Liver ornithine decarboxylase in pregnant rats fed two levels of casein

1983 ◽  
Vol 244 (6) ◽  
pp. E548-E554
Author(s):  
Y. Hitier ◽  
O. Champigny ◽  
G. Bourdel
Keyword(s):  
Ornithine Decarboxylase ◽  
High Protein Diet ◽  
Tyrosine Aminotransferase ◽  
High Protein ◽  
Protein Diet ◽  
Casein Diet ◽  
Pregnant Rats ◽  
Pregnant Females ◽  
Postprandial Phase ◽  
Different Levels

Liver ornithine decarboxylase (ODC) and tyrosine aminotransferase (TAT) activities were assessed at 2200 h (prandial phase) and at 1000 h (postprandial phase) in virgin and in pregnant (day 13-20) rats fed on different levels of casein and carbohydrate. In virgin rats, ODC levels were higher at 2200 h after resumption of eating than at 1000 hours, the inductive effect being greater with the high-casein than with the low-casein diet. Rapid deinduction followed termination of eating, resulting in equally low enzyme levels at 1000 h with both diets. On the contrary, prandial and postprandial levels of TAT were always greater with the high-protein diet. In pregnant rats, there was a progressive stimulation of ODC that reached a maximum on day 19. However, the inductive capacity of the high-protein diet was lower than that of the low-casein diet. Prandial rest was not followed by enzyme deinduction at 1000 h. In contrast, TAT stimulation remained dependent on overall casein ingestion. At constant casein but restricted carbohydrate intake, pregnant females exhibited a reduction in ODC stimulation. Thus, whereas in virgin females proteins are determinant in the regulation of ODC, during pregnancy there determinant in the regulation of ODC, during pregnancy there is a shift toward modulation by carbohydrates. Levels of liver urea and ornithine were found to vary in inverse proportion with the magnitude of ODC stimulation.

Time Course of Enzyme Adaptation. III. Periodic and Nonperiodic Responses of Rat Liver Enzyme Activities to Diets in Meal-Fed Rats

1971 ◽  
Vol 49 (1) ◽  
pp. 108-118 ◽  
Author(s):  
B. Szepesi ◽  
R. A. Freedland
Keyword(s):  
Pyruvate Kinase ◽  
High Protein Diet ◽  
Periodic Variation ◽  
Maximum Activity ◽  
High Protein ◽  
Protein Diet ◽  
Liver Protein ◽  
Casein Diet ◽  
Phosphohexose Isomerase ◽  
Glucose 6 Phosphate Dehydrogenase

Enzymes associated with carbohydrate and amino acid metabolism as well as other liver constituents were studied in rats meal-fed, daily for 60 min, diets consisting of corn oil, salt, and vitamins plus 75% carbohydrate and 15% casein or a 90% casein diet. Relative liver size and the levels of liver glycogen and total and soluble liver protein were subject to periodic variation after the ingestion of a meal. They reached maximums about 6–12 h after the meal and then declined. In the rats fed the 90% casein diet the onset of increases was delayed after the first meal.The activity of glucose-6-phosphatase was increased by a fructose diet and the high-protein diet, but no periodicity was observed. The activities of fructose-1, 6-diphosphatase, dihydroxyacetone kinase, and malic enzyme were not subject to periodic variation, and these enzymes were not increased by the fructose or high-protein diets. Serine dehydrase activity was increased by the high-protein diet, but the question of periodicity cannot be resolved with the available data.The tyrosine–α-ketoglutarate transaminase activity in rats fed a 75% glucose – 15% casein diet was subject to periodic variation. Maximum activity occurred just before feeding, and minimum activity 12 h after feeding. In the rats fed the 90% casein diet the activity of the enzyme was considerably increased, and was already maximum 3 h after the meal. The activity then decreased to a relatively high minimum 12 h after the meal, at which time it began to increase again.The activities of pyruvate kinase, glucose-6-phosphate dehydrogenase, and phosphohexose isomerase were all subject to periodicity in the glucose-fed rats. In the rats fed the high-protein diet, there was a periodic response in activity of both pyruvate kinase and glucose-6-phosphate dehydrogenase after the first meal; but enzyme activity remained minimum after the second meal. Glucose-6-phosphate dehydrogenase and phosphohexose isomerase activities were increased after three meals of the fructose diet, and were higher than in glucose-fed rats even 24 h after a meal. Maximum activity of these three enzymes occurred 12 h after the meal. There was only small periodicity in the activity of glutamic–pyruvic transaminase. The activity of this enzyme was increased by the high-protein diet and also by the high-fructose diet, although the latter effect was only temporary. The possible importance of certain types of adaptations in meal-fed rats was discussed in connection with physiological requirements.

High Protein Diet and Phenylalanine Hydroxylase Activities in Rats

Pteridines ◽  
1989 ◽  
Vol 1 (4) ◽  
pp. 235-238 ◽  
Author(s):  
Michael P. Carty ◽  
Edel Beirne ◽  
John Donlon
Keyword(s):  
Rat Liver ◽  
Phenylalanine Hydroxylase ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Casein Diet ◽  
Dependent Activity ◽  
Liver And Kidney ◽  
Phenylalanine Metabolism

SummaryThe effects of a diet of 85% casein on the activities of the phenylalanine hydroxylases of rat liver and kidney have been compared. Whereas only the tetrahydrobiopterin-dependent activity of rat hepatic phenylalanine hydroxylase is significantly stimulated, both the tetrahydrobiopterin-dependent and the dimethyltetrahydropterin- dependent activities of the renal enzyme are significantly decreased, after five days of feeding a casein diet. The animals fed a high protein diet for seven days have an increased rate of phenylalanine catabolism in vivo, which is also reflected in increased flux of label from phenylalanine into glucose. The regulation of phenylalanine metabolism, under these conditions, is discussed.

Influence of Environmental and Nutritional Factors on Problem Solving in the Rat

1972 ◽  
Vol 35 (1) ◽  
pp. 235-244 ◽  
Author(s):  
Annie Marie Wells ◽  
Charles R. Geist ◽  
Robert R. Zimmermann
Keyword(s):  
Problem Solving ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Casein Diet ◽  
Nutritional Factors ◽  
Rat Pups ◽  
Low Protein ◽  
Enriched Environments

Rat pups were randomly cross-fostered to lactating dams which were maintained on either 21% casein diet or a 12% casein diet by weight. At 21 days of age the pups fostered with dams receiving 21% casein continued on the high protein diet. The pups fostered with the dams receiving the 12% casein diet were placed either on a low protein diet consisting of 5% casein by weight or on a 21% casein diet provided in restricted amounts in order to maintain their weight equal to that of the animals weaned to the 5% casein diet. Throughout the 8-wk. period in which the dietary regimes were imposed, the pups were housed individually either in spatially, tactually, and visually enriched, or impoverished environments. At 11 wk. of age all of the animals were rehabilitated and maintained on the 21% high protein diet for the remainder of the experiment. When problem-solving ability was measured by performance in the Hebb-Williams maze, the low-protein animals reared in impoverished environments exhibited the greatest latencies to leave the start box, spent the longest time within the maze enclosure, and made the greatest number of errors Conversely, the high-protein animals reared in the enriched environments showed the shortest latencies, spent less time in the maze, and made the fewest errors.

Role of the pancreas in reduction of fecal fat and cholesterol by dietary protein

1960 ◽  
Vol 198 (2) ◽  
pp. 354-356
Author(s):  
L. Fragola ◽  
D. F. Magee
Keyword(s):  
Dietary Protein ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Pancreatic Ducts ◽  
Casein Diet ◽  
Low Protein ◽  
Fecal Fat ◽  
Fecal Cholesterol

Rats with separation of the pancreatic ducts and sham-operated controls were fed 8% and 30% casein diet. The fecal fats were lowered by the high-protein diet in each case. The magnitude of the decrease was not different in the two groups. The experiment was repeated with the addition of 2% cholesterol to the two diets. Both groups of animals while on the high-protein diet had less fecal cholesterol than when on the low-protein regimen.

Luminal dietary protein, not amino acids, induces pancreatic protease via CCK in pancreaticobiliary-diverted rats

2000 ◽  
Vol 278 (6) ◽  
pp. G937-G945 ◽  
Author(s):  
Hiroshi Hara ◽  
Sumika Ohyama ◽  
Tohru Hira
Keyword(s):  
Amino Acids ◽  
Direct Action ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Intestinal Lumen ◽  
Casein Diet ◽  
Acid Diet ◽  
High Amino Acid ◽  
Pancreatic Proteases

We determined whether pancreatic adaptation to a high-protein diet depends on ingested protein in the intestinal lumen and whether such adaptation depends on a CCK or capsaicin-sensitive vagal afferent pathway in pancreaticobiliary-diverted (PBD) rats. Feeding a high-casein (60%) diet but not a high-amino acid diet to PBD rats increased pancreatic trypsin and chymotrypsin activities compared with those after feeding a 25% casein diet. In contrast, feeding both the high-nitrogen diets induced pancreatic hypertrophy in PBD rats. These pancreatic changes by the diets were abolished by treatment with devazepide, a CCK-A receptor antagonist. Protease zymogen mRNA abundance in the PBD rat was not increased by feeding the high-casein diet and was decreased by devazepide. Perivagal capsaicin treatment did not influence the values of any pancreatic variables in PBD rats fed the normal or high-casein diet. We concluded that luminal protein or peptides were responsible for the bile pancreatic juice-independent induction of pancreatic proteases on feeding a high-protein diet. The induction was found to be dependent on the direct action of CCK on the pancreas. Pancreatic growth induced by high-protein feeding in PBD rats may depend at least partly on absorbed amino acids.

scholarly journals In rats fed a high protein diet, almost half of the carbon skeletons derived from dietary amino acid deamination are not oxidized during the postprandial phase

2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Claire Gaudichon ◽  
Dalila Azzout‐Marniche ◽  
Catherine Luengo ◽  
Sophie Dare ◽  
Patrick Even ◽  
...  
Keyword(s):  
Amino Acid ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Postprandial Phase ◽  
Dietary Amino Acid

scholarly journals A high-protein diet increases faecal IgA concentrations in baby pigs

2008 ◽  
Vol 67 (OCE5) ◽  
Author(s):  
F. Vitari ◽  
A. Morise ◽  
M. Formal ◽  
C. Garcia ◽  
K. Mace ◽  
...  
Keyword(s):  
High Protein Diet ◽  
High Protein ◽  
Protein Diet
Sign in / Sign up

Export Citation Format

Share Document