Mammalian sirtuins have diverse roles in aging, metabolism and disease. Recently we reported a new function for SIRT5 in urea cycle regulation. Our study uncovered that SIRT5 localized to mitochondria matrix and deacetylates carbamoyl phosphate synthetase 1 (CPS1), an enzyme which is the first and rate-limiting step of urea cycle. Deacetylation of CPS1 by SIRT5 resulted in activation of CPS1 en...

The purpose of this study was to determine if carbamoyl phosphate synthetase III (CPSase III) and related urea cycle enzyme activities in skeletal muscle tissue of juvenile rainbow trout (Oncorhynchus mykiss) increase during short- or long-term exercise, in parallel with changes in whole-body urea excretion rates. Urea excretion was elevated by 65% in fish that swam at high-speed (50 cm/s) vs. ...

Investigations in our laboratory have established that infection with SalmoneUa pulorum strain CDC 3522/51 results in a decrease in arginine, methionine, glycine and tryptophan in the blood and liver of 1to 3-day old White Leghorn cockerels (Ross et al., 1955a). Subsequent experiments revealed that the administration of arginine within 24 hr following infection produced a marked increase in sur...

Grøfte, Thorbjørn, Dorthe Svenstrup Jensen, Henning Grønbæk, Troels Wolthers, Søren Astrup Jensen, Niels Tygstrup, and Hendrik Vilstrup. Effects of growth hormone on steroid-induced increase in ability of urea synthesis and urea enzyme mRNA levels. Am. J. Physiol. 275 (Endocrinol. Metab. 38): E79–E86, 1998.—Growth hormone (GH) reduces the catabolic side effects of steroid treatment due to its e...

The effect of intake on urea production, entry into the digestive tract and return of N to the ornithine cycle was studied in four sheep. Each sheep received 0.6, 1.2 and 1.8 x estimated maintenance energy intake quantities of grass pellets for 9 d. After 4 d of adjustment, N balance measurements were conducted between days 5 and 8. From day 7 to day 9 animals were continuously infused, via the...

Two experiments (n = 46 and 56, respectively) were conducted to evaluate urea dilution as an estimator of body composition in lambs and to address certain procedural and mathematical considerations in this technique. In Exp. 1, 14 blood samples were taken over 240 min after urea infusion. The equation describing the urea clearance curve was: delta PUN = 9.7e-.1727(min) + 10.4e-.0021(min), pools...

BACKGROUND Behcet's disease (BD) is a multisystem disease of unknown etiology. There are several clues which may indicate an ethiopathogenesis role for Helicobacter pylori infection in this disease. METHODS In a case control study in an out patient department, 48 patients with BD were compared to age, sex matched controls regarding presence of H. pylori infection by serology and urea breath t...