Glucagon infusion increases rate of purine synthesis de novo in rat liver

Journal Article · Tue Dec 01 04:00:00 EST 1987 · American Journal of Physiology; (USA)

OSTI ID:6906505

Itakura, Mitsuo; Maeda, Noriaki; Tsuchiya, Masami; Yamashita, Kamejiro ^[1]

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1. Univ. of Tsukuba, Ibaraki (Japan)

Based on the parallel increases of glucagon, the second peak of hepatic cAMP, and the rate of purine synthesis de novo in the prereplicative period in regenerating rate liver after a 70% hepatectomy, it was hypothesized that glucagon is responsible for the increased rate of purine synthesis de novo. To test this hypothesis, the effect of glucagon or dibutyryl cAMP infusion on the rate of purine synthesis de novo in rat liver was studied. Glucagon infusion but not insulin or glucose infusion increased the rate of purine synthesis de novo, which was assayed by ({sup 14}C)glycine or ({sup 14}C)formate incorporation, by 2.7- to 4.3-fold. Glucagon infusion increased cAMP concentrations by 4.9-fold and 5-phosphoribosyl-1-pyrophosphate concentrations by 1.5-fold in liver but did not change the specific activity of amidophosphoribosyltransferase or purine ribonucleotide concentrations. Dibutyryl cAMP infusion also increased the rate of purine synthesis de novo by 2.2- to 4.0-fold. Because glucagon infusion increased the rate of purine synthesis de novo in the presence of unchanged purine ribonucleotide concentrations, it is concluded that glucagon after infusion or in animals after a 70% hepatectomy is playing an anabolic role to increase the rate of purine synthesis de novo by increasing cAMP and 5-phosphoribosyl-1-pyrophosphate concentrations.

• OSTI ID: 6906505
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 253:6; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
AMP
ANIMALS
AROMATICS
AZAARENES
BIOSYNTHESIS
BODY
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
DIGESTIVE SYSTEM
FORMIC ACID
GLANDS
GLUCAGON
GLYCINE
HEPATECTOMY
HETEROCYCLIC COMPOUNDS
HORMONES
INFUSION
INSULIN
INTAKE
LABELLED COMPOUNDS
LIVER
MAMMALS
MEDICINE
MONOCARBOXYLIC ACIDS
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PEPTIDE HORMONES
PEPTIDES
PHYSIOLOGY
POLYPEPTIDES
PROTEINS
PURINES
RATS
RODENTS
SURGERY
SYNTHESIS
VERTEBRATES