Urinary excretion of purine derivatives as an index of microbial-nitrogen intake in growing rabbits
Ganuza, J. M.
Pérez, J. F.
Martin-Orúe, S. M.
González Ronquillo, Manuel
MetadataShow full item record
Three experiments were carried out to establish a response model between intake and urinary excretion of purine compounds. In Expt 1 the relationship between the intake of purine bases (PB) and the excretion of total purine derivatives (PD) was determined in seven growing rabbits with a mean initial live weight (LW) of 2.03 (SE 0.185) kg, aged 70 d, each fitted with a wooden neck collar to prevent caecotrophagy. They were fed on five experimental diets formulated with different levels of nucleic acids (0.00, 3.75, 730, 11.25, 15.00 g yeast-RNA/kg diet). The relationship between intake of purine (x, pmol/kg W"'75) and total urinary PD excretion b, pmol/kg WO"'), y = 0.56 + 0.67~(r 20 .86; RSD 0.338), indicated that about 70 % of duodenal PB were recovered as urinary PD and that the endogenous contribution was constant and independent of dietary PB supply. Endogenous excretion of PD (allantoin and uric acid) was measured in a second experiment using six rabbits fed on a purine-free diet and fitted with neck collars to avoid caecotrophagy. Basal daily urinary excretion values for allantoin and uric acid were 532 (SE 33.9) and 55 (SE 7.3) pmol/kg W0'7' respectively; xanthine and hypoxanthine were not found in urine samples and therefore the sum of allantoin and uric acid should comprise the total excretion of PD (588 (SE 40.1) pmol/kg W0'75). The xanthine oxidase (EC 220.127.116.11) activity in plasma, liver, duodenum, jejunum and kidney was measured in a third experiment. The activities of xanthine oxidase in duodenal and jejunal mucosa, liver and kidney were: 0.61 (SE 0.095), 0.37 (SE 0.045), 0.035 (SE 0.001) and 0 units/g fresh tissue respectively and in plasma 2.96 (SE 0.094) units/l. The results show that urinary excretion of PD may be a useful tool to estimate duodenal PB input and microbial protein intake once the relationship between PB and N has been established in caecal micro-organisms.
Is part ofBritish Journal of Nutrition, 1998, vol. 79, p. 373-380
European research projects
Showing items related by title, author, creator and subject.
Urinary excretion of purine derivatives as an index of microbial protein synthesis in the camel (Camelus dromedarius) Guerouali, Abdelhai; El Gass, Youssef; Balcells Terés, Joaquim; Belenguer, Álvaro; Nolan, John (Cambridge University Press, 2004)Five experiments were carried out to extend knowledge of purine metabolism in the camel (Camelus dromedarius) and to establish a model to enable microbial protein outflow from the forestomachs to be estimated from the ...
Modelling urinary purine derivatives excretion as a tool to estimate microbial rumen outflow in alpacas (Vicugna pacos) Orellana-Boero, P.; Seradj, Ahmad Reza; Fondevila, Manuel; Nolan, John; Balcells Terés, Joaquim (Elsevier, 2012-10)Three experiments were carried out to establish a model to estimate the forestomach microbial yield based on the urinary excretion of purine derivatives (PD: allantoin, uric acid, xanthine and hypoxantine) in alpacas ...
Excretion of endogenous and exogenous purine derivatives in sheep: effect of increased concentrate intake Pérez, J. F.; Balcells Terés, Joaquim; Cebrián, J. A.; Martin-Orúe, S. M. (Cambridge University Press, 1998)The present study examined the endogenous urinary excretion of purine derivatives (PD; allantoin, uric acid and xanthine plus hypoxanthine) in fed animals. Four Rasa Aragonesa ewes fitted with simple cannulas in the rumen ...