diet) and of mutton protein 2.56 g/day (on a 12.5% protein diet), with daily amounts of 60 mg methionine, 93 mg phenylalanine, 112 mg valine and 60 mg tyrosine for both proteins. The minimum doses of egg albumin and mutton protein, determined from changes in body nitrogen were 282 mg and 213 mg/day respectively [methionine 10.4 (4.7) mg/day, phenylalanine 16.1 (7.5) mg/day, valine 19.1 (9.2) mg/day and tyrosine 9.8 (5.2) mg/day)].

Amino Acids↗
PubMed1976

Adaptation of pancreatic amylase activity to enhanced parenteral carbohydrate intake in rats, and electron microscopic findings.

The present study records a rise of amylase activity in rat pancreatic tissue after a long-term administration of high carbohydrate diets (14% excess of glucose administered orally or subcutaneously as 30% glucose solution) in comparison to a normal diet. It was concluded that the pancreas obtains information on intestinal food composition along the humoral pathway. Electron microscopic investigations revealed no impairment of the acinar cells of the pancreas, but only changes that may be considered as a structural expression of the various phases of activity of the acinar cells.

Adaptation, Physiological↗