[The sensitivity of carcinogenic initiation effect of regenerated liver induced by diethylnitrosamine in rats].
OBJECTIVE
To compare the sensitivity of carcinogenic initiation effect of regenerated liver with normal liver induced by diethylnitrosamine (DEN) in rats.


METHODS
Experimental group was composed of rats that had 2/3 of their liver excised 8 weeks previously, normal rats were used as controls to study: (1) weight of their livers, conventional histological examination and 3H-TdR incorporation test; (2) a modified Solt-Farber carcinogenesis scheme was applied in order to detect the degree of carcinogenic initiation effect by stereologic study of GGT positive preneoplastic liver cell foci; (3) damage of DNA in hepatocytes were detected by in situ nick translation test after DEN treatment both in vivo and in primary cultured liver cells.


RESULTS
(1) the regenerative process in liver was completed by the end of the 8th post-operative week and no proliferation of hepatocytes was detected. (2) both the number and volume density of GGT positive foci in the experimental group were higher than those in control group. (3) DNA damage in hepatocytes of experimental group were more severe than in the control group.


CONCLUSIONS
Even after the regeneration process was completed, the regenerated liver still possessed higher sensitivity to carcinogenic initiation effect than normal liver, this sensitivity was related with the severity of DNA damage in hepatocytes of the regenerated liver after DEN attack.
Department of Pathology, Institute of Basic medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing 100005.
G
G
Han
J
J
Chen
L
L
Ding
D000818:Animals; D015197:Carcinogenicity Tests; D002478:Cells, Cultured; D004249:DNA Damage; D004052:Diethylnitrosamine; D006498:Hepatectomy / Q000379:methods; D008099:Liver / Q000166:cytology*; D008115:Liver Regeneration; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D004052:Diethylnitrosamine