Reversible inhibition of the nonrepinephrine induction of lactate dehydrogenase by cytochalasin B in rat glial C6 cells. [Rats]

Technical Report · Thu Jan 01 04:00:00 EST 1976

OSTI ID:7238685

Bennett, K; de Vellis, J

The induction of lactate dehydrogenase (LDH; EC 1.1.1.27) in rat glial C6 cells by a 24 hr treatment with 3 ..mu..M norepinephrine (NE) was inhibited 70 percent by the simultaneous addition of cytochalasin (CB; 5, 15, or 20 ..mu..g/ml of culture medium). Pretreatment of cells with CB did not increase the inhibition. CB added to the enzyme assay had no effect. Dimethyl sulfoxide, the solvent for CB, had no effect on LDH induction. Removal of CB from cells treated 24 hr with 25 ..mu..g/ml CB allowed maximal LDH induction, demonstrating that the effect of CB is fully reversible. CB had no effect on basal LDH levels and did not act as an inhibitor of general protein synthesis. Since CB did not modify the rate of degradation of LDH, it, therefore, appears to block LDH induction by selectively inhibiting its synthesis. CB had no effect on the transient (intracellular and extracellular) rise in cyclic AMP generated in response to NE treatment. CB was effective when added during the transcription phase (first 3 hours) but not the translation phase (after 3 hours) of LDH induction. Therefore, CB must inhibit one of the early events of the inductive process, e.g., protein kinase translocation, protein phosphorylation, or RNA synthesis and processing. The possible relation between the effect of CB or LDH induction and the disruption of microfilaments by CB is discussed.

• Research Organization: California Univ., Los Angeles (USA)
• OSTI ID: 7238685
• Report Number(s): UCLA-12-1102
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550500 -- Metabolism
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
AMP
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOSYNTHESIS
DEHYDROGENASES
DMSO
DRUGS
ENZYMES
HORMONES
INHIBITION
LACTATE DEHYDROGENASE
MAMMALS
NORADRENALINE
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDOREDUCTASES
PROTEINS
RATS
RODENTS
STEROID HORMONES
SULFOXIDES
SYMPATHOMIMETICS
SYNTHESIS
VERTEBRATES