RESUMO
Four experiments were performed to study the kinetics of purine metabolism and urinary excretion in Zebu crossbred cattle. Fasting excretion was established in Expt 1, using eighteen male Bos indicus x Bos taurus crossbred cattle (261 (SE 9.1) kg body weight), six of each of the following genotypes: 5/8 Bos indicus, 1/2 Bos indicus and 3/8 Bos indicus. No significant differences were observed among genotypes in fasting purine derivative excretion (277.3 (SE 35.43) micromol/metabolic body weight). In a second experiment we measured the xanthine oxidase activity, which was higher in liver than in duodenal mucosa (0.64 and 0.06 (SE 0.12) units/g wet tissue per min respectively; P>0.05) being in plasma 0.60 (SE 0.36) units/l per min. The kinetics of uric acid were measured by intravenous pulse dose of [1,3-15N]uric acid (Expt 3). The cumulative recovery of the isotope in urine was 82 (SE 6.69) %, and uric acid plasma removal, pool size and mean retention time were 0.284 (SE 0.051) per h, 5.45 (SE 0.823) mmol and 3.52 (SE 0.521) h, respectively. Allantoin was removed from plasma at an estimated fractional rate of 0.273 (SE 0.081) per h and mean retention was 3.66 (SE 1.08) h. In Expt 4, the relationship between urinary purine derivative excretion (Y; mmol/d) and digestible organic matter intake (X, kg/d) was defined by the equation: Y=7.69 (SE 4.2)+5.69 (SE 1.68) X; n 16, Se 1.31, r 0.67.
Assuntos
Bovinos/metabolismo , Purinas/metabolismo , Animais , Bovinos/urina , Duodeno/enzimologia , Ingestão de Alimentos/fisiologia , Jejum/metabolismo , Jejum/urina , Intestinos/enzimologia , Fígado/enzimologia , Masculino , Purinas/urina , Ácido Úrico/urina , Xantina Oxidase/sangue , Xantina Oxidase/metabolismoRESUMO
Neste estudo foram avaliados o pH e a cristalúria de estruvita em amostras de urina in vivo e in vitro de gatos alimentados com três tipos de rações secas A, B e C, fornecidas ad libitum, após um período de 15 horas de jejum. O grupo experimental constou de dez gatos adultos, S.R.D, sendo oito fêmeas e dois machos. Houve diferença significativa (p<0,05) entre as médias obtidas dos pH urinários nos três períodos pós-prandiais, que foram 6,7 para ração A; 7,5 para ração B e 6,8 para ração C, e as respectivas médias dos pH urinários no três períodos em jejum, que foram 5,6; 6,1 e 5,9. Conclui-se que o jejum alimentar de 15 horas contribuiu para a acentuada maré alcalina pós-pradial, não sendo recomendado este tipo de manejo alimentar quanto ao fornecimento de dietas secas e que o pH é fator limitante in vivo e in vitro na formação de cristais de estruvita. A quantidade de cristais de estruvita aumentou na faixa de pH urinário entre 7,0 e 7,4 ou superior
In three separate experiments 10 cats (8 female and 2 male) were fed ad libitum, after fifteen hours fasting, with commercially available dry diets A, B, C. Urine samples were taken and pH and the differences of struvite crystals in their sediment estimated in vivo and in vitro. There was significant differences (p<0,005) in urine pH between postprandial period with diet A (6.7), diet B(7.5) and diet C (6.8) and fasting period, with the three diets: diet A (5.6), diet B (6.1) and diet C (5.9). It was concluded that dry diets significantly raised urine pH when the cats were fed after a 15-hour fast. This emphasizes that, for a maximum effectiveness, such a diet should be available ad libitum, thus permitting the consumption of small and frequent meals. Urine pH was as important in vivo and in vitro in Struvite precipitation, and this was noticed when the pH was 7.0 and 7.4 or higher than this
Assuntos
Animais , Lactente , Gatos , Gatos , Jejum/urina , Ração Animal , UrinaRESUMO
Neste estudo foram avaliados o pH e a cristalúria de estruvita em amostras de urina in vivo e in vitro de gatos alimentados com três tipos de rações secas A, B e C, fornecidas ad libitum, após um período de 15 horas de jejum. O grupo experimental constou de dez gatos adultos, S.R.D, sendo oito fêmeas e dois machos. Houve diferença significativa (p<0,05) entre as médias obtidas dos pH urinários nos três períodos pós-prandiais, que foram 6,7 para ração A; 7,5 para ração B e 6,8 para ração C, e as respectivas médias dos pH urinários no três períodos em jejum, que foram 5,6; 6,1 e 5,9. Conclui-se que o jejum alimentar de 15 horas contribuiu para a acentuada maré alcalina pós-pradial, não sendo recomendado este tipo de manejo alimentar quanto ao fornecimento de dietas secas e que o pH é fator limitante in vivo e in vitro na formação de cristais de estruvita. A quantidade de cristais de estruvita aumentou na faixa de pH urinário entre 7,0 e 7,4 ou superior(AU)
In three separate experiments 10 cats (8 female and 2 male) were fed ad libitum, after fifteen hours fasting, with commercially available dry diets A, B, C. Urine samples were taken and pH and the differences of struvite crystals in their sediment estimated in vivo and in vitro. There was significant differences (p<0,005) in urine pH between postprandial period with diet A (6.7), diet B(7.5) and diet C (6.8) and fasting period, with the three diets: diet A (5.6), diet B (6.1) and diet C (5.9). It was concluded that dry diets significantly raised urine pH when the cats were fed after a 15-hour fast. This emphasizes that, for a maximum effectiveness, such a diet should be available ad libitum, thus permitting the consumption of small and frequent meals. Urine pH was as important in vivo and in vitro in Struvite precipitation, and this was noticed when the pH was 7.0 and 7.4 or higher than this(AU)