Total acid excretion

Since ammonia is added to the urine by the renal tubular cells themselves, the amount of urinary acid buffered as ammonium ions is not included in the titratable acid. To estimate the contribution of ammonia, we must directly measure the amount of ammonium ions in the urine and add this to the titratable acid. This is called the total acid excretion ... 

Total acid excretion The total acid excretion of the urine is the quantity of ammonium ions found in the urine plus the titratable acid. 

Similar metabolites were found produced by man (19)(20)(21)t monkeys( ), dogs (8), chickens(22)> calves(23) and microorganisms(4). The ratios of these metabolites, however, were found to vary with the individual. The overall conversion of nalidixic acid to hydroxynalidixic acid had been reported by McChesney(S) to be normally about 32% bicarbonate supplementation increased this to about 40%. Bicarbonate supplementation also increased the amount of total naphthyridine excreted in the biologically active form. 

Ml. Marko, A. M., Gerrard, J. W., and Buchan, D. J., Glutamic acid derivatives in adult celiac disease. II. Urinary total glutamic acid excretion. Can. Med. Assoc. J. 83, 1324-1325 (1960). 

When male Wistar rats were exposed to -hexane at concentrations up to 3,074 ppm for 8 hours, analysis of urine showed that 2-hexanol was the major metabolite, accounting for about 60-70% of the total metabolites collected over the 48-hour collecting period (Fedtke and Bolt 1987). This is in contrast to humans, in which the major urinary metabolite is 2,5-hexanedione (Perbellini et al. 1981). The amounts of metabolites excreted were linearly dependent on the exposure concentration, up to an exposure of about 300 ppm. 2-Hexanol and 2-hexanone were detected in the first sample (obtained during the 8-hour exposure) excretion of 2,5-hexanedione was delayed and was not detected until 8-16 hours after exposure began. The amount of 2,5-hexanedione detected depended on sample treatment total excreted amounts over 48 hours were approximately 350 g/kg 2,5-hexanedione without acid treatment and 3,000 g/kg with total acid hydrolysis, indicating conversion of 4,5-dihydroxy-2-hexanone with acid treatment. 

In addition to more rapid absorption of lipids in animals fed casein, another mechanism that may be operative is decreased clearance of circulating lipids. Rabbits fed a casein-based semipurified diet excreted significantly less cholesterol but more bile acids in their feces than animals fed a commercial diet (18). The total sterol excretion in feces of the animals fed the casein diet was half that of the rabbits fed the stock diet. Huff and Carroll (19) found that rabbits fed soy protein had a much faster turnover rate of cholesterol and a significantly reduced rapidly exchangeable cholesterol pool compared with rabbits fed casein. Similar studies performed in our laboratory revealed that the mean transit time for cholesterol was 18.4 days in rabbits fed soy protein, 36.8 days in rabbits fed casein, 33.7 days in rabbits fed soy plus lysine, and 36.3 days in rabbits fed casein plus arginine. These data suggest that addition of lysine to soy protein... 

Vrij-Standhardt WG, Strik JJ, Ottevanger CF. 1979. Urinary D-glucaric acid and urinary total porphyrin excretion in workers exposed to endrin. In Strik JJ, Koeman JH, eds. Chemical porphyria in man. Amsterdam Elsevier/North Holland Biomedical Press, 113-121. 

Cholesterol level decrease. The husks and seeds were administered orally to six normal adult males and five adult males with ileostomy and six normal adult males and four adult males with ileostomy, respectively, at a dose of 10 g/day for 3 weeks. The husk had no effect on cholesterol or triglyceride concentrations in either normal or ileostomy subjects. Total and HDL cholesterol concentrations were reduced on average by 6.4 and 9.3%, respectively, in normal group after seed supplementation. No effect on fecal bile acid excretion in the normal subjects was found after both regimens. Ileostomy bile acids were increased (on average 25%) after seed supplementation, whereas no effect on cholesterol concentrations was found. These results suggest that psyllium seed may be more effective than the husk in... 

The total amount of trichloroethanol and trichloroacetic acid excreted in urine accounts for 77% of the predicted amount of metabolized 1,1,1-trichloroethane. Excretion of trichloroethanol and trichloroacetic acid in urine is slow in relation to exhalation of... 

Total neutral sterol excretion by mice (male, C57BL/6) fed a chow diet is typically 80 15 nmol per day per gram body weight and bile acid excretion is 50 10 nmol per day per g body weight. On semi-purified diets, which are low in fiber and reduce gut motility, neutral sterol excretion is reduced as much as 50% and bile acid excretion can be reduced as much as 5-fold or more (unpublished results). Thus, the diet used in a given study must be chosen carefully. Since human diets have a tendency to be low in fiber, a chow diet may partially mask potential treatment benefits because sterol excretion is already quite high. 

In children above 2 years of age, the situation is not substantially different from adults as far as the relative amounts of amino acids excreted are concerned. In fact, only very few really satisfactory data have been obtained so far in urines from children above 2 years of age. We present therefore in Fig. 3 a typical chromatogram of a 24-hr specimen of urine of a normal child, 2 years old, as drawn from Vis observations. Comparison of quantitative data concerning daily excretions are rendered difficult because of the differences in body size. The 24-hr basis alone is not suitable. It is necessary to compare data on the basis of percentage of total nitrogen excretion, or per kilogram of body weight, a procedure adopted by Jonxis and Huisman. We do not believe it suitable or safe to choose a comparison factor based on creatinine excretion. 

In early infancy the situation is known to be quite different from that among older children. Simon noticed in 1911 that the newborn infant excreted 10 % of its total nitrogen output in the form of amino nitrogen, whereas in adults it drops to 2 % (S15). This was confirmed in later years (B4, Cll, G5) and extended to the study of individual amino acid excretion by microbiological methods (S10, Sll), by paper chromatography (S20, S21), and finally by ion exchange column chromatography (D28, D30) at the time Moore and Stein s first method of 1951 was still the only one available. 

A plasma calibration curve for ll-nor-A9-THC-9-carboxylic acid, 5a, is shown in Figure 9. There was reasonable linearity from 1.0-50 ng/ml plasma with detection limits of 0.5 ng or less per ml. Figure 10 presents similar data for a urine calibration curve. The method showed reasonable linearity between 2.0-100 ng/ ml urine. Figure 11 presents pharmacokinetic data. for plasma levels of a human volunteer, BS, over a 0.5 hour to 48 hour period comparing A9-THC and 11-nor acid levels after a dose of 5.0 mg of A9-THC by the intravenous route. Both parent compound and acid metabolite exhibited a biphasic elimination pattern although the levels of the acid did not fall as rapidly as parent compound. Elimination of the acid metabolite 5a in urine is shown in Figure 12. It is evident that urinary elimination proceeded rapidly as 80% of the total 11-nor-acid excreted was eliminated in the urine during... 

Cohurn SP, Thampy KG, Lane HW, Conn PS, Ziegler PJ, Costill DL, Mahuren JD, Fink WJ, Pearson DR, Schaltenhrand WE, et al. (1995) Pyridoxic acid excretion during low vitamin B-6 intake, total fasting, and hed rest. American Joumai ofCiinicai Nutrition 62,979-83. 

Total and % Excretion of Kynubenic and Xanthurenic Acids by 18 Pregnant Women AT Different Stages of Pregnancy after Tryptophan Loading ... 

Sudakova and Ryvkin (S9) studied 52 patients of different ages with active rheumatism and determined their pyridoxine deficiency through the degree of disturbed tryptophan metabolism in the form of increased rates of xanthurenic acid excretion in urine. After a load of tryptophan the concentration of xanthurenic acid in urine of 40 patients rose to higher levels, in some cases as high as 300 mg, with a total average of 97 mg. Urinary xanthurenuria remained normal in only 9 patients... 

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