Inheritance of androgen program of male-specific expression of unusual estrogen-binding protein by daughter hepatocytes at rat liver regeneration.
A possibility of inheritance of androgen and basic genetic programs at the level of unusual estrogen-binding protein (UEBP) by daughter hepatocytes was investigated. Liver regeneration after partial (2/3) hepatectomy or after selective poisoning of hepatocytes of the central zone of hepatic lobules with CCl4 in adult rats were used as models of total and zonal proliferation of hepatocytes, respectively. UEBP content and the pattern of its tissue expression in the course of liver regeneration were monitored by radioligand and immunocytochemical technique. In animals of all groups possessing the androgen program of UEBP expression (intact, castrated and/or hypophysectomized males, and ovariectomized females treated with androgen) UEBP content was shown to be similarly high before initiation and after completion of liver regeneration. Unlike in males, in androgenized females a transient 4-fold increase of UEBP concentration on day 4 after partial hepatectomy was observed. In animals with a basic genetic program at the level of this protein (ovariectomized females, neonatally castrated males) only trace amounts of UEBP were observed in intact as well as in regenerated liver. The data were confirmed by immunocytochemical technique. A gradient mode of distribution of UEBP-contained cells within hepatic lobules with the highest specific staining around central veins was found by immunocytochemical technique in males. Specific staining of centrolobular and periportal hepatocytes was 7- to 10-fold in intact, and 4- to 6-fold in castrated and/or hypophysectomized males. In intact females specific staining was distributed uniformly at extremely low levels similar to that in periportal hepatocytes of males. Androgen administration to ovariectomized females stimulated a significant and stable increase of UEBP content in two layers of hepatocytes surrounding the central vein. Profiles of specific staining of hepatocytes within the hepatic lobules similar to that in control animals were observed after the completion of liver regeneration of different groups of rats. The results obtained suggest all the hepatocytes to be targets for androgen programming, natural in males or experimental in females, while the extent of expression of this program depends on the position of a hepatocyte within the liver lobules and the sex of the animal.
Smirnova
O V
OV
Laboratory of Endocrinology, School of Biology, Moscow M. V. Lomonosov State University.
Kovtun
I V
IV
Smirnov
A N
AN
Shchelkunova
T A
TA
Factor
V M
VM
Rozen
V B
VB
D000728:Androgens / Q000235:genetics*; D000818:Animals; D002251:Carbon Tetrachloride; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D002369:Castration; D005260:Female; D006498:Hepatectomy; D007124:Immunoenzyme Techniques; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008115:Liver Regeneration / Q000235:genetics; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011960:Receptors, Estrogen; D012727:Sex Characteristics
D000728:Androgens; D002352:Carrier Proteins; D011960:Receptors, Estrogen; C010140:estrophilin; D002251:Carbon Tetrachloride