Renal and salivary clearance of purine derivatives in sheep

AbstractFour adult ewes (mean weight 42·6 kg) fitted with oesophageal fistulae were given 5 mmol/day ofallantoin or saline solutions by intrajugular continuous infusion. The experiment was a randomized cross-over design, with two consecutive 3-day infusion periods. One kg/day fresh matter of either chopped or pelleted fescue hay was distributed over 12 meals and salivary flow estimated from dilution of Co-EDTA infused into the buccal cavity. Allantoin infusion resulted in a rapid increase in its plasma concentration (84 to 128 (s.e. 1·5) μmol/l) and urinary excretion (9·6 to 13·3 (s.e. 0·18) mmol/day) without significant differences between diets. Salivary allantoin also increased (4·6 to 6·4 (s.e. 0·60) ymol/1) in response to infusion, although the concentration of total purine derivatives in saliva was only proportionately 0·08 that of plasma. Renal and salivary clearance of oxypurines, allantoin (78 (s.e. 5·0) ml/min and 13 (s.e. 0·7) ml/h), uric acid (466 (s.e. 98·0) ml/min and 45 (s.e. 9·8) ml/h) and creatinine (104 (s.e. 3·0) ml/min and 14 (s.e. 1·1) ml/h) were constant, irrespective of diet and infusion treatments. Urinary recovery of infused allantoin averaged 0·78 (s.e. 0·031) but salivary secretion, equivalent to about 0·003 of urinary losses, was not the explanation for the incomplete recovery.

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Effect of hindgut fermentation on urinary excretion of purine derivatives

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600026532 ◽

1994 ◽

Vol 1994 ◽

pp. 106-106

Author(s):

J.E.C. Surra ◽

J.A. Guada ◽

J. Balcells ◽

C. Castrillo

Keyword(s):

Uric Acid ◽

Urinary Excretion ◽

Continuous Infusion ◽

Saline Solution ◽

Salivary Secretion ◽

Microbial Production ◽

Purine Derivatives ◽

Urinary Recovery ◽

Alfalfa Hay ◽

Potential Losses

Urinary excretion of allantoin or total purine derivatives (PD) may constitute a valuable index of rumen microbial production in sheep (Chen et al.1990; Balcells et al. 1991) provided the urinary recovery of absorbed purines is constant. Purine losses through saliva account for less than 10 % of the non-urinary losses as suggested by the low salivary concentrations of allantoin and uric acid (Surra et al. 1993). In addition to salivary secretion, a significant amount of blood PD may be directly excreted into the gut, as suggested by the fate of the uric acid and guanine infused, respectively, into the blood of humans (Sorensen, 1960) and pigs (Simmonds et al.1973). However little is known about these potential losses in ruminants and how they might be affected by variations in intestinal fermentation consequent to the site of digestion promoted by different feeding conditions.The aim of this experiment was to elucidate wether variations in hindgut fermentation may affect the urinary excretion of purine derivatives.The experiment was performed on four adult Rasa Aragonesa ewes (35 ±0.4 kg) fitted with permanent catheters in both duodenum and caecum and receiving 700 g DM/d of alfalfa hay. Treatments attempted to induce variations in hindgut fermentation and PD concentration and consisted in a continuous infusion (2 l/d) of saline solution as control or either 3 g/d of RNA, 100 g/d of starch, or 200 g/d of cellulose dissolved in water up to 21. All infusates were given via caecum in a complete randomized cross over design, except cellulose which was infused into the duodenum due to frequent clogging of the caecal catheter.

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Salivary losses of purine derivatives in sheep

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600024983 ◽

1993 ◽

Vol 1993 ◽

pp. 176-176

Author(s):

J. Surra ◽

J.A. Guada ◽

J. Balcells ◽

C. Castrillo

Keyword(s):

Uric Acid ◽

Urinary Excretion ◽

Salivary Secretion ◽

Purine Derivatives ◽

Preliminary Results ◽

Ruminal Degradation ◽

Saliva Flow

Developed models to estimate rumen microbial yield from the urinary excretion of purine derivatives fail to account for a complete absorbed purines (Chen et al., 1990a, Balcells et al., 1991). Ruminal degradation of purine derivatives recycled via saliva has been suggested as a possible explanation after detecting the presence of allantoin and uric acid in the sheep saliva (Chen et al. 1990b). However, it is not known to what extent these losses may be affected by dietary induced variations in saliva flow (Kay, 1966).This paper reports preliminary results of an experiment designed to study the effect of diet processing and blood allantoin concentration on the rate of purine derivatives losses through salivary secretion.

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Urinary excretion of allantoin and allantoin precursors by sheep after different rates of purine infusion into the duodenum

The Journal of Agricultural Science ◽

10.1017/s002185960007773x ◽

1991 ◽

Vol 116 (2) ◽

pp. 309-317 ◽

Cited By ~ 106

Author(s):

J. Balcells ◽

J. A. Guada ◽

C. Castrillo ◽

J. Gasa

Keyword(s):

Uric Acid ◽

Urinary Excretion ◽

Purine Derivatives ◽

Urinary Recovery ◽

Purine Derivative ◽

Purine Bases ◽

Proximal Duodenum ◽

Maintenance Requirements ◽

The Relationship ◽

Energy Maintenance

SUMMARYTwo experiments were carried out to determine endogenous losses and the response of urinary purine derivatives to increased duodenal inputs of purine bases. Four ewes each fitted with a re-entrant cannula at the proximal duodenum, and conventionally fed, were subjected to full replacement of duodenal digesta followed by the administration of a solution either free of purines (Expt 1) or enriched with increasing amounts of purines, to supply 0·48–21·27 mmol/animal per day (Expt 2). Basal daily urinary excretions of allantoin, uric acid, hypoxanthine and xanthine were 11·5 ± 0·94, 9·9 ± 0·67, 6·9 ± 0·46 and 1·2 ±0·16 mg/kg W0·75. Allantoin was the only purine derivative which increased in response to incremental inputs of duodenal purines. The relationship between allantoin excretion and infused purines showed a urinary recovery of 0·8 for purines infused at > 220 μmol/kg W0·76. Lower rates of infusion did not alter allantoin excretion. The results show urinary allantoin to be a useful index to estimate duodenal input of purines when animals are fed close to or above their energy maintenance requirements.

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Urinary recovery of allantoin in normally fed steers

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200597324 ◽

1998 ◽

Vol 1998 ◽

pp. 80-80

Author(s):

F. Herrera Gomez ◽

F. D. Deb Hovell ◽

C. A. Sandoval Castro

Keyword(s):

Urinary Excretion ◽

Recovery Factor ◽

Purine Derivatives ◽

Urinary Recovery ◽

Host Animal ◽

N Supply ◽

Normal Feeding ◽

The Relationship ◽

Infusion Technique ◽

Microbial N

Studies in the use of the purine derivatives technique in ruminants have been stimulated by the possible use of this technique as an estimator of the rumen microbial-N supplied to the host animal. The recovery factor influences the estimation of the total purines absorbed and therefore the microbial-N supply. The relationship between exogenous purine input and urinary excretion and recovery has been studied using cattle maintained with the intragastric infusion technique (Orskov et al., 1979). The urinary recovery of exogenous purines has been estimated to be 0.77-0.85 (Chen et al., 1990a, Verbic et al., 1990), and this relationship has been assumed to be applicable to normal feeding situations. To our knowledge there is no data to support or reject this approach. This study examined the urinary recovery of exogenous allantoin input in steers under normal feeding conditions.

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Urinary recovery of allantoin in normally fed steers

Proceedings of the British Society of Animal Science ◽

10.1017/s0308229600032931 ◽

1998 ◽

Vol 1998 ◽

pp. 80-80

Author(s):

F. Herrera Gomez ◽

F. D. Deb Hovell ◽

C. A. Sandoval Castro

Keyword(s):

Urinary Excretion ◽

Recovery Factor ◽

Purine Derivatives ◽

Urinary Recovery ◽

Host Animal ◽

N Supply ◽

Normal Feeding ◽

The Relationship ◽

Infusion Technique ◽

Microbial N

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Basal urinary excretion of purine derivatives in sheep

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600018900 ◽

1990 ◽

Vol 1990 ◽

pp. 109-109 ◽

Cited By ~ 1

Author(s):

J. Balcells ◽

J.A. Guada ◽

C. Castrillo ◽

J.I. Bonafonte

Keyword(s):

Uric Acid ◽

Nucleic Acids ◽

Urinary Excretion ◽

Purine Derivatives ◽

Exogenous Supply

In ruminants duodenal purines,mainly derived from microbial nucleic acids, are catabolised and excreted in the urine as xanthine, hypoxanthine, uric acid and allantoin. The use of purine derivatives as an index of net microbial syntesis in the rumen requires a better understanding of the contribution of endogenus losses to total urinary excretion.Similar levels of basal excretion of purine derivatives has been determined in ruminants maintained by intragastric nutrition (Giesecke et al. 1984, Fujihara et al. 1987) and preruminants fed on liquid diets (Linberg, 1989). However, lower excretion of allantoin and uric acid were recorded when exogenous supply was reduced by fasting (Rys et al. 1975).

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Effect of amino acids on the plasma concentration and urinary excretion of uric acid and uridine

Metabolism ◽

10.1016/s0026-0495(99)90200-7 ◽

1999 ◽

Vol 48 (8) ◽

pp. 1023-1027 ◽

Cited By ~ 10

Author(s):

Tetsuya Yamamoto ◽

Yuji Moriwaki ◽

Sumio Takahashi ◽

Zenta Tsutsumi ◽

Hiroyuki Ohata ◽

...

Keyword(s):

Amino Acids ◽

Uric Acid ◽

Plasma Concentration ◽

Urinary Excretion

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Excretion of purine derivatives by ruminants: recycling of allantoin into the rumen via saliva and its fate in the gut

British Journal Of Nutrition ◽

10.1079/bjn19900107 ◽

1990 ◽

Vol 63 (2) ◽

pp. 197-205 ◽

Cited By ~ 29

Author(s):

X. B. Chen ◽

F. D. DeB. Hovell ◽

E. R. ØRskov

Keyword(s):

Fatty Acids ◽

Uric Acid ◽

Urinary Excretion ◽

Volatile Fatty Acids ◽

Rumen Fluid ◽

Purine Derivatives ◽

Complete Destruction ◽

Series Of Experiments ◽

Micro Organisms

The saliva of sheep was shown to contain significant concentrations of uric acid (16 (sd) 4.5) μmol/l) and allantoin (120 (sd 16.4) μmol/l), sufficient to recycle purine derivatives equivalent to about 0.10 of the normal urinary excretion. When allantoin was incubated in vitro in rumen fluid, it was degraded at a rate sufficient to ensure complete destruction of recycled allantoin. In a series of experiments in which allantoin was infused into the rumen of sheep fed normally, or into the rumen or abomasum of sheep and the rumen of cattle completely nourished by intragastric infusion of volatile fatty acids and casein, no additional allantoin was recovered in the urine. These losses were probably due to the degradation of allantoin by micro-organisms associated with the digestive tract. It is concluded that all allantoin and uric acid recycled to the rumen via saliva will be similarly degraded. Therefore, the use of urinary excretion of purine derivatives as an estimator of the rumen microbial biomass available to ruminants will need to be corrected for such losses.

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Response of urinary and plasma purine derivatives to various rates and infusion patterns of purines in sheep nourished by intragastric infusion

The Journal of Agricultural Science ◽

10.1017/s0021859697004589 ◽

1997 ◽

Vol 129 (3) ◽

pp. 343-352 ◽

Cited By ~ 16

Author(s):

X. B. CHEN ◽

T. FUJIHARA ◽

K. NAKAMURA ◽

P. O. MAWUENYEGAH ◽

M. F. FRANKLIN ◽

...

Keyword(s):

Plasma Concentration ◽

Urinary Excretion ◽

No Value ◽

Volatile Fatty Acids ◽

Estimated Glomerular Filtration Rate ◽

Lag Time ◽

Purine Derivatives ◽

Entry Rate ◽

Abomasal Infusion ◽

Tubular Transport

The effects of exogenous purine supply on plasma concentration and urinary excretion of purine derivatives (PD), which include allantoin, uric acid, xanthine and hypoxanthine, were studied. Five sheep, totally nourished by intragastric infusion of volatile fatty acids and casein, were given an abomasal infusion of a mixture of adenosine and guanosine at three levels (5·0, 10·0 and 20·0 mmol/day) each in four infusion patterns (as one, two, or four 3-h infusion periods per day or infused continuously, P1 to P4 respectively). Urine was collected hourly over 24 h, and plasma samples were collected hourly for 7 h from the start of purine infusion. Both the plasma concentration of PD and its urinary excretion changed rapidly in response to the start and termination of purine infusion with a lag time of 2–3 h. Individual sheep differed considerably in the relative proportions of the different purine derivatives in the urine. The endogenous urinary PD excretion averaged 176 (±S.E. 28) μmol/kg W0·75 per day. Daily PD excretion in urine increased with the amount of purine infusion, but at each level the output decreased significantly in a gradient from P1 to P4. The response of total PD excretion (Y, mmol/day) to daily purine input (X, mmol/day) was predictable and followed the equation: Y=0·81 (±0·02)X+3·07(±0·81) × (u e−0·27X/u +1−u), where u is the duration over which the daily input was infused expressed as a proportion of 24 h. The recovery of the infused purines averaged 81%. When the infusion was given continuously, plasma PD concentration was relatively stable and was linearly correlated with the purine entry rate and daily PD excretion in the urine. The estimated glomerular filtration rate was 150 (±S.E. 16) litres/day and the estimated tubular transport maximum was 2·6 (±S.E. 1·3) mmol/day. It is concluded that due to the rapidity in the response of plasma and urinary PD to changes in the exogenous purine supply, spot measurements of PD in urine or plasma can be of no value for the estimation of exogenous purine uptake unless the purine supply is relatively constant throughout the day. Daily PD excretion in urine related to the exogenous purine uptake in a predictable and reproduceable manner and provides a reliable index for the estimation of the exogenous purine uptake.

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