Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-25T02:40:50.082Z Has data issue: false hasContentIssue false
  • English
  • Français

The validity of assessing changes in intestinal absorption mechanisms for dietary sugars with non-metabolizable analogues (glucalogues)

Published online by Cambridge University Press:  26 February 2008

Gabrielle Syme  and
R. J. Levin
Gabrielle Syme
Affiliation:
Department of Physiology, The University, Sheffield S10 2TN
R. J. Levin
Affiliation:
Department of Physiology, The University, Sheffield S10 2TN
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. Transfer potentials were obtained from everted jejunal sacs prepared from fed euthyroid, fasted euthyroid, fed hypothyroid and fasted hypothyroid rats by addition of serial concentrations of the dietary sugars glucose and galactose and the glucalogues 3-O-methyl glucose, α-methyl glucoside and 6-deoxy-D-glucose to the incubation fluids. The kinetic parameters of ‘apparent Michaelis constant’ (apparent Km) and maximum transfer potential difference (pdmax) obtained from the results were used to characterize the changes in the electrogenic transfer mechanisms for these substrates.

2. Analysis of the significant differential changes in values for ‘apparent Km’ and pdmax for the two dietary sugars and the three glucalogues indicated heterogeneity in the mechanisms for sugar transfer across the intestine and suggested a minimum of four possible carriers.

3. The validity of using glucalogues to characterize changes in the transfer mechanisms for the dietary sugars in different dietary and hormonal states was assessed. None of the kinetic parameters for electrogenic glucalogue transfer matched those for the dietary sugars in all the experimental conditions. The employment of glucalogues to assess changes in electrogenic transfer mechanisms for dietary sugars can thus lead to invalid conclusions.

4. Fasting decreased the ‘apparent Km’ of the dietary sugars and the glucalogues. However, the pdmax values for glucose, galactose, and α-methyl glucoside decreased whereas those for 3-O-methyl glucose and 6-deoxy-D-glucose did not.

5. Hypothyroidism showed different effects in fed and fasted intestine. Because hypothyroidism induced a reduction in food intake, separation of the direct effects of the condition on electrogenic transfer from reduced food intake effects was not possible.

Type
Papers on General Nutrition
Information
British Journal of Nutrition , Volume 43 , Issue 3 , May 1980 , pp. 435 - 443
Copyright
Copyright © The Nutrition Society 1980

References

REFERENCES

Asano, T. (1964). Am. J. Physiol. 207, 415.CrossRefGoogle Scholar
Axelrad, A. D., Lawrence, A. L. & Hazelwood, R. L. (1970). Am. J. Physiol. 219, 860.CrossRefGoogle Scholar
Barnett, J. E. G., Jarvis, W. T. S., Munday, K. A. (1968). Biochem. J. 109, 61.CrossRefGoogle Scholar
Barry, R. J. C., Dikstein, S., Matthews, J., Smyth, D. H. & Wright, E. M. (1964). J. Physiol., Lond. 171, 316.CrossRefGoogle Scholar
Barry, R. J. C. & Eggenton, J. (1972). J. Physiol., Lond. 227, 201.Google Scholar
Berman, W. F., Bautista, J. O., Rogers, S. & Segal, S. (1976). Biochim. biophys. Acta 455, go.Google Scholar
Bronk, J. R. & Parsons, D. S. (1964). Nature, Lond. 201, 712.CrossRefGoogle Scholar
Bronk, J. R. & Parsons, D. S. (1965). J. Physiol., Lond. 179, 323.CrossRefGoogle Scholar
Crane, R. K. (1960). Physiol. Rev. 40, 789.CrossRefGoogle Scholar
Debnam, E. S. & Levin, R. J. (1970). J. Physiol., Lond. 209, 29P.Google Scholar
Debnam, E. S. & Levin, R. J. (1975 a). J. Physiol., Lond. 246, 181.Google Scholar
Debnam, E. S. & Levin, R. J. (1975 b). J. Physiol., Lond. 252, 681.CrossRefGoogle Scholar
Debnam, E. S. & Levin, R. J. (1976). Gut 17, 92.CrossRefGoogle Scholar
Edmonds, C. J., Thompson, B. D. & Marriot, J. (1970). J. Endocr. 48, 189.CrossRefGoogle Scholar
Fisher, R. B. & Parsons, D. S. (1953 a). J. Physiol., Lond. 119, 210.CrossRefGoogle Scholar
Fisher, R. B. & Parsons, D. S. (1953 b). J. Physiol., Lond. 119, 224.CrossRefGoogle Scholar
Geck, P. & Heinz, E. (1976). Biochim. biophys. Acta 443, 49.CrossRefGoogle Scholar
Gelb, A. M. & Chalfin, D. (1967). Clin. Res. 15, 232 (Abstr.).Google Scholar
Halliday, G. J., Howard, R. B. & Munro, A. F. (1962). J. Physiol., Lond. 164, 28P.Google Scholar
Honegger, P. (1973). In Comparative Physiology, p. 41 [Bolis, L., Schmidt-Nielsen, K. and Maddrell, S. H. P., editors]. Amsterdam: North-Holland Publishing Company.Google Scholar
Honegger, P. & Gershon, E. (1974). Biochim. biophys. Acta 352, 127.CrossRefGoogle Scholar
Honegger, P. & Semenza, G. (1973). Biochim. biophys. Acta 318, 390.CrossRefGoogle Scholar
Hopfer, U. (1977). Am. J. Physiol. 233, E445.Google Scholar
Hoshi, T., Suziki, Y., Kusaki, T. & Igarashi, Y. (1976). Tohoku J. exp. Med. 119, 201.CrossRefGoogle Scholar
Ibrahim, K. M. (1978). A study on the effect of unstirred layers and of glycocholate on electrogenic sugar transfer by rat jejunum. MSc Thesis, University of Sheffield.Google Scholar
Krebs, H. A. & Henseleit, K. (1932). Hoppe-Seyler's Z. Physiol. Chem. 210, 33.Google Scholar
Levin, R. J. (1976). In Digestion in the Fowl, p. 63 [Boorman, K. N. and Freeman, B. M., editors]. Edinburgh: British Poultry Science Ltd.Google ScholarPubMed
Levin, R. J., Newey, H. & Smyth, D. H. (1965). J. Physiol., Lond. 177, 58.Google Scholar
Levin, R. J. & Syme, G. (1971). J. Physiol., Lond. 213, 46P.Google Scholar
Levin, R. J. & Syme, G. (1975). J. Physiol., Lond. 245, 271.CrossRefGoogle Scholar
Lyon, I. & Crane, R. K. (1966). Biochim. biophys. Acta 112, 278.CrossRefGoogle Scholar
Lyon, I. & Crane, R. K. (1967). Eiochim. biophys. Acta 135, 61.CrossRefGoogle Scholar
Lyon, I. & Sheerin, H. E. (1971). Biochim. biophys. Acta 249, 1.Google Scholar
Ravis, W. R. & Feldman, S. (1978). J. Pharmac. Sci. 67, 245.CrossRefGoogle Scholar
Read, N. W., Barber, D. C., Levin, R. J. & Holdsworth, C. D. (1977). Gut 18, 865.CrossRefGoogle Scholar
Reiser, S., Michaclis, O., Putney, J. & Hallfrisch, J. (1975). J. Nutr. 105, 894.CrossRefGoogle Scholar
Sepulveda, F. V. & Smith, M. W. (1978). J. Physiol., Lond. 282, 73.Google Scholar
Sokal, R. R. & Rohlf, F. J. (1969). In Biometry, the Principles and Practice of Statistics in Biological Research, p. 224. San Francisco: W. H. Freeman & Co.Google Scholar
Syme, G. & Levin, R. J. (1976). Proc. R. Soc. B 194, 121.Google Scholar
Syme, G. & Levin, R. J. (1977). Biochim. biophys. Acta 464, 620.Google Scholar
Wilson, F. W. & Dietschy, J. M. (1972). J. clin. Invest. 51, 3015.CrossRefGoogle Scholar
Wiseman, G. (1977). J. Physiol., Lond. 273, 731.CrossRefGoogle Scholar