PT  - JOURNAL ARTICLE
AU  - C O Brostrom
AU  - S B Bocckino
AU  - M A Brostrom
AU  - E M Galuska
TI  - Regulation of protein synthesis in isolated hepatocytes by calcium-mobilizing hormones.
DP  - 1986 Jan 01
TA  - Molecular Pharmacology
PG  - 104--111
VI  - 29
IP  - 1
4099  - http://molpharm.aspetjournals.org/content/29/1/104.short
4100  - http://molpharm.aspetjournals.org/content/29/1/104.full
SO  - Mol Pharmacol1986 Jan 01; 29
AB  - The incorporation of leucine into protein was studied in Ca2+-depleted and Ca2+-restored preparations of normal liver cells isolated from fed, adult male rats. Ca2+-restored cells incorporated amino acid 5-10-fold more rapidly than did Ca2+-depleted cells for incubation periods up to 1 hr. Readdition of Ca2+ at supraphysiologic concentrations (3 mM) to depleted cells restored the rate of incorporation within 8-10 min, whereas lesser concentrations of the cation acted more slowly. Vasopressin and alpha-adrenergic agonists rapidly (in minutes) inhibited amino acid incorporation to variable degrees in liver cells, with pronounced inhibitions (40-75%) occurring at moderate (0.1-1 mM) extracellular Ca2+ concentrations and smaller inhibitions (10-30%) occurring at supraphysiologic concentrations of the cation. Hormonally produced inhibitions were more intense at acid pH than at alkaline pH. The effects of epinephrine were mediated through alpha 1-adrenergic receptors and were not additive with those of vasopressin at saturating concentrations. It is proposed that these hormones, which are known to mobilize sequestered Ca2+ within liver cells, inhibit amino acid incorporation by influencing a Ca2+ requirement associated with protein synthesis.