Changes in protein sulfur groups in hepatocytes of newborn rats under glucocorticoid stimulation.
A daily administration of hydrocortisone-acetate (25 micrograms/g b.w.) increased both dry mass and protein content of the hepatocytes of newborn rats by 84% and 89% respectively, after 5-day-treatment. The increase correlated with the duration of hormonal treatment. As an average per cell, the total reactive protein sulfur increased up to 127%. This increase depends on a major increment of thiols (+179%) and on a minor increment of disulfides (+18%). Within the thiols, the fast reactive ones exhibited the most pronounced increment (+214%). Per protein unit, the total reactive sulfur increased, after a 1 day lag period, by up to +20%. Thiols showed a 47%-increment due to increase of fast reactive thiols (+70%) more than of slow reactive thiols (+20%). On the contrary, disulfides decreased (-37%). Consequently, the protein thiol/disulfide ratio shifted from 2.14 in control hepatocytes to 4.98 (+133%) in hormone-stimulated hepatocytes. Both the increase of the thiol content, and the shift of the SH/SS-equilibrium of the cellular proteins, correlated with a concomitant increase of enzymic activities such as gamma-glutamyltranspeptidase, glutathione reductase, glutathione peroxidase, glutathione S-transferase and 7-ethoxycoumarin O-deethylase.
Istituto di Patologia Generale, Università degli Studi di Pisa, Scuola Medica, Italy.
R
R
Tongiani
A
A
Paolicchi
G
G
Nöhammer
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D004220:Disulfides / Q000378:metabolism*; D006854:Hydrocortisone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013997:Time Factors
D004220:Disulfides; D011506:Proteins; D013438:Sulfhydryl Compounds; C021650:hydrocortisone acetate; D006854:Hydrocortisone