Eight Holstein cows were used to determine the relationship among milk urea nitrogen (MUN), plasma urea nitrogen (PUN), and feeding time. We first established that MUN concentrations were similar in concentration among quarters by comparing milk samples from each quarter just before milking. In order to determine if collecting a sample of milk from a quarter influenced the MUN in samples taken ...

BACKGROUND The in vivo quality of milk protein fractions has seldom been studied in humans. OBJECTIVE Our objective was to compare the postprandial utilization of dietary nitrogen from 3 [(15)N]-labeled milk products: micellar caseins (MC), milk soluble protein isolate (MSPI), and total milk protein (TMP). DESIGN The macronutrient intakes of 23 healthy volunteers were standardized for 1 wk,...

Relationships among plasma renin activities (PRA), plasma angiotensin II (ATII) concentrations, atrial natriuretic peptide (ANP) concentrations and cardiopulmonary function values were examined in dogs with ascitic pulmonary heartworm disease and acute- and chronic-vena caval syndrome (CS). PRA, plasma ATII concentration and plasma ANP concentration tended to be higher or were significantly hig...

TRUNIGER, BRUNO, AND BODIL SCHMIDT-NIELSEN. Intrarenal distribution of urea and related compounds: effects of nitrogen intake. Am. J. Physiol. 207(s) : 971-978. rg64.-Nitrogen and NaCl intake influence the excretion of urea. In rats maintained on a low-protein, high-salt intake the urea-to-inulin clearance ratio decreases to 0.01. In antidiuretic “low-protein” rats the urea concentrations in th...

A number of xenobiotics and certain pathophysiological situations cause the induction of CYP2E1. The present study was designed to establish the role of plasma urea nitrogen and L-arginine on hepatic CYP2E1 expression in rats or rats with acute renal failure. Exposure of rats to a single intravenous dose of 5 mg/kg uranyl nitrate caused renal failure in 5 days (ARF), as evidenced by increases i...

Investigations using ammonium citrate-(15)N and urea-(15)N showed that children in the acute stage of kwashiorkor and marasmus receiving a diet of adequate protein content retained a considerable percentage of the label from both compounds. Excretion of both total (15)N and urea-(15)N was subnormal and elimination was virtually completed 36 hr after administration of the isotope. During recover...

To determine whether circulating citrulline can be manipulated in vivo in humans, and, if so, whether citrulline availability affects the levels of related amino acids, nitric oxide, urinary citrulline, and urea nitrogen, 10 healthy volunteers were studied on 3 separate days: 1) under baseline conditions; 2) after a 24-h treatment with phenylbutyrate (0.36 g.kg(-1).day(-1)), a glutamine "trappi...

The urease (EC 3.5.1.5) inhibitor, phenylphosphoryldiamidate (PPDA), was given by continuous infusion into the rumen of two sheep nourished by intragastric infusion and into either the rumen or abomasum of four sheep given a pelleted diet containing 119 g crude protein (nitrogen x 6.25)/kg dry matter. PPDA was given at 1 g/d in infusion sheep and 1.5 g/d in the normally-fed sheep. Measurements ...

This study aimed to evaluate urea excretion, nitrogen balance and microbial protein synthesis in lactating goats fed with diets containing different protein sources in the concentrate (soybean meal, cottonseed meal, aerial part of cassava hay and leucaena hay). Four Alpine goats whose mean body weight was 42.6±6.1 kg at the beginning of the experiment, a mean lactation period of 94.0±9.0 days a...

The introduction of microchemical methods has made possible many biological investigations which were formerly precluded by the di5culty of obtaining sufficient amounts of material. This has been the case with studies on the blood and urine of fish. The only accurate quantitative chemical data are found in the recent papers of Dr. Denis’ on marine fish, where she reports results which indicate ...