Is N-acetylglutamate a short-term regulator of urea synthesis?

نویسندگان

  • P Lund
  • D Wiggins
چکیده

A method is described for determining N-acetylglutamate as glutamate. N-Acetylglutamate content of hepatocytes from 48 h-starved rats is high. It shows no parallelism with rates of urea synthesis from glutamine. We question its accepted function as a short-term regulator of urea synthesis.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The regulation of carbamyl phosphate synthetase (ammonia) in rat liver mitochondria. Effects of acetylglutamate concentration and ATP translocation.

1. Mitoplasts, unlike mitochondria, are readily permeable to acetylglutamate; by incubating mitoplasts with different external [acetylglutamate] a wide range of concentrations of this cofactor in the matrix can be obtained, which can be correlated directly with the velocity of carbamyl phosphate synthetase (ammonia). 2. The relationship between carbamyl phosphate synthetase (ammonia) activity a...

متن کامل

Inhibition of carbamoyl-phosphate synthase (ammonia) by Tris and Hepes. Effect on Ka for N-acetylglutamate.

The apparent Ka for N-acetylglutamate of rat liver carbamoyl-phosphate synthase is 11 microM in phosphate buffer, a value 10-fold lower than reported in other buffer systems. Tris and Hepes inhibit competitively with N-acetylglutamate. The proportion of carbamoyl-phosphate synthase in the active enzyme-acetylglutamate complex in vivo may be higher than previous calculations suggest, which re-op...

متن کامل

Urea synthesis by ruminal epithelial and duodenal mucosal cells from growing sheep.

The objective was to determine whether ruminant gut tissues have the capability to synthesize urea in a short-term incubation. Mixed primary cell cultures containing ruminal epithelial (REC) or duodenal mucosal cells (DMC) were isolated from growing sheep (n = 4) fed a mixed forage-concentrate diet. Cells were incubated (90 min) in a Krebs salts-based buffer with either acetate (5 mM) or propio...

متن کامل

Role of carglumic acid in the treatment of acute hyperammonemia due to N-acetylglutamate synthase deficiency

N-acetylglutamate synthase (NAGS) deficiency is a rare inborn error of metabolism affecting ammonia detoxification in the urea cycle. The product of NAGS is N-acetylglutamate which is the absolutely required allosteric activator of the first urea cycle enzyme carbamoylphosphate synthetase 1. In defects of NAGS, the urea cycle function can be severely affected resulting in fatal hyperammonemia i...

متن کامل

Regulation of urea and citrulline synthesis under physiological conditions.

Information on the regulation of urea synthesis in vivo was obtained by examining the relationship between ureagenesis in vivo, citrulline synthesis in vitro, and two factors currently hypothesized to exert short-term regulation of this pathway: the liver mitochondrial content of N-acetylglutamate (NAG) and substrate availability. Rats meal-fed for 4 h every day (4-20 schedule) or for 8 h every...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • The Biochemical journal

دوره 218 3  شماره 

صفحات  -

تاریخ انتشار 1984