Project/Area Number |
01870036
|
Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
|
Allocation Type | Single-year Grants |
Research Field |
Gastroenterology
|
Research Institution | Osaka University |
Principal Investigator |
FUSAMOTO Hideyuki Osaka University Medical School Lecturer, 医学部, 講師 (90124776)
|
Co-Investigator(Kenkyū-buntansha) |
KATAYAMA Kazuhiro Osaka University Hospital Staff, 医学部附属病院, 医員
SASAKI Yutaka Osaka University Medical School Assistant, 医学部, 助手
KASAHARA Akinori Osaka University Medical School Assistant, 医学部, 助手 (70214286)
HAYASHI Norio Osaka University Medical School Lecturer, 医学部, 講師 (00144478)
|
Project Period (FY) |
1989 – 1990
|
Project Status |
Completed (Fiscal Year 1990)
|
Budget Amount *help |
¥9,800,000 (Direct Cost: ¥9,800,000)
Fiscal Year 1990: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1989: ¥6,200,000 (Direct Cost: ¥6,200,000)
|
Keywords | Gene expression / Proto-oncogene / DNA / PKC |
Research Abstract |
In order to clarify gene expressions in small specimen of liver tissue, we examined the expression of proto-oncogene and protein Kinase C (PKC) during liver regeneration. In this study, an in situ hybridyzation technique was applied for analysis. The role of proto-oncogenes in cell transformation ha been firmly established by both genetic and biochemical studies, but little is known about the role of these proto-oncogenes in normal cellular processes. Further, PKC plays a crucial role in signal transduction for a variety of biologically active substances which trigger cellular functions and proliferation. Expression of the c-Ha-ras proto-oncogene is specifically enhanced during liver regeneration, in parallel with increased DNA replication. In normal rat liver, a few hepatocytes expressed the mRNAs and the corresponding proteins without any preferential localization. Zonal heterogeneity of c-Ha-ras gene expression first became evident at 12 hr after CC14 administration, a higher number of gene products being detected in the pericentral zone than in the periportal zone. This heterogeneity became maximal at 24 hr after CC14 administration. The protein kinase C alpha subspecies was activated in a heterogeneous fashion, a higher number of hepatocytes expressing the protein kinase C alpha subspecies being detected in the pericentral zone than in the periportal zone. This zonal heterogeneity became maximal at 24 hr after the treatment. The distribution of hepatocytes expressing the protein kinase C alpha subspecies was roughly coincident with that of hepatocytes exhibiting of DNA synthesis. These results suggest that c-Ha-ras and protein kinase C may play a crucial role in liver regeneration.
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