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At least 19 recordsLinked to original sources
PubMed1979

[Investigations on 131I-hippurate-clearance in obstructive-uropathy; extraction of para-aminohippuric acid and 131I-hippurate in the acutely obstructed canine kidney (author's transl)].

The results of more recent clinical and experimental investigations have thrown doubt on the usefulness of determining the individual 131I-hippurate clearance for evaluation of the function of acutely obstructed kidneys. There is a significant difference (5% level) between the kidney performance determined with external measurement on the one hand and with PAH and 125I-hippurate clearance in the steady state on the other. With the steady state method, the restriction of function to be expected in consequence of urinary obstruction is demonstrated, whereas with simultaneous measurement with catheterless 131I-hippurate clearance, an increase in function is detected. In the clearance studies carried out in the conventional way with PAH and 125I-hippurate, it was difficult to determine quantitatively the urine produced during urinary obstruction. The renal extraction of p-aminohippuric acid and 131I-hippurate was therefore determined in simultaneous measurement in six dogs before and after acute urinary obstruction with a constant plasma level of the test substances. The results obtained with this very elaborate method which is, however, independent of urine collection show that an acute urinary obstruction leads to a decrease of renal extraction both of PAH and of 131I-hippurate. Since with conventional clearance, the measurement result is proportional to the amount of substance excreted with the urine, a restriction of function must also result with the steady state methods in determining the performance of acutely obstructed kidneys. The results of the extraction investigations hence confirm the results of the clearance studies mentioned. In addition, they show that the "increase" of renal performance immediately after an experimentally induced urinary obstruction repeatedly found with catheterless determination of 131I-hippurate-clearance cannot be explained by a different kinetic behavior of PAH and 131I-hippurate in the acutely obstructed kidney.

Acute Disease↗
PubMed1978

Binding of hippurate in normal plasma and in uremic plasma pre- and postdialysis.

The protein binding of 14C-hippurate has been measured by conventional ultrafiltration techniques in the plasma of normal subjects and in uremic subjects pre- and postdialysis. In addition, the clearance of 14C-hippurate was determined in vitro in both isotonic saline and plasma to assess binding limitations on hippurate removal during dialysis. Binding levels of hippurate in normal subjects of 68+/-1.8% (n = 5) were significantly higher than either postdialysis (48.3+/-15.4%; n = 7) or predialysis (36.6+/-11.7%; n = 7) levels in the same uremic subjects. Actual levels of plasma hippurate were, however, considerably greater in uremics (24.7+/-11.2 mg/dl' n = 7) than in normal subjects (congruent to 0.5 mg%). The difference in hippurate binding between pre- and postdialysis samples in uremics was significantly different from zero (p less than 0.01, t = 5.36), indicating depletion of competitive site-binding species during dialysis. The saline clearance of hippuric acid (99.1 +/-0.5 ml/min; n = 6) under standard conditions in a capillary dialyzer (CDAK-4) was consistent with the expected clearance of a solute of its molecular weight. Hippurate clearance in citrated plasma, where binding was determined as 50+/-3%, was 65+/-0.7 ml/min (n = 6), in good agreement with a theoretically predicted clearance of 60 ml/min for this level of binding. High serum levels of hippurate and its derivatives, may depress effective function of various organs. In addition to the normal dietary intake of hippurate and its precursors, patients on dialysis receive a further burden of hippurate precursor in the form of benzyl alcohol, the common preservative in heparin solutions. The large body burdens of hippurate in dialysis patients, coupled with its impaired removal on dialysis due to binding, point to the necessity for a through investigation of the potential toxicity of this compound.

Carbon Radioisotopes↗
PubMed1977

The synthesis of hippurate from benzoate and glycine by rat liver mitochondria. Submitochondrial localization and kinetics.

1. Rat liver mitochondria make hippurate at up to 4 nmol/min per mg of protein. The rate of synthesis supported by oxidation of glutamate with exogenous Pi present is identical with that supported by ATP plus oligomycin. Lower rates were obtained with other respiratory substrates, and when glutamate was used without Pi. 2. A matrix localization for hippurate synthesis is indicated by the latency of benzoyl-CoA synthetase and glycine N-acyltransferase to their extramitochondrial substrates, failure of exogenous benzoyl-CoA to inhibit incorporation of [14C]hippurate and inhibition of hippurate synthesis supported by ATP, but not glutamate, by carboxyatractyloside. 3. The relative activities of the individual enzymes and the mitochondrial content of benzoyl-CoA in the presence and absence of glycine suggest that hippurate synthesis is rate-limited by formation of benzoyl-CoA. 4. The increases in rates of ATP hydrolysis and of O2 consumption on the addition of benzoate and glycine were in good agreement with those required to support hippurate synthesis. The increase in respiration indicates that State-4 respiration [Chance & Williams (1957) Adv. Enzymol 17, 65-134] is not used, with these conditions, for ATP synthesis.

Adenosine Triphosphate↗
PubMedDate not supplied

Long-term treatment with methenamine hippurate in recurrent urinary tract infection.

Twenty-four patients with a history of recurrent urinary tract infection and in whom residual urine was considered to be a factor of importance for chronicity, have been treated for an average of 16 months with 1 g methenamine hippurate morning and evening. No patient had urinary calculus at the commencement of treatment and neither did any patient have an indwelling catheter. In patients without urinary tract infection or in whom abacteriuria was achieved with methenamine hippurate, the number of reinfections was reduced by approximately two thirds compared to periods prior to treatment. No patient was completely free from infection throughout the whole treatment period. However, in no case did bacteria with extensive resistance appear. When urinary tract infection was treated with methenamine hippurate, abacteriuria was achieved in only 6 of 14 patients. It would therefore seem that this agent is only of limited value for treatment of established infection. In the event of manifest infection it would appear appropriate to treat the infection primarily with antibiotics and to use methenamine hippurate for prophylaxis when abacteriuria has been achieved. No patient developed urinary calculus during treatment with methenamine hippurate and no deterioration of renal function or haematological change was observed.

Adult↗
PubMed1976

Post-mortem survival of hippuric acid formation in rat and human cadaver tissue samples.

1. A rapid and sensitive semi-micro method for the determination of hippuric acid formation by tissue samples in vitro is described and applied to the determination of the post-mortem survival of hippuric acid formation in rat and human cadaver tissue samples. 2. Hippuric acid formation survived in rat and human cadaver liver for at least 72 h when corpses were stored at 4 degrees. 3. Hippuric acid formation was detected in human cadaver liver and kidney samples and was absent from brain, intestine, heart and lung. 4. Post-mortem liver samples from a case of acute pancreatitis failed to form hippuric acid as did kidney samples from a case of systemic lupus erythematosus with renal involvement.

Adult↗
PubMed1977

Evaluation of the rapid hippurate hydrolysis test with enterococcal group D streptococci.

The rapid hippurate hydrolysis test was evaluated with the conventional test, using 17 group A streptococci, 9 non-enterococcal group D streptococci, 108 enterococcal group D streptococci, and 2 strains of Listeria monocytogenes. There was complete correlation between the rapid and conventional tests with all organisms except enterococcal group D. The rapid hippurate hydrolysis method was more sensitive with the enterococci; 95.4% were positive with the rapid method, and 9.3% were positive with the conventional method. Thin-layer chromatography (TLC) was performed on all isolates to determine if the end product of hydrolysis, glycine, was indeed present. The TLC results were in agreement with the rapid and conventional methods for group A streptococci, nonenterococcal group D streptococci, and L. monocytogenes. TLC results were in total agreement with the rapid hippurate hydrolysis test for the enterococcal group D isolates, thus verifying the accuracy of this more sensitive test. Trace amounts of glycine were found in the substrate, indicating the need for including an uninoculated substrate control as well as stock strains of group A and B beta-hemolytic streptococci (negative and positive controls, respectively) each time the rapid hippurate hydrolysis test is performed.

Amidohydrolases↗
PubMed1977

Quantitative determination of hippuric and m-methylhippuric acids in urine by high-speed liquid chromatography.

High-speed liquid chromatography employing an ultraviolet photometric detector has been applied to the simultaneous determination of hippuric and m-methylhippuric acids in urine. Reversed-phase partition chromatography is carried out on a muBondapak C18 column with methanol-water as the eluent system. This method obviates the necessity for isolation or reaction of these acids before assay. The only pretreatment necessary is extraction of sample with ethyl acetate. A linear relationship is obtained between the peak heights and the hippuric or m-methylhippuric acid concentrations. Mean recovery of hippuric and m-methylhippuric acids in urine is 99.8% and 99.3% respectively. The determination of hippuric acid by this method gives lower concentrations in normal urine than does the colorimetric method of Umberger and Fiorese (1963).

Chromatography, High Pressure Liquid↗
PubMed1978

Urinary hippuric acid concentration after occupational exposure to toluene.

The results of industrial investigations have shown a correlation between the rate of hippuric acid excretion in a single urine sample collected after daily occupational exposure and the amount of toluene absorbed. The rate of hippuric acid excretion and the average concentration of toluene vapour during exposure time were also related. The quantitative range of the test has been limited to amounts exceeding 425 mg of toluene and concentrations exceeding 69 ppm of toluene in the air because of the physiological presence of hippuric acid in urine. The rate of hippuric acid excretion in urine depends on diuresis and is constant for urinary fractions with diuresis of 30 ml/h. The physiological excretion rate was 20 mg/h with a standard deviation +/- 4.3 mg/h, maximal physiological level 33 mg/h.

Diuresis↗
PubMed1975

Uricosuric agents in uremic sera. Identification of indoxyl sulfata and hippuric acid.

Serum and urine from chronically uremic patients and normal individuals were subjected to gel filtration of Sephadex-G10. The effects of the eluted fractions on the uptake of urate and para-aminohippurate by isolated cortical tubules of rabbit kidney were investigated. According to the origin of the samples, one to three major groups of fractions inhibiting both urate and para-aminohippurate transport were disclosed. The first eluted group occurred for all the samples under study. The second one was demonstrated in both sera and urines from uremic patients but only in urines from normal individuals. The third one was exclusively detected in uremic sera and urines. Among all the compounds identified, only hippuric acid, eluted in the fractions of the second group, was capable of inhibiting the uptake of urate and para-aminohippurate in vitro. The concentration for which this inhbiitory effect of hippuric acid occurred was in the range of that existing in uremic sera. Indoxyl sulfate, which accumulates to very high concentrations in uremic serum, could not be disclosed in the above-mentioned fractions. This is explained by the strong adsorption of this indole derivative to Sephadex gel. Potassium indoxyl sulfate, when tested in vitro at the concentration existing in uremic serum, substantially inhibited the uptake of both urate and para-aminohippurate. In normal subjects, ingestion of hippuric acid or potassium indoxyl sulfate significantly increased fractional urinary excretion of uric acid. On the basis of these results, it is suggested that progressive retention of hippuric acid, indoxyl sulfate, and other yet unidentified inhibitors may explain the gradual increase in urinary fractional excretion of urate observed in uremia. The present results may be viewed as an example of a mechanism in which retention of normally excreted end products is responsible for adaptation of tubular transport in uremic subjects.

Aminohippuric Acids↗
PubMed1979

[The excretion of hippuric acid and ascorbic acid in the urine of liver-damaged rats (author's transl].

The authors investigated the effects of the administration of thioacetamide, carbon tetrachloride and aminophenazone on the excretion of ascorbic acid and hippuric acid in adult male and female Wistar rats. After a single application of thioacetamide and aminophenazone, the ascorbic acid content in the urine showed a dose-dependent increase, whereas that in the liver had decreased. This increase in the urinary ascorbic acid might be due to a release of stored ascorbic acid from the liver cells. When thioacetamide was given for a prolonged period, the ascorbic acid content in the urine increased at the beginning; later one, at the end of three weeks, it was slightly inferior to the control value. Both single and repeated applications of thioacetamide led to a decrease in the excretion of hippuric acid in the urine, which is attributed to an impairment of the mitochondrial hippuric acid synthesis. Long-term treatment with aminophenazone resulted in an increase of ascorbic acid in the urine, which is indicative of an induction effect, whereas the ascorbic acid content in the liver remained unchanged. There was no effect on the excretion of hippuric acid. In regard to their use in the toxicological evaluation of drugs, these two metabolic effects offer no decisive advantage over current liver function tests.

Aminopyrine↗
PubMed1975

[Transport of 131J-iodo-o-hippurate and 22Na out of the retroretinal space in experimental non rhegmatogenous detachment of the retina (author's transl)].

A model of an experimental arhegmatogenous retinal detachment is presented, to allow the measurement of the transport of radioactive labeled substances out of the subretinal space. Experiments were performed on 19 male cats. 131I-iodo-o-hippurate and 22Na were used as test substances. There was no significant difference between the rate of disappearance of 131I-hippurate if injected retroretinally or intravitreally. The rate of disappearance of 131I-hippurate could be slowed down by intravenous infusion of penicillin-G. The rate of disappearance of 22Na following retroretinal injection is not only slower than the rate of disappearance of 22Na injected intravitreally, but significantly slower than the rate of disappearance of 131I-hippurate. For graphic analysis ("curve peeling") of the terms embodied in the curves, more densly situated points of measurements will be necessary. Then the experimental model will serve well to analyze the components influencing the transport of labeled sodium out of the subretinal space.

Animals↗
PubMed1976

Rapid, colorimetric test for the determination of hippurate hydrolysis by group B Streptococcus.

A colorimetric test for the determination of hippurate hydrolysis was developed. Brain heart infusion broth made with 1% sodium hippurate served as the test medium. Hydrolysis was determined by the addition of two chemical developers, M (rhodamine B) and A (uranium acetate). A dark pink color indicated hydrolysis; no color change indicated no hydrolysis. The method was efficacious in either rapid or overnight incubation. One hundred twenty-five strains of group B, 44 strains of group A, 15 strains of group C, and 10 strains of group G Streptococcus were tested. By using the Lancefield method as the standard, there was 100% agreement with both the colorimetric and ferric chloride tests for hippurate hydrolysis, and 96% agreement with the CAMP test.

Hippurates↗
PubMed1977

Measurement by gas chromatography of urinary hippuric acid and methylhippuric acid as indices of toluene and xylene exposure.

A gas chromatographic method was applied to the determination of the urinary glycine conjugates, hippuric, o-, m- and p-methylhippuric acids. These were extracted with ethyl acetate from urine after acidification with hydrochloric acid. The internal standard solution (heptadecanoic acid methanol solution) was added before extraction and a diazomethane-ether-ethanol solution was subsequently added to the dried extracts. The methylated residues were dissolved in methanol and injected into a gas chromatograph as described by Buchet and Lauwerys (1973). By the combined use of gas chromatography and mass spectrometry the methyl esters of hippuric acid and m-methylhippuric acid were identified in the urine of a volunteer who had been exposed to toluene and m-xylene vapours. When the urine specimen contained salicyluric acid (a urinary metabolite of salicylic acid) two sharp peaks were observed. The faster peak coincided with m- or p-methylhippuric acid. The upper limit of urinary hippuric acid concentration in healthy subjects with no occupational exposure was calculated by this method to be 1.026 microgram/ml (fiducial limit 5%) after correction to 1.024 for variation in urinary density.

Adult↗
PubMed1975

Controlled trial comparing co-trimoxazole and methenamine hippurate in the prevention of recurrent urinary tract infections.

To study the effects of continous low doses of antibacterial agents after eradication of bacteriuria in patients with recurrent urinary tract infection, 31 patients with documented recurrent urinary tract infection were allocated alternately to treatment with either co-trimoxazole (400 mg of suphamethoxazole and 80 mg of trimethoprim each night) or methenamine hippurate (1 g each night). The majority of patients (79%) had underlying radiological abnormalities of the renal tract, but normal renal function (the mean serum creatinine level was 1.05 mg per 100 ml). During the study the incidence of bacteriuria and pyuria was significantly lower in the co-trimoxazole-treated group. Patients receiving co-trimoxazole also had fewer acute clinical episodes of urinary tract infection than patients receiving methenamine hippurate. There were no significant side effects from either drug. Two patients with frequent recurrences of infection developed renal calculi. No change in creatinine clearance or maximum urinary concentrating ability was observed over a follow-up period of four to 30 months (mean 10.4 months). Co-trimoxazole is an effective agent in the prophylaxis of urinary tract infection in this highly susceptible group of patients, and in the doses used was superior to methenamine hippurate.

Adult↗
PubMed1975

[Transport of 131I-hippuric acid and 22Na from the space between retina and pigment epithelium after experimental amotio].

A method was developed which allows up to puncture and fill the virtual space between retina and pigment epithelium with radioactive-labeled substances and to measure the transport of the injected substances out of this space. Experiments have been performed on 28 cats. 131I-iodo-omicron-hippurate and 22Na were used. The transport out of the space between retina and pigment epithelium of 22Na is much slower than that of 131I-iodo-omicron-hippurate. It is concluded that an active system in the pigment epithelium and/or retina is responsible for the transport of iodo-omicron-hippurate out of the eye

Absorption↗
PubMed1977

Methenamine and its salts as urinary tract antiseptics: variables affecting the antibacterial activity of formaldehyde, mandelic acid, and hippuric acid in vitro.

The activities of formaldehyde and of mandelic and hippuric acids, alone and in combination, have been tested against some 300 strains of bacteria typical of those causing urinary tract infections. In a chemically defined medium, which resembles urine in many respects, formaldehyde had a mean minimal inhibitory concentration of 13 mug per ml. Activity was several fold lower in media (nutrient agar and tryptic soy agar) that contained significant amounts of protein. The activity of formaldehyde is virtually unaffected by pH in the range of 5 to 8. Mandelic and hippuric acids (2 mg per ml) have limited antimicrobial activity at acid pH values only. The combination of formaldehyde with mandelic acid (2 mg per ml) was additive, most markedly at pH 5; the formaldehyde-hippuric acid combination, however, did not appear to be additive. Our findings suggest that, at pH values between 5 and 6, an antibacterial concentration of formaldehyde will be generated from methenamine within approximately 1 hr after being excreted into the urine.

Anti-Infective Agents, Urinary↗
PubMed1977

An improved direct colorimetric method for the quantitative analysis of urinary hippuric acid as an index of toluene exposure.

An improved direct colorimetric method for determining the concentration of urinary hippuric acid as an index of toluene exposure was described. One tenth ml of urine was diluted with 0.4 ml 0.01 M phosphate buffer H 6.9 and mixed with 0.5 ml pyridine. The mixture was layered on 0.2 ml benzenesulfonyl chloride. The reaction was started by mixing for one min with a mechanical shaker. The colored solution was allowed to stand for 30 min, diluted with 5 ml ethanol, and absorbance measured at 410 nm within 30 min after the dilution. The coefficient of variation of this method was 6% and the recovery 103% when urine contains about 0.2-0.5 mg hippuric acid per ml of urine. The concentration was linear up to 2.0 mg per ml hippuric acid in a specimen.

Chromatography, High Pressure Liquid↗