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Suppressive effects of estradiol on dimethylnitrosamine‐induced fibrosis of the liver in rats
Author(s) -
Yasuda Mitugi,
Shimizu Ichiro,
Shiba Masako,
Ito Susumu
Publication year - 1999
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.510290307
Subject(s) - hepatic stellate cell , medicine , endocrinology , hepatic fibrosis , fibrosis , procollagen peptidase , lipid peroxidation , malondialdehyde , chemistry , biology , oxidative stress
Abstract As a model for the analysis of the fibrosuppressive role of estradiol, hepatic fibrosis was induced in male and female rats by the administration of a single dose of dimethylnitrosamine (DMN). The fibrotic response of the male liver after DMN treatment was significantly stronger than that of the female liver. In the male DMN model, estradiol reduced hepatic mRNA for type I and III procollagens and the tissue inhibitor of metalloproteinase‐1 (TIMP‐1), as well as deposition of type I and III collagen protein total hepatic collagen and malondialdehyde (MDA), a product of lipid peroxidation. Concomitant administration of a neutralizing antibody against rat estradiol enhanced fibrogenesis, as judged by the same parameters. Ovariectomy in the female model had a fibrogenic effect, inducing the hepatic expression of both types of procollagen and TIMP‐1; in addition, the number of α‐smooth muscle actin (α‐SMA)–positive cells in the liver increased; estradiol replacement was fibrosuppressive in the castrated‐female model. In rat hepatic stellate cells incubated in primary culture with estradiol, cell number, type I collagen production, and α‐SMA expression were all reduced. These findings suggest that estradiol suppressed the induction of hepatic fibrosis, and may in part underlie the more rapid progression in males of hepatic fibrosis and its complications.