title: Cytological and quantitative cytochemical changes in the hepatocyte population of newborn rats following hydrocortisone administration.
abstract: Changes have been assessed in cytological and quantitative cytochemical parameters of the hepatocyte population of newborn rats under glucocorticoid stimulation. Administration of hydrocortisone-acetate at the dose of 25 micrograms/g b.w./d during the 2nd week of postnatal life, caused: 1. an increase of the liver weight and of average dry mass, protein content, and volume of the hepatocytes; 2. a decrease of the number of hepatocytes per mg of liver tissue; 3. a reduction of the mitotic activity in liver parenchyma; 4. a gain in number of hepatocytes per liver lower than under normal conditions; 5. an increase of frequency of binuclear cells; 6. an increase of DNA-Feulgen per hepatocyte nucleus; 7. an increase per cell, greater than the mean protein increase per cell, in activity of arylhydrocarbonmonooxygenase and 7-ethoxycoumarin 0-deethylase, 2 enzymes dependent on cytochrome P-450. Induction of arylhydrocarbonmonooxygenase activity was prevalent in centrolobule. All the examined parameters, except that of DNA-Feulgen per nucleus and that of mitotic activity, changed strictly correlated with the duration of hormonal treatment. The values of a number of hepatocyte parameters (particularly: mean cell dry mass and volume, frequency of binuclear cells, enzymic activity) detected in the 12 d old rats after a 5 d long hormonal pretreatment, were in the range of those of animals 1 to 2 weeks older.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002452:Cell Count; D002467:Cell Nucleus / Q000032:analysis; D004247:DNA / Q000032:analysis; D003720:Densitometry; D006651:Histocytochemistry; D006854:Hydrocortisone / Q000031:analogs & derivatives* / Q000494:pharmacology; D008099:Liver / Q000033:anatomy & histology / Q000166:cytology / Q000187:drug effects*; D008856:Microscopy, Fluorescence; D008940:Mitotic Index; D009929:Organ Size; D011506:Proteins / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D011506:Proteins; C021650:hydrocortisone acetate; D004247:DNA; D006854:Hydrocortisone