Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-30T00:51:44.643Z Has data issue: false hasContentIssue false

The maximum capacity of the liver of the adult dairy cow to metabolize ammonia

Published online by Cambridge University Press:  09 March 2007

H. W. Symonds
Affiliation:
Agricultural Research Council, Institute for Research on Animal Diseases, Compton, Newbury, BerkshireRG16 0NN
Denise L. Mather
Affiliation:
Agricultural Research Council, Institute for Research on Animal Diseases, Compton, Newbury, BerkshireRG16 0NN
K. A. Collis
Affiliation:
Agricultural Research Council, Institute for Research on Animal Diseases, Compton, Newbury, BerkshireRG16 0NN
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. Three adult dairy cows were fitted with cannulas in a mesenteric, portal, hepatic and jugular vein and a carotid artery. They received infusions of step-wise increasing amounts of ammonia as ammonium acetate via a mesenteric vein until NH3 intoxication occurred. Sodium acetate was used in control infusions. The maximum rate of uptake of NH3 by the liver and the concentrations of glucose, urea, lactate, acetate and bilirubin in blood were measured.

2. During the infusions of ammonium acetate the liver extracted almost all the NH3 present in the portal vein until an infusion rate of approximately 15·0 mmol/min was reached. The maximum capacity of the liver to remove NH3 during its first pass was on average 1·84 mmol/min per kg wet weight. The cows became intoxicated when arterial plasma ammonia concentrations reached 0·8 mmol/1. Concentrations of NH3 in jugular venous blood were between 66 and 74% of those in the carotid.

Type
General Nutrition
Copyright
Copyright © The Nutrition Society 1981

References

Anderson, D. M. (1969). J. comp. Path. 79, 525.CrossRefGoogle Scholar
Baird, G. D., Symonds, H. W. & Ash, R. (1975). J. agric. Sci., Camb. 85, 281.CrossRefGoogle Scholar
Barej, W., Garwacki, S., Kulasek, G. & Wiechetek, M. (1974). Acta Physiol. Polon. 5, 157.Google Scholar
Barej, W. & Harmeyer, J. (1979). Q. Jl Expl Physiol. 64, 31.CrossRefGoogle Scholar
Beever, D. E., Ulyatt, M. J., Thomson, D. J., Cammell, S. B., Austin, A. R. & Spooner, M. C. (1980). Proc. Nutr. Soc. 39, 66A.Google Scholar
Bergmeyer, H. U. (ed.) (1963). Methods of Enzymic Analysis. New York and London: Academic Press.Google Scholar
Davidovitch, A., Bartley, E. E., Chapman, T. E., Bachtle, R. M., Dayton, A. D. & Frey, R. A. (1977). J. anim. Sci. 44, 702.CrossRefGoogle Scholar
Garwacki, S., Wiechetek, M. & Barej, W. (1979). Q. Jl Expl Physiol. 64, 23.CrossRefGoogle Scholar
Prior, R. L., Clifford, A. J., Gibson, G. E. & Visek, W. J. (1971). Am. J. Physiol. 221, 432.CrossRefGoogle Scholar
Rowlands, G. J., Little, W., Manston, R. & Dew, A. M. (1974). J. agric. Sci., Camb. 83, 27.CrossRefGoogle Scholar
Sigma (1970). Sigma Tech. Bull. No. 970.Google Scholar
Sigma (1978). Sigma Tech. Bull. No. 170-UV.Google Scholar
Snoswell, A. M., Costa, N. D., McLean, J. G., Baird, G. D., Lomax, M. A. & Symonds, H. W. (1978). J. Dairy Sci. 45, 331.Google Scholar
Symonds, H. W. & Baird, G. D. (1973). Res. vet Sci. 14, 267.CrossRefGoogle Scholar
Visek, W. J. (1972). Fedn Proc. Fedn Am. Socs exp. Biol. 31, 1178.Google Scholar