Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-25T05:27:03.701Z Has data issue: false hasContentIssue false

The effect of fasting on enzyme levels in the enlarged and involuting rat pancreas

Published online by Cambridge University Press:  09 March 2007

R. A. Crass
Affiliation:
Department of Physiology, University of Western Australia, Nedlands, Western Australia, 6009, Australia
P. S. Oatesa
Affiliation:
Department of Human Biology, Curtin University of Technology, Bentley, Western Australia, 6109, Australia
R. G. H. Morgan
Affiliation:
Department of Physiology, University of Western Australia, Nedlands, Western Australia, 6009, Australia
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

1. The effect on pancreatic digestive enzyme levels of fasting and changes from a diet containing trypsin inhibitor (raw soya-bean flour, RSF) to diets free of trypsin inhibitor (heated soya-bean flour, HSF, or commercial rat chow) was studied in rats for up to 7 d.

2. In RSF-fed rats killed without fasting, enzyme levels were low, but after fasting for 24 h before killing there was a marked increase in all enzyme levels. Histological studies showed that pancreatic acinar cells from RSF-fed rats killed without fasting were devoid of zymogen granules, but following a 24 h fast there was a marked accumulation of zymogen granules which extend into the basal cytoplasm. Fasting either produced no change or a fall in enzyme levels in rats fasted after feeding HSF or chow continuously.

3. If animals fed on RSF were changed to HSF and either fed or fasted for 24 h up to the time of killing there was an increase in amylase (EC 3. 2. 1. 1), trypsin (EC 3. 4. 21. 4), lipase (triacylglycerol lipase; EC 3. 1. 1. 3) and protein 1 d after the change, followed by a fall over the next 6 d to levels similar to those seen in rats fed on HSF continuously.

4. Animals changed from RSF to chow showed similar effects as far as trypsin, lipase and protein were concerned, but amylase rose, to reach the level seen in rats fed on chow continuously (about ten times that seen in soya-bean-fed rats), after 2 d.

5. These results suggest that in the rats fed on RSF, pancreatic enzyme synthesis is rapid but secretion is equally rapid and intracellular enzyme levels are low. When these animals are fasted or changed to a diet free of trypsin inhibitor the rate of secretion falls but the high rate of synthesis continues for at least 24 h and enzymes accumulate in the pancreas. In studies of pancreatic enzyme levels in rats fed on trypsin inhibitor the extent of fasting before killing the animal is therefore an important variable. Such animals should probably not be fasted before study.

Type
General Nutrition papers
Copyright
Copyright © The Nutrition Society 1987

References

REFERENCES

Abbey, B. W., Norton, G. & Neale, R. J. (1979). British Journal of Nutrition 41, 3945.CrossRefGoogle Scholar
Arnesjö, B., Ihse, I., Lundquist, I. & Quist, I. (1973). Scandanavian Journal of Gastroenterology 8, 545554.CrossRefGoogle Scholar
Crass, R. A. (1983). The effects of soya flour diets and azaserine on the growth and function of the rat pancreas. PhD Thesis, University of Western Australia.Google Scholar
Crass, R. A. & Morgan, R. G. H. (1981). International Journal of Vitamin and Nutrition Research 51, 8591.Google Scholar
Crass, R. A. & Morgan, R. G. H. (1982). British Journal of Nutrition 47, 119129.CrossRefGoogle Scholar
Dahlqvist, A. (1962). Scandanavian Journal of Clinical and Laboratory Investigation 14, 145151.CrossRefGoogle Scholar
Fölsch, U. R., Winckler, K. &Wormsley, K. G. (1974). Digestion 11, 161171.CrossRefGoogle Scholar
Fösch, U. R. & Wormsley, K. G. (1974). Scandanavian Journal of Gastroenterology 9, 679683.CrossRefGoogle Scholar
Green, G. M. & Lyman, R. L. (1972). Proceedings of the Society for Experimental Biology and Medicine 140, 612.CrossRefGoogle Scholar
Haines, P. C. &Lyman, R. (1961). Journal of Nutrition 74, 445452.CrossRefGoogle Scholar
Kakade, M. L., Rackis, J. J., McGhee, J. E. & Puski, G. (1974) Cereal Chemistry 51 376382.Google Scholar
Konijn, A. M., Birk, Y. & Guggenheim, K. (1970). Journal of Nutrition 100, 361368.CrossRefGoogle Scholar
Konijn, A. M., Eyal, Z., Birnbaum, D. &Guggenheim, K. (1972). Digestion 6, 330337.CrossRefGoogle Scholar
Louie, D. S., May, D., Miller, P. & Owyang, C. (1986). American Journal of Physiology 250, G252–G259.Google Scholar
Morgan, R. G. H. (1987). Gut (In the Press).Google Scholar
Morisset, J. (1980). Biomedical Research 1, 405409.CrossRefGoogle Scholar
Naim, M., Gertler, A. & Birk, Y. (1982). British Journal of Nutrition 47, 281288.CrossRefGoogle Scholar
Nitsan, Z. & Liener, I. E. (1976). Journal of Nutrition 106, 300305.CrossRefGoogle Scholar
Oates, P. S. & Morgan, R. G. H. (1982). American Journal of Pathology 108, 217224.Google Scholar
Oates, P. S. & Morgan, R. G. H. (1984 a). American Journal of Physiology 247, G457–G462.Google Scholar
Oates, P. S. & Morgan, R. G. H. (1984 b). American Journal of Physiology 247, G667–G673.Google Scholar
Oates, P. S., Morgan, R. G. H. & Light, A. M. (1986). American Journal of Physiology 250, G9–G14.Google Scholar
Petersen, H., Solomon, T. & Grossman, M. I. (1978). American Journal of Physiology 234, E286–E293.Google Scholar
Preiser, H., Schmitz, J., Maestracci, D. & Crane, R. K. (1975). Clinica Chimica Acta 59, 169175.CrossRefGoogle Scholar
Schacterle, G. R. & Pollack, R. L. (1973). Analytical Biochemistry 51, 654655.CrossRefGoogle Scholar
Shihabi, Z. K. & Bishop, C. (1971). Clinical Chemistry 17, 1150&–1153.CrossRefGoogle Scholar
Solomon, T. E., Petersen, H., Elashoff, J. & Grossman, M. I. (1978). American Journal of Physiology 235, E714719.Google Scholar
Temler, R. S., Dormond, C. A.Simon, E., Morel, B. & Mettraux, C. (1984). Journal of Nutrition 114, 270278.CrossRefGoogle Scholar
Verduin, P. A., Punt, J. M. H. M. & Kreutzer, H. H. (1973). Clinica Chimica Acta 46, 1119.CrossRefGoogle Scholar