Protein phosphorylation in isolated hepatocytes of septic and endotoxemic rats

Journal Article · Wed Nov 01 04:00:00 EST 1989 · American Journal of Physiology; (USA)

OSTI ID:5035579

Deaciuc, I V; Spitzer, J A ^[1]

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1. Louisiana State Univ. Medical Center, New Orleans (USA)

The purpose of this study was to investigate possible alterations induced by sepsis and endotoxicosis in the late phase of Ca2+-dependent signaling in rat liver. Hepatocytes isolated from septic or chronically endotoxin (ET)-treated rats were labeled with (32P)H3PO4 and stimulated with various agents. Proteins were resolved by one-dimensional polyacrylamide gel electrophoresis and autoradiographed. Vasopressin (VP)- and phenylephrine (PE)-induced responses were attenuated in both septic and ET-treated rats for cytosolic and membrane proteins compared with their respective controls. Glucagon and 12-O-myristate phorbol-13-acetate (TPA) affected only the phosphorylation of membrane proteins. Glucagon-induced changes in the phosphorylation of membrane proteins were affected by both sepsis and endotoxicosis, whereas TPA-stimulated phosphorylation was lowered only in endotoxicosis. Response to the Ca2+ ionophore A23187 was depressed in septic rats for cytosolic proteins. The phosphorylation of two cytosolic proteins, i.e., 93 and 61 kDa (previously identified as glycogen phosphorylase and pyruvate kinase, respectively), in response to VP, PE, and A23187 was severely impaired by endotoxicosis and sepsis. TPA did not affect the phosphorylation state of these two proteins. The results show that sepsis and endotoxicosis produce perturbations of the phosphorylation step in Ca2+ transmembrane signaling. Such changes can explain alterations of glycogenolysis and gluconeogenesis associated with sepsis and endotoxicosis.

• OSTI ID: 5035579
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 257; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
560300 -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
ANTIGENS
ATP
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CARCINOGENS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ELECTROPHORESIS
ENDOTOXINS
ESTERS
HORMONES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIVER CELLS
MAMMALS
MATERIALS
MEMBRANES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PHORBOL ESTERS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORYLATION
PITUITARY HORMONES
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SOMATIC CELLS
TOXIC MATERIALS
TOXINS
TRACER TECHNIQUES
VASOPRESSIN
VERTEBRATES