Hostname: page-component-848d4c4894-sjtt6 Total loading time: 0 Render date: 2024-06-17T08:02:05.212Z Has data issue: false hasContentIssue false

Glucose metabolism in shorn and unshorn pregnant sheep

Published online by Cambridge University Press:  09 March 2007

M. E. Symonds
Affiliation:
Department of Physiology & BiochemistryUniversity of Reading, Whiteknights, Reading RG6 2AJ
M. J. Bryant
Affiliation:
Department of Agriculture, University of Reading, Whiteknights, Reading RG6 2AJ
D. A. L. Shepherd
Affiliation:
Department of Physiology & BiochemistryUniversity of Reading, Whiteknights, Reading RG6 2AJ
M. A. Lomax
Affiliation:
Department of Physiology & BiochemistryUniversity of Reading, Whiteknights, Reading RG6 2AJ
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. Whole-body, hind-limb and uterine tissue metabolism of glucose was studied using a combination of isotopic and arterio-venous difference techniques in shorn and unshorn pregnant sheep over the final 4 weeks of pregnancy. This was combined with the measurement of the concentrations of oxygen and carbon dioxide in arterial blood and plasma concentrations of lactate, acetate, non-esterified fatty acids, 3-hydroxybutyrate, glycerol, growth hormone (GH), insulin, glucagon, cortisol, thyroxine and 3, 5, 3'-triiodothyronine (T3).

2. Glucose entry rate was 28 % higher in shorn ewes compared with unshorn controls, even though there was no difference in the arterial plasma concentration of glucose. This effect may have been caused by a decrease in the molar rate, insulin: glucagon (I:G), which was 40% lower in shorn ewes as a result of a significant decrease in the plasma concentration of insulin. There was no difference in the plasma concentration of cortisol or GH.

3. Blood flow across the hind-limb or uterine tissues was not significantly different between shorn and unshorn groups, neither were the net glucose uptake, glucose oxidation rate or contribution of glucose to O2 consumption across these tissues.

4. Insulin-tolerance tests performed on a separate group of shorn and unshorn ewes showed an increased sensitivity to the hypoglycaemic effects of insulin in the shorn group.

5. There was no significant difference between shorn and unshorn animals in the contribution of glucose to CO2 output or in the proportion of glucose entry rate oxidized. CO2 entry rate was 18% higher in shorn ewes compared with unshorn controls which resulted in a 26 % higher estimated value for heat production. There was a 47 % increase in glucose oxidation rate in shorn ewes but there was no significant difference in the proportion of total heat production which was derived from glucose. The arterial concentrations of O2 and CO2 were significantly higher in shorn ewes, which may be an indication of the higher metabolic rate in these animals. This effect may be mediated via a significant rise in plasma T3 concentration in the shorn group.

6. It is concluded that as a result of long-term cold exposure there is a significant increase in whole-body glucose entry and oxidation rates in the shorn pregnant ewe. The increase in insulin sensitivity at the same time as a decrease in plasma insulin concentration may represent a mechanism to ensure continued glucose supply to insulinsensitive tissues while the concomitant decrease in plasma I:G stimulates hepatic gluconeogenesis.

Type
General Nutrition papers
Copyright
Copyright © The Nutrition Society 1988

References

Annison, E. F., Brown, R. E., Leng, R. A., Lindsay, D. B. & West, C. E. (1967). Biochemical Journal 104, 135147.CrossRefGoogle Scholar
Baird, G. D., van der Walt, J. G. & Bergman, E. N. (1983). British Journal of Nutrition 50, 249265.CrossRefGoogle Scholar
Bassett, J. M. (1972). Australian Journal of Biological Sciences 23, 12771287.CrossRefGoogle Scholar
Bell, A. W., Chandler, K. D. & Leury, B. J. (1982). In Energy Metabolism of Farm Animals, European Association for Animal Production Publication no. 29, pp. 5861 [Ekern, A. and Sunstøl, F., editors.] London: Academic Press.Google Scholar
Bromer, W. W. (1972). In Handbook of Physiology, sect. 7, Vol. 1, pp. 133138 [Freinkel, N. and Steiner, D.F., editors]. Washington: American Physiological Society.Google Scholar
Brown, B. W., Oddy, V. H. & Jones, A. W. (1982). Australian Journal of Biological Sciences 35, 2531.CrossRefGoogle Scholar
Chaiybutar, N., Faulkner, A. & Peaker, M. (1982). British Journal of Nutrition 47, 8794.CrossRefGoogle Scholar
Chandler, K. D. & Bell, A. W. (1981). Journal of Developmental Physiology 3, 161176.Google Scholar
Danforth, E. (1983). American Journal of Clinical Nutrition 38, 10061017.CrossRefGoogle Scholar
Faichney, G. J., Barker, P. J., Setchell, B. P. & Lindsay, D. B. (1981). Quarterly Journal of Experimental Physiology 66, 195201.CrossRefGoogle Scholar
Gutmann, I. & Wahlefield, A. W. (1974). In Methods of Enzymatic Analysis, pp. 14641469 [Bergmeyer, H.U. and Gawehn, K., editors]. Weinham: Verlag Chemie.Google Scholar
Hart, I. C., Blake, L. A., Chadwick, M. E., Payne, G. E. & Simmonds, A. D. (1984). Biochemical Journal 218, 573581.CrossRefGoogle Scholar
Hatfield, G. M., Joyce, J., Jeacock, M. K. & Shepherd, D. A. L. (1984). British Journal of Nutrition 52,529543.CrossRefGoogle Scholar
Hay, W. W., Sparks, J. W., Gilbert, M., Battaglia, F. C. & Meschia, G. (1984 a). Journal of Endocrinology 100, 119124.CrossRefGoogle Scholar
Hay, W. W., Sparks, J. W., Wilkening, R. B., Battaglia, F. C. & Meschia, G. (1983). American Journal of Physiology 245, E347E350.Google Scholar
Hay, W. W., Sparks, J. W., Wilkening, R. B., Battaglia, F. C. & Meschia, G. (1984 b). American Journal of Physiology 246, E237E242.Google Scholar
Hinks, N. T., Mills, S. C. & Setchell, B. P. (1966). Analytical Chemistry 17, 551553.Google Scholar
Hodgson, J. C., Mellor, D. J. & Field, A. C. (1980). Biochemical Journal 186, 739747.CrossRefGoogle Scholar
Hodgson, J. C., Mellor, D. J. & Field, A. C. (1981). Biochemical Journal 196, 179186.CrossRefGoogle Scholar
Humbel, R. E., Bossard, H. R. & Zahn, H. (1972). In Handbook of Physiology sect. 7, Vol. 1, pp. 111132 [Freinkel, N. and Steiner, D.F., editors]. Washington: American Physiological Society.Google Scholar
Katz, J., Rostami, H. & Dunn, A. (1974). Biochemical Journal 142,161170.CrossRefGoogle Scholar
McKay, D. G., Young, B. A. & Milligan, L. P. (1974). In Energy Metabolism of Farm Animals, European Association for Animal Production Publication no. 14, pp. 3942 [Menke, K.H., Lantzsech, H. J. and Reichl, J. H., editors]. London: Academic Press.Google Scholar
MacRae, J. C. & Wilson, S. (1978). International Journal of Applied Radiation and Isotopes 29, 191195.CrossRefGoogle Scholar
Oddy, V. H., Brown, B. W. & Jones, A. W. (1981). Australian Journal of Biological Sciences 34, 419425.CrossRefGoogle Scholar
Oddy, V. H., Gooden, J. M. & Annison, E. F. (1984). Australian Journal of Biological Sciences 37,375388.CrossRefGoogle Scholar
Oddy, V. H., Gooden, J. M., Hough, G. H., Teleni, E. & Annison, E. F. (1985). Australian Journal of Biological Sciences 38, 95108.CrossRefGoogle Scholar
Pethick, D. W., Lindsay, D. B., Barker, P. J. and, Northrop, A. J. (1981). British Journal of Nutrition 46, 97109.CrossRefGoogle Scholar
Sasaki, Y., Takahashi, H., Ohenda, H. A. A. & Weekes, T. E. C. (1982). Endocrinology 111, 20702076.CrossRefGoogle Scholar
Snowswell, A. M., Costa, N. D., McLean, J. G., Baird, G. D., Lomax, M. A. & Symonds, H. W. (1978). Journal of Dairy Science 45, 331338.Google Scholar
Somogyi, M. (1945). Journal of Biological Chemistry 160, 6973.CrossRefGoogle Scholar
Steel, J. W. & Leng, R. A. (1973). British Journal of Nutrition 30, 451473.CrossRefGoogle Scholar
Symonds, M. E. (1986). Energy metabolism in the shorn and unshorn pregnant ewe. PhD Thesis, University of Reading.Google Scholar
Symonds, M. E., Bryant, M. J. & Lomax, M. A. (1985). Proceedings of the Nutrition Society 44, 136A.Google Scholar
Symonds, M. E., Bryant, M. J. & Lomax, M. A. (1986 a). British Journal of Nutrition 56, 635643.CrossRefGoogle Scholar
Symonds, M. E., Bryant, M. J., Shepherd, D. A. L. & Lomax, M. A. (1986 b). Proceedings of the Nutrition Society 45, 93A.Google Scholar
Thompson, G. E., Bassett, J. M. & Bell, A. W. (1978 a). British Journal of Nutrition 39, 219226.CrossRefGoogle Scholar
Thompson, G. E., Bassett, J. M., Samson, D. E. & Slee, J. (1982). British Journal of Nutrition 48, 5964.CrossRefGoogle Scholar
Thompson, G. E., Manson, W., Clarke, P. L. & Bell, A. W. (1978 b). Quarterly Journal of Experimental Physiology 63, 189199.CrossRefGoogle Scholar
Weekes, A. J. F., Sasaki, Y. & Tsuda, T. (1983). American Journal of Physiology 244, E335E345.Google Scholar
Wieland, O. (1974). In Methods of Enzymatic Analysis, pp. 14041409 [Bergmeyer, H.U. and Gawehn, K., editors]. Weinham: Verlag Chemie.Google Scholar
Wilson, S. (1984). Canadian Journal of Animal Science 64, Suppl.246247 Abstr.Google Scholar
Wilson, S., MacRae, J. C. & Buttery, P. J. (1981). Research in Veterinary Science 30, 205212.CrossRefGoogle Scholar