Periportal Distribution of Diethylnitrosamine-Induced Gamma-GTP Positive Foci in the Liver of Sprague-Dawley Rat

Kim, Hong Joo; Lee, Soong Hwan; Back, In Gyu; Gham, Chang Woo; Park, Dong Il; Jung, Cheol Hun; Jo, Yong Hyeon; Nam, Seung Woo; Lee, Dong Hoo

Abstract

BACKGROUNR/AIMS: Heterogeneity of liver cell populations within the hepatic lobules can affect xenobiotic reaction. In this study, we attempt to clarify the stereological distribution of the y-GTP positive foci in hepatic lobule initiated by diethylnitrosamine and promoted by phenobarbital.
METHODS
/METERIALS: To the five Sprague-Dawley rats, one day after birth, diethylnitrosamine (0.15 pmole/pn) was intraperitoneally injected and by the weaning at four weeks of life, 0.035% phenobarbital in drinking water was fed for four weeks, at which time the rats were sacrified to obtain the livers. Livers were fixed in fresh cold ethanol acetic acid. Ihe 200 cotmecutive tissue sections were stained by histochemistry for y-GIP and countastained with toluidine blue ar HkE. Employing Zeiss microprojector, y-GTP foci wae traced. And then the largest cross-sectian (size class: 65-165 pm in diameter) of 52 y-GTP foci were selected. Using microscopic grid, distances fiom center of y-GlP foci to nearest centtal vein and bile ductule was measured. As a control group, out of 52 random points determined by rareken digit table, the distances were measured by the same romr. RESULT: the diameter Aom the central points of y-GIP positive foci to the neatest bile ductules was measured as 0.234620+0.14899mm (mean+SD) and the diameter from random points to the neatest bile ductules was measured as 0.303080+0.19582mm (mean+SD). Y-GTP positive foci located within 0.3mm diameter fram bile ductules were counted as 73.1% of 52 foci, whereas that of random points were only 55.8%. Accoring to Aequency table analysis by Shapiro-Wilk W test, there was significant difference by W-value (0.812065) and p-value (0.0144866).
CONCLUSION
Stereologically, y -GTP positive foci initiated by diethylnitros;unine, promoted by phaxkarbital in neonatal Spague-Dawley rats were non-rarxlanly distributed in peripcetal atea (Rappaport zone I) in hepatic lobule during hepatocarcinogenesis.