Abstract
1. 1. The nodular phase of hepatic premalignancy was induced in male Fischer 344 rats by the administration of diethylnitrosamine, 200 mg/kg i.p., followed by promotion utilizing the Solt-Farber promoting regime. 2. 2. Relative to the situation in normal non-treated control rats: the activity of γ-glutamyltranspeptidase was found to be increased 9.42-fold in homogenate and 7.33-fold in plasma membrane fractions prepared from the livers of saline-injected control rats; and 81.37-fold in homogenates and 91.92-fold in plasma membranes prepared from the livers of diethylnitrosamine-injected rats; plasma levels of total T 3 and total T 4 were found to be decreased 42.06 and 47.45% in saline-injected control rats and 88.7 and 83.2% in diethylnitrosamine-injected rats, respectively. 3. 3. An early pre-nodular phase of hepatic premalignancy was produced in young immature and mature adult male Fischer 344 rats by the administration of diethylnitrosamine, 75 mg/kg, without subsequent application of the promotion regime. 4. 4. Relative to the situation in control rats: the activity of γ-glutamyltranspeptidase was found to be increased in liver homogenates prepared from diethylnitrosamine-treated rats, 1.62-fold in young immature rats 1.20-fold in mature adult rats; plasma levels of total T 3 were found to be reduced in diethylnitrosamine-treated rats, 28% in young immature rats 9% in mature adult rats. 5. 5. Treatment of diethylnitrosamine-injected young immature male Fischer 344 rats at the prenodular phase of hepatic premalignancy with tri-iodothyronine at 0.005 μg/kg s.c. daily for 7 days reversed the diethylnitrosamine-induced increase in liver homogenate γ-glutamyltranspeptidase activity and the decrease in plasma total T 3, restoring these parameters to normal levels. 6. 6. Thyroid hormone deficiency as a major contributor to the diethylnitrosamine-induced increase in γ-glutamyltranspeptidase at the premalignant phase of hepatocarcinogenesis is discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
