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Urea kinetics of a carnivore, Felis silvestris catus

Published online by Cambridge University Press:  09 March 2007

K. Russell*
Affiliation:
Waltham Centre for Pet Nutrition, Melton Mowbray, LE14 4RT, UK
G. E. Lobley
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen, AB21 9SB, UK
J. Rawlings
Affiliation:
Waltham Centre for Pet Nutrition, Melton Mowbray, LE14 4RT, UK
J. Millward
Affiliation:
School of Biological Sciences, University of Surrey, Guildford, GU2 5XH, UK
E. J. Harper
Affiliation:
Waltham Centre for Pet Nutrition, Melton Mowbray, LE14 4RT, UK
*
*Corresponding author: Ms Kim Russell, fax +44 1664 415 440, email Kim.russell@eu.effem.com
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Abstract

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The effect of two levels of dietary protein energy, moderate (20 %; MP) and high (70 %; HP), on urea kinetics in eleven domestic cats was studied. After a 3-week prefeed, a single dose of [15N15N]urea was administered, and urine and faeces collected over the subsequent 5 d. For each 24 h period, total urea and enrichment of [15N15N]- and [15N14N]urea in urine were determined, and a model applied to calculate urea production, entry into the gastrointestinal tract, recycling to urine or faeces and, by difference, retention by the body and potentially available for anabolism. Urea production and excretion increased with dietary protein level (P<0·05). Most of the urea produced was excreted, with only a small proportion entering the gut, and with the pattern of urea disposal not significantly different between the HP and MP diets. Thus, the percentages of urea production available to the gut were 15 % (MP) and 12 % (HP), of which 57 % (MP) and 59 % (HP) was recycled in the ornithine cycle, 40 % (MP and HP) was potentially available for anabolism and the rest lost as faecal N. As a percentage of urea produced the amount potentially available for anabolism was very low at 6·41 % (MP diet) and 4·79 % (HP diet). In absolute terms urea entering the gut, being recycled in the ornithine cycle and potentially available for anabolism was significantly higher on the HP diet (P<0·05). These results show that cats operate urea turnover, but at a lower rate, and with less nutritional sensitivity than has been reported for other species.

Type
Research Article
Copyright
Copyright © The Nutrition Society 2000

References

Badaloo, A, Boyne, M, Reid, M, Persaud, C, Forrester, T, Millward, DJ and Jackson, AA (1999) Dietary protein, growth and urea kinetics in severely malnourished children and during recovery. Journal of Nutrition 129, 969979.CrossRefGoogle ScholarPubMed
Bundy, R, Persaud, C and Jackson, AA (1993) Measurement of urea kinetics with a single dose of 15N15N urea in free living female vegetarians on their habitual diet. International Journal of Food Sciences and Nutrition 44, 253259.CrossRefGoogle Scholar
Burger, IH, Blaza, SE, Kendall, PT and Smith, PM (1984) The protein requirement of adult cats for maintenance. Feline Practice 14, 814.Google Scholar
Calder, AG and Smith, A (1988) Stable isotope ratio analysis of leucine and ketoisocaproic acid in blood plasma by gas chromatography/mass spectrometry. Use of tertiary butyldimethylsilyl derivatives. Rapid Communications in Mass Spectrometry 2, 1416.CrossRefGoogle ScholarPubMed
Danielsen, M and Jackson, AA (1992) Limits of adaptation to a diet low in protein in normal man: urea kinetics. Clinical Science 83, 103108.CrossRefGoogle ScholarPubMed
Deguchi, E (1985) 15N transfer from 15N urea and 15N diammonium citrate into tissue proteins in normal cats fed with an optimal protein diet. Japanese Journal of Veterinary Science 47, 995998.Google ScholarPubMed
Fau, D, Morris, JG and Rogers, QR (1987) Effects of high dietary methionine on activities of selected enzymes in the liver of kittens (Felis domesticus). Comparative Biochemistry and Physiology 88B, 551555.Google Scholar
Forslund, AH, Hambraeus, L, Olsson, RM, El-Khoury, AE, Yu, Y-M and Young, VR (1998) The 24-h whole body leucine and urea kinetics at normal and high protein intakes with exercise in healthy adults. American Journal of Physiology 275, E310E320.Google ScholarPubMed
Hediger, MA, Smith, CP, You, G, Lee, WS, Kanai, Y and Shayakul, C (1996) Structure, regulation and physiological roles of urea transporters. Kidney International 49, 16151623.CrossRefGoogle ScholarPubMed
Jackson, AA (1983) Amino acids: Essential and non-essential. Lancet i, 10341037.CrossRefGoogle Scholar
Jackson, AA, (1991) Critique of protein-energy interactions in vivo: urea kinetics. In International Dietary Energy Consultancy Group Workshop, Waterville Valley, NH, USA 6779 [Scrimshaw, NS and Schurch, B, editors]. Lausanne, Switzerland: IDECG.Google Scholar
Jackson, AA, Danielsen, M and Boyes, S (1993) A non-invasive method for measuring urea kinetics with a single dose of 15N15Nurea in free living humans. Journal of Nutrition 123, 21292136.Google Scholar
Jackson, AA, Doherty, J, De Benoist, MM, Hibbert, J and Persaud, C (1990) The effect of the level of dietary protein, carbohydrate and fat on urea kinetics in young children during rapid catch-up weight gain. British Journal of Nutrition 64, 371385.CrossRefGoogle ScholarPubMed
Kettlehut, IC, Foss, MC and Migliorini, RH (1980) Glucose homeostasis in a carnivorous animal (cat) and in rats fed a high protein diet. American Journal of Physiology 239, R437R444.Google Scholar
Kornberg, HL and Davies, RE (1952) The metabolism of subcutaneously injected 15N urea in the cat. Biochemistry Journal 52, 345350.CrossRefGoogle Scholar
Langran, M, Moran, BJ, Murphy, JL and Jackson, AA (1992) Adaptation to a diet low in protein: effect of complex carbohydrate upon urea kinetics in normal man. Clinical Science 82, 191198.CrossRefGoogle ScholarPubMed
Marsh, WH, Fingerhut, B and Miller, H (1965) Automated and manual direct methods for the determination of blood urea. Clinical Chemistry 2, 624627.CrossRefGoogle Scholar
Millward, DJ (1995) A protein-stat mechanism for the regulation of growth and maintenance of the lean-body mass. Nutrition Research Reviews 8, 93120.CrossRefGoogle ScholarPubMed
Millward, DJ, Forrester, T, Ah-Sing, E, Yeboah, N, Gibson, N, Badaloo, A, Boyne, M, Reade, M, Persaud, C and Jackson, A (2000) The transfer of 15N from urea to lysine in the human infant. British Journal of Nutrition 83, 505512.CrossRefGoogle ScholarPubMed
Morris, JG and Rogers, QR (1986) Comparative nitrogen nutrition of carnivorous, herbivorous, and omnivorous mammals. Archives of Animal Nutrition 36, 234245.Google ScholarPubMed
National Research Council (1986) In Nutrient Requirements of Cats. Washington, DC: National Academy Press.Google Scholar
Picou, D and Phillips, M (1972) Urea metabolism in malnourished and recovered children receiving a high or low protein diet. American Journal of Clinical Nutrition 25, 12611266.CrossRefGoogle ScholarPubMed
Richards, PA, Metcalfe-Gibson, A, Ward, EE, Wrong, O and Houghton, BJ (1967) Utilisation of ammonia nitrogen for protein synthesis in man, and effect of protein restriction and uraemia. Lancet ii, 845849.CrossRefGoogle Scholar
Rogers, QR, Morris, JG (1980) Why does the cat require a high protein diet? In Nutrition of the Dog and Cat pp. 45-66 [Anderson, R, editor]. Oxford: Pergamon Press.Google Scholar
Rogers, QR, Morris, JG and Freedland, RA (1977) Lack of hepatic enzymatic adaptation to low and high levels of dietary protein in the adult cat. Enzyme 22, 348356.CrossRefGoogle ScholarPubMed
Sarraseca, A, Milne, E, Metcalf, MJ and Lobley, GE (1998) Urea recycling in sheep: effect of intake. British Journal of Nutrition 79, 7988.CrossRefGoogle ScholarPubMed
Schmike, RT (1962) Adaptive characteristics of urea cycle enzymes in the rat. Journal of Biological Chemistry 237, 459468.CrossRefGoogle Scholar
Silva, SVPS and Mercer, JR (1985) Effect of protein intake on amino acid catabolism and gluconeogenesis by isolated hepatocytes from the cat (Felis domestica). Comparative Biochemistry and Physiology 80B, 603607.Google Scholar
Silva, SVPS and Mercer, JR (1991) The effect of protein intake on the potential activity of the lysosomal vacuolar system in the cat. Comparative Biochemistry and Physiology 98A, 551558.Google Scholar
Tanaka, N, Kubo, K, Shiraki, K and Koishi, H (1980) A pilot study on protein metabolism in Papua New Guinea highlanders. Journal of Nutritional Science and Vitaminology 26, 247259.CrossRefGoogle ScholarPubMed
Torrallardona, D, Harris, CI, Coates, ME and Fuller, MF (1996) Microbial amino acid synthesis and utilisation in rats: incorporation of 15N from 15NH4Cl into lysine in the tissues of germ-free and conventional rats. British Journal of Nutrition 76, 689700.CrossRefGoogle ScholarPubMed
Torrallardona, D, Harris, CI, Milne, E, Fuller, MF, (1994) The contribution of intestinal microflora to amino acid requirements in pigs. In Proceedings of VIth International Symposium on Digestive Physiology in pigs. European Association of Animal Production Publication no. 80, pp. 245248.[Souffrant, WB and Hagemeister, H, editors]. Dummerstorf, Germany: Forschungs institut fuer die Biologie landwirtschaftlicher Nutztiere.Google Scholar
Walser, M and Bodenlos, LJ (1959) Urea metabolism in man. Journal of Clinical Investigation 38, 16171626.CrossRefGoogle ScholarPubMed
Waterlow, JC (1999) The mysteries of nitrogen balance. Nutrition Research Reviews 12, 2554.CrossRefGoogle ScholarPubMed