Secretion and protein metabolism in the rat pancreas in vitro

Bauduin, H; Tondeur, T.; Sande, Jacqueline Van; Vincent, D

doi:10.1016/0304-4165(73)90117-7

Cited by 17 publications

(2 citation statements)

References 33 publications

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“…seems to prefer amino acids to D-glucose d s substratc for its energy metabolism. Even if the amino acid uptake is rapid, as ahown by our data as well as others i BCgin and Scholefield 1964), the rapid de-gradation of amino acids might theoretically lead to a competition between secretion and synthesis, since both processes require an adequate supply of energy (Bauduin et al 1973) and the cells also require sufficient intracellular pools of amino acids for protein synthesis. If there is such competition for energy and amino acids, stimulation of one process would predictably lead to inhibition of the other.…”

Section: Discussionsupporting

confidence: 53%

Transport and Oxidation of Amino Acids and Glucose in the Isolated Exocrine Mouse Pancreas: Effects of Insulin and Pancreozymin

Danielsson

Sehlin

1974

Acta Physiologica Scandinavica

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The uptake and oxidation of L‐alanine and L‐leucine as well as the oxidation of D‐glucose were studied in pieces of microdissected exocrine mouse pancreas. The main observations and conclusions were as follows. The rate of oxidation of D‐glucose was low and was only slightly enhanced by increasing its concentration in the medium from 3 to 20 mM. Even at a concentration as low as 0.1 mM, both amino acids were oxidized at a higher rate than D‐glucose. Thus, mouse exocrine pancreas seems to prefer amino acids to D‐glucose as substrate for its energy metabolism. The uptake of L‐alanine and L‐leucine in the exocrine cells was studied with a double‐label technique using 14C‐L‐glucose as an extracellular marker. Both amino acids were rapidly taken up and accumulated in the exocrine cells. D‐glucose inhibited both the uptake and oxidation of L‐alanine. The decreased rate of oxidation of this amino acid might have been due to the reduction in uptake. Stimulation of secretion by cholecystokinin‐pancreozymin increased the oxidation of D‐glucose, L‐alanine and L‐leucine. However, no effect on the transport of the amino acids into the exocrine cells was observed. Therefore the effect of CCK‐PZ on oxidation seems not to depend on an increased uptake of the amino acids. The presence of insulin (100 /

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Section: Discussionsupporting

confidence: 53%

Transport and Oxidation of Amino Acids and Glucose in the Isolated Exocrine Mouse Pancreas: Effects of Insulin and Pancreozymin

Danielsson

Sehlin

1974

Acta Physiologica Scandinavica

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“…In contrast Bauduin et al (24,25) found that while incorporation of L-[4,5-3H]-leucine in vitro into rat pancreas was linear for less than 20 min at a concentration of 26 p M leucine, it was linear for 2 h at a concentration of 0.8 mM. We incubated our minces in the presence of 1 mM leucine.…”

Section: Discussionmentioning

confidence: 64%

DNA and Protein Synthesis in Developing Rat Pancreas

et al. 1987

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ABSTRACT. To define developmental patterns, we determined the rate of protein and DNA synthesis in rat pancreas at birth, 1, 2, 3, 7, 10, 14, 21, 28 days, 2 months, 3 months, and in adults. Fragments of freshly minced pancreas were incubated with [3H]-thymidine and [14Cj-leucine and the DNA and protein synthesis rates were measured. We found that 1) DNA content was lowest at birth, rose through day 3, plateaued at about 8 mg/g wet weight through day 14, then slowly decreased to the adult value of about 5 mg/g at 2 months; 2) protein content, although high at birth, decreased rapidly to a value of 80 mg/g at day 3 and slowly rose to the adult value of 160 mglg; 3) protein synthesis, low at birth, rapidly increased to about five times the adult value by day 3, and remained elevated for the 1st month; 4) DNA synthesis was 15 times the adult rate at birth, increased to 30 times at 3 days of age, then declined slowly in an exponential fashion to the adult value. We conclude that the pancreas at birth is poised biosynthetically to undergo a rapid hyperplastic and hypertrophic response, and this process reaches a maximal rate at about 3 days of age. (Pediatr Res 22: 34-38,1987) Abbreviations MEM, minimum essential medium BSA, bovine serum albumin SA, specific activity PCA, perchloric acid CCK, cholecystokinin Numerous studies have defined the structural and functional development of rodent exocrine pancreas. Similarly, a number of studies has evaluated the effects of various agents thought to be trophic for the exocrine pancreas on DNA and protein content of the developing pancreas. Previous studies, however, have evaluated total DNA and protein content, but not actual rates of synthesis of DNA and protein at various ages (1-5). Since cellular content of biomolecules reflects the opposing actions of synthesis and degradation, the true effects of any agent tested may be masked when total organ content is measured. In addition, increases in DNA synthesis in the stomach and small intestine can be observed before an increase in DNA content itself (6). A further difficulty is that technically it is extremely difficult to remove the entire pancreas from neonatal rats. Accordingly, we have evaluated DNA and protein synthesis in rat pancreas of various ages and compared synthetic rates to those found in the adult animal. Not surprisingly, the synthesis rates of both were found to be considerably higher in the immature animal than in the mature animal. MATERIALS AND METHODSSprague Dawley rats obtained from King Laboratories, Madison, WI were used for all studies and were kept under controlled light and temperature conditions. After birth, the rats were not disturbed except for the addition of food and water. Pups were sacrificed at the stated ages a 2 h for ages up to 72 h, and a 1 day for ages 1 to 4 wk. Adult animals (males only) were 4-6 months old. The date of birth was designated as day 0. Before weaning, rats were not fasted; after weaning (day 21), rats were fasted overnight before sacrifice, but allowed free access t...

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Pathophysiology of the Exocrine Pancreas

Wormsley¹

1976

Pankreas

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Secretion and protein metabolism in the rat pancreas in vitro

Cited by 17 publications

References 33 publications

Transport and Oxidation of Amino Acids and Glucose in the Isolated Exocrine Mouse Pancreas: Effects of Insulin and Pancreozymin

Transport and Oxidation of Amino Acids and Glucose in the Isolated Exocrine Mouse Pancreas: Effects of Insulin and Pancreozymin

DNA and Protein Synthesis in Developing Rat Pancreas

Pathophysiology of the Exocrine Pancreas

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