Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.4.1.2 (
glutamate dehydrogenase
)
4,380
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Recently, cases of liver damage and liver tumors have been reported after treatment of prostate cancer patients with the antiandrogen cyproterone acetate (CPA). In rat liver, CPA initiates a wave of DNA synthesis that is accompanied by apoptosis. In apoptotic hepatocytes, a latent form of transforming growth factor beta 1 (
TGF-beta
1) is detectable by immunohistochemistry. Injection of a single dose of
TGF-beta
1 induces apoptosis in the liver of animals pretreated with CPA but has an insignificant effect in untreated animals. In this study, we show by Northern analysis that there is increased expression of
TGF-beta
1 in the liver after CPA treatment. Detection of
TGF-beta
1 with in situ hybridization showed that
TGF-beta
1 was synthesized in the parenchymal cells. Time course and dose-response experiments performed 48 hours after the last application of CPA showed that apoptotic nuclei with chromatin condensed at the nuclear periphery (AN) were already visible 2 hours after injection (0.13%), and apoptotic bodies (ABs) increased 2 to 9 hours after the injection (from 1.28% to 6.67%) after 25 micrograms
TGF-beta
1/kg. At 4.5 hours after injection, an induction of apoptosis could be detected with 0.25 microgram
TGF-beta
1/kg and after the maximum dose (250 micrograms
TGF-beta
1/kg) ANs (0.24%) and ABs (16.74%) were homogeneously distributed throughout the liver lobe. Irrespective of the dose or time after injection of
TGF-beta
1, 82% of the ABs were localized within hepatocytes. Liver enzymes were detected in high amounts in the serum (eightfold elevation of
glutamate dehydrogenase
, fivefold elevation of alanine transaminase [ALT]) 7 hours after the first visible sign of apoptosis. After an additional 20 hours, the liver contained many necrotic figures. These results suggest that the combination of
TGF-beta
1 expression coupled with a strikingly enhanced sensitivity to the induction of apoptosis could be responsible both for the liver damage and the development of liver tumors observed after treatment with CPA.
...
PMID:The antiandrogen cyproterone acetate induces synthesis of transforming growth factor beta 1 in the parenchymal cells of the liver accompanied by an enhanced sensitivity to undergo apoptosis and necrosis without inflammation. 859 60
