scholarly journals The urinary excretion of aromatic acids by starved sheep

1969 ◽  
Vol 23 (3) ◽  
pp. 715-725 ◽  
Author(s):  
A. A. Martin

1. Four wether sheep were maintained on a diet of hay for 2 weeks and then starved for a period of 4 days.2. Immediately before and during starvation the urinary excretion in the following fractions was determined: hippuric acid, creatinine, total diethyl ether-soluble acids of hydrolysed and unhydrolysed urine, total aromatic acids in hydrolysed and unhydrolysed urine and the proportion of the former present as benzoic and phenylacetic acids.3. A method for determining the benzoic acid content of light petroleum extracts of urine has been developed and is described.4. Starvation had little effect on the urinary excretion of phenylacetic acid or creatinine, but during the first 2 days of starvation there were large decreases in the excretion of all the other urinary fractions studied.5. Of the fractions examined, 43% of the diethyl ether-soluble acids of hydrolysed urine and 42% of those of unhydrolysed urine were of exogenous origin; 76% of the total urinary aromatic acids were of exogenous origin. Partition of the aromatic acids in the urine of two of the four sheep indicated that the reduction in aromatic acid excretion on starvation was completely accounted for by the decline in benzoic acid output. Almost all the hippuric acid (97%) was of exogenous origin.6. These results have been compared with the urinary output of aromatic acids by nonruminants when fasted, and possible reasons for the relatively large amounts of phenylacetic acid found in the urine of starved sheep have been discussed.

1970 ◽  
Vol 24 (4) ◽  
pp. 943-959 ◽  
Author(s):  
A. K. Martin

1. S 24 perennial ryegrass was harvested at six stages of its growth from young leafy herbage to mature grass in which the seed had shed.2. Two sheep were offered 1kg/d of each cut and two other sheep were offered 750 g/d of each cut of grass.3. The contents of some possible precursors of the urinary aromatic acids excreted by sheep, namely, shikimic acid, quinic acid, chlorogenic acid, total o-dihydroxyphenolic compounds, lignin and crude protein were determined in each cut of grass.4. A gas-liquid chromatographic method for the determination of the aromatic acids present in light petroleum extracts of urine was developed.5. The urinary excretion of creatinine, diethyl ether-soluble acids, hippuric acid, total benzoic, phenylacetic and phenylpropionic acids, and the apparent digestibilities of nitrogen, lignin and dry matter were determined with each sheep offered each cut of grass.6. The quantity of the various aromatic acid fractions excreted by sheep decreased as the maturity of the herbage increased and was directly proportional to the amount of food consumed.7. No relationship was found between the intake of possible benzoic acid precursors and the urinary excretion of benzoic acid. With diets of young herbage, smaller amounts of benzoic acid were excreted in the urine than would be predicted from the intakes of the precursors studied, and with mature herbage greater amounts were excreted than would be predicted.8. Possible reasons for these results are discussed, and the nature of additional precursors of urinary aromatic acids excreted by sheep given mature herbages are considered.9. Urinary excretion of phenylacetic acid varied with diet in a manner which closely followed the intake of apparently digestible nitrogen. A highly significant (P < 0.001) exponential relationship was found between these two variables; it was log10 E = 0.05 N –0.63, where E is the urinary phenylacetic acid output (g/kg food) and N the intake of apparently digestible nitrogen (g/kg food).


1973 ◽  
Vol 30 (2) ◽  
pp. 251-267 ◽  
Author(s):  
A. K. Martin

1. Two adult wether sheep were maintained on a diet of hay and two on a diet of dried grass for 3 weeks before starvation for a period of 10 d. Urinary excretion of the following acids was determined when the animals were fed and when they were fasted: total diethyl ethersoluble acids of hydrolysed and unhydrolysed urine, hippuric acid, benzoic acid and phenylacetic acid. By the 5th day of fasting, urinary output of all acids had attained stable levels that did not change during the remaining starvation period. The output of all urine fractions except phenylacetic acid declined rapidly during the first 4 d of fasting: phenylacetic acid output by all sheep increased to a maximum during the first 4 d of fast and then declined to stable values (0·42–0·73 g/24 h) which were greater than those observed when the sheep were fed. It is concluded that prolonged retention of food and microbial residues in the digestive tract is responsible for the large output of phenylacetic acid in the urine of fasted sheep.2. Solutions of casein which supplied between 6·3. and 26·5 g nitrogen/24 h were infused into the rumens (fifteen experiments) or abomasums (sixteen experiments) of eight adult wether sheep. Ruminal infusions of casein caused increments in the urinary excretion of diethyl ethersoluble acids and phenylacetic acid. Both these increments were described by linear regression equations (P < 0·001), the coefficients of which showed that 284 ± 44 and 220 ± 21 mg benzoic acid equivalent were excreted as diethyl ether-soluble acids and phenylacetic acid respectively per g casein N infused. The phenylacetic acid excreted was equivalent to 95% of the phenylalanine of the infused casein. No increments in urinary benzoic acid were observed. One sheep scoured when it was given an abomasal infusion of casein. This was the only animal to show any increment in urinary aromatic acids when casein was infused into the abomasum.3. When four sheep were given two rations containing an excess of carbohydrate as sugarbeet pulp or rolled barley, 11 and 16% respectively of their phenylalanine intakes were excreted in the urine as phenylacetic acid. When the same sheep were given two rations containing an excess of N as linseed meal or field beans, 51 and 59% respectively of their phenylalanine intakes appeared in the urine as phenylacetic acid.4. Methods for the determination of creatinine, and of benzoic, phenylacetic, 3-phenylpropionic, cinnamic, hippuric and phenaceturic acids are described.5. It is suggested that the amount of phenylacetic acid excreted in the urine is a measure of the equilibrium occurring in the rumen between catabolism of phenylalanine and reutilization of the products of catabolism for phenylalanine synthesis.


1982 ◽  
Vol 47 (1) ◽  
pp. 139-154 ◽  
Author(s):  
A. K. Martin

1. The contribution of dietary constituents to the large urinary output of benzoic acid characteristic of ruminants and some herbivores is not well understood.2. Methods for the analysis of quinic, cyclohexanecarboxylic, benzoic, phenylacetic, 3-phenylpropionic and cinnamic acids in urine and in rumen fluids were developed.3. The urinary output of aromatic acids by sheep given seven rations was determined: benzoic acid output varied between 2·8 and 7·8 g/d; phenylacetic acid output between 0·16 and 1·3 g/d; cinnamic acid between 0·08 and 0·25 g/d and small amounts of 3-phenylpropionic acid were found in some samples.4. Increments in urinary aromatic acid excretion were determined when the acids listed in paragraph 2 were infused via rumen or abomasal cannulas.5. When cyclohexanecarboxylic acid was infused 40% of the dose was excreted as urinary benzoic acid after either route of infusion. Quinic acid was completely metabolized in the rumen: following rumen infusion between 16 and 53% of the infused acid was recovered as urinary benzoic acid; none was so recovered after abomasal infusion.6. Urinary recoveries of rumen- and abomasally-infused aromatic acids were: benzoic acid 90 and 88% respectively as benzoic acid, phenylacetic acid 78 and 83% respectively as phenylacetic acid, 3-phenylpropionic acid 96 and 105% respectively as benzoic acid and cinnamic acid, 70 and 70% respectively as benzoic acid.7. The concentration of aromatic acids in rumen fluid varied with time after feeding: cyclohexanecarboxylic acid was maximal (7 mg/l) 1 h after feeding, benzoic acid was always a minor component (0·5 ± 0·5 mg/l), phenylacetic acid varied between 0 and 35 mg/1 and 3-phenylpropionic acid between 25 and 47 mg/l. Cinnamic acid was not found in rumen fluid but on rumen infusion of this acid the concentration of 3-phenylpropionic acid in rumen fluid increased by 10 mg/l rumen fluid per g infused per d.8. The incomplete metabolism of quinic and cyclohexanecarboxylic acids to urinary benzoic acid is discussed. It is concluded that the principal dietary precursors of urinary benzoic acid in ruminants are compounds yielding 3-phenylpropionic acid on microbial fermentation in the rumen. The small amount of cinnamic acid characteristic of ruminant urine arises as an intermediate in the β-oxidation of 3-phenylpropionic acid in the body tissues.


1997 ◽  
Vol 77 (4) ◽  
pp. 577-592 ◽  
Author(s):  
J. H. Pagella ◽  
X. B. Chen ◽  
N. A. Macleod ◽  
E. R. Ørskov ◽  
P. J. S. Dewey

The quantitative relationship between the urinary excretion of benzoic acid (BA)and the uptake of 3-phenylpropionic (PPA) and cyclohexanecarboxylic (CHCA) acids was assessed.PPA and CHCA are produced in the rumen by microbial fermentation of lignocellulosic feeds and metabolized, after absorption, to BA which is excreted in the urine mainly as its glycine conjugate hippuric acid (HA). Four sheep nourished by intragastric infusions of all nutrients weregiven continuous ruminal infusions of PPA (8,16 or 24 mmol/d) either alone or with CHCA (8 or 16 mmol/d) in a factorial experiment. The treatments were allocated to ten consecutive 6 d periods, with a control being repeated at periods 1, 5 and 10. PPA and CHCA ruminal absorption rates, estimated using the liquid-phase marker Cr-EDTA, were 0·78 (SD 0·29)/h and 0·88 (SD 0·28)/h respectively. For the control, HA excretion was only 0·22 (SD 0·33) mmol/d and free BA was absent. For the other treatments, both HA and free BA were present and HA accounted for 0·85 (SD 0·05) of total BA. The urinary excretion of total BA showed a significant linear correlation (r = 0·997, P<0·001) with the amounts of PPA and CHCA infused. The urinary recovery of infused PPA and CHCA as total BA was 0·79 (SE 0·01). Faecal excretion of BA and its precursors was negligible. Results of this study show that urinary total BA is a potential estimator of the absorption of PPA + CHCA produced in the rumen


1983 ◽  
Vol 49 (1) ◽  
pp. 87-99 ◽  
Author(s):  
A. K. Martin ◽  
J. A. Milne ◽  
P. Moberly

1. Studies were made of the extent to which p-cresol, catechol, quinol and orcinol infused through rumen or abomasal cannulas to sheep were recovered in their urine.2. Rumen fermentation of dietary phenolic compounds caused the excretion of simple phenols in the urine. In decreasing order of magnitude these were: p-cresol, catechol, phenol and 4-methylcatechol with only traces of quinol and orcinol.3. The percentages of rumen-infused p-cresol or orcinol recovered as increments in the urinary phenol outputs of sheep (94 and 99% respectively) following infusion showed that rumen degradation of these phenols was negligible.4. After rumen infusion of catechol and quinol, mean recoveries of these phenols in urine were only 55 and 77% respectively. Possible reasons for these incomplete recoveries are discussed.5. Studies were also made of the use of the urinary phenol output of phenols characteristic of particular forages as indices of their voluntary intake by sheep. Calluna vulgaris L. (Hull) (heather) may contain 1300–3600 mg/kg dry matter (DM) of orcinol and 200–800 mg/kg DM of quinol as β-glycosides. When heather was offered ad lib. to sheep given one of five levels of grass, linear relationships were found between heather intake and urinary quinol and orcinol outputs.6. The urinary output of aromatic acids was also determined when sheep ate grass and heather. Urinary phenylacetic acid output was linearly related to grass but not to heather intake. The relationship between urinary phenylacetic acid output and grass intake could vary with different forages but that between orcinol output and heather intake was considered a useful index of heather intake.7. Methods for the assay of urine phenols are discussed.


1996 ◽  
Vol 1996 ◽  
pp. 179-179
Author(s):  
J.H. Pagella ◽  
X.B. Chen ◽  
N.A. MacLeod ◽  
E.R. Ãrskov

Microbial fermentation of lignoceluUosic feeds in the rumen produces 3-phenylpropionic (PPA) and cyclohexanecarboxylic (CHCA) acids. Feed phenolic cinnamic acids are regarded as the main precursors of PPA upon microbial action (Martin 1982b). CHCA can be produced by microbial metabolism of dietary alicyclic compounds such as quinic and shikimic acids (Balba and Evans, 1977; Martin, 1982a). Following absorption CHCA and PPA are subjected to metabolism mainly in the liver yielding benzoic acid (BA) which is extensively excreted in urine mainly as its glycine conjugate hippuric acid (HA). The aim of this work was to assess the quantitative relationship between the urinary excretion of total BA (free BA + HA) and the uptake of PPA and CHCA.


1996 ◽  
Vol 1996 ◽  
pp. 179-179
Author(s):  
J.H. Pagella ◽  
X.B. Chen ◽  
N.A. MacLeod ◽  
E.R. Ãrskov

Microbial fermentation of lignoceluUosic feeds in the rumen produces 3-phenylpropionic (PPA) and cyclohexanecarboxylic (CHCA) acids. Feed phenolic cinnamic acids are regarded as the main precursors of PPA upon microbial action (Martin 1982b). CHCA can be produced by microbial metabolism of dietary alicyclic compounds such as quinic and shikimic acids (Balba and Evans, 1977; Martin, 1982a). Following absorption CHCA and PPA are subjected to metabolism mainly in the liver yielding benzoic acid (BA) which is extensively excreted in urine mainly as its glycine conjugate hippuric acid (HA). The aim of this work was to assess the quantitative relationship between the urinary excretion of total BA (free BA + HA) and the uptake of PPA and CHCA.


1969 ◽  
Vol 23 (2) ◽  
pp. 389-399 ◽  
Author(s):  
A. K. Martin

1. The urinary excretions of total diethyl ether-soluble acids and total aromatic acids of three sheep given maintenance diets containing different proportions of hay, rolled oats and decorticated groundnut meal were determined.2. When the sheep were given the diet containing 70% rolled oats the excretion of aromatic acids in the urine was less than that observed when the sheep were given diets high in roughage or protein concentrates.3. The amounts of aromatic acids excreted in the urine were not related to the dietary intakes of crude protein, apparently digestible crude protein, crude fibre, lignin or cellulose.4. The excretion of comparatively large amounts of aromatic acids in the urine of ruminants is discussed in relation to the smaller amounts normally excreted by non-ruminants. Possible reasons for the failure to observe any relationship between the amounts of aromatic acids excreted in the urine of the sheep and those constituents of the diets that were investigated are discussed and the nature of other precursors is suggested.


1970 ◽  
Vol 118 (1) ◽  
pp. 47-51 ◽  
Author(s):  
J. W. Bridges ◽  
M. R. French ◽  
R. L. Smith ◽  
R. T. Williams

1. The urinary excretion of orally administered [14C]benzoic acid in man and 20 other species of animal was examined. 2. At a dose of 50mg/kg, benzoic acid was excreted by the rodents (rat, mouse, guinea pig, golden hamster, steppe lemming and gerbil), the rabbit, the cat and the capuchin monkey almost entirely as hippuric acid (95–100% of 24h excretion). 3. In man at a dose of 1mg/kg and the rhesus monkey at 20mg/kg benzoic acid was excreted entirely as hippuric acid. 4. At 50mg/kg benzoic acid was excreted as hippuric acid to the extent of about 80% of the 24h excretion in the squirrel monkey, pig, dog, ferret, hedgehog and pigeon, the other 20% being found as benzoyl glucuronide and benzoic acid, the latter possibly arising by decomposition of the former. 5. On increasing the dose of benzoic acid to 200mg/kg in the ferret, the proportion of benzoyl glucuronide excreted increased and that of hippuric acid decreased. This did not occur in the rabbit, which excreted 200mg/kg almost entirely as hippuric acid. It appears that the hedgehog and ferret are like the dog in respect to their metabolism of benzoic acid. 6. The Indian fruit bat produced only traces of hippuric acid and possibly has a defect in the glycine conjugation of benzoic acid. The main metabolite in this animal (dose 50mg/kg) was benzoyl glucuronide. 7. The chicken, side-necked turtle and gecko converted benzoic acid mainly into ornithuric acid, but all three species also excreted smaller amounts of hippuric acid.


2020 ◽  
Vol 16 (3) ◽  
pp. 328-334
Author(s):  
Jie Ge ◽  
Jin-Wen Wang ◽  
Qi-Yan Guo ◽  
Ai-Dong Wen

Objective: A validated liquid chromatography-tandem mass spectrometry method (LCMS/ MS) was established to simultaneously determine the concentration of triflusal and its main metabolite 2-hydroxy-4-trifluoromethyl benzoic acid(HTB) in human urine. Methods: The separation was performed on a Dikma C18 column using isocratic elution with acetonitrile-4 mmol/L ammonium acetate aqueous solution containing 0.3 % formic acid water (78: 28, V/V). The method involved extraction with methanol using protein precipitation. The precursor-toproduct ion transitions with multiple reaction monitoring was m/z 247.1→161.1, 204.8→106.7and 136.9→93.0 for triflusal, HTB and salicylic acid(IS), respectively. The method showed good linear relationships over the ranges of 0.08 to 48 μg/mL and0.5 to 50 μg/mL. Results: It was the first time that a urinary excretion study of triflusal capsule as oral. The cumulative urinary recovery showed 8.5% and 2.7% for triflusal and HTB, respectively. Conclusion: This method was successfully used for evaluating the pharmacokinetic properties of triflusal and HTB in urine in Chinese healthy subjects.


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