The level of MAP kinase activity in the stomach stump in rats after subtotal gastrectomy.
Banasiewicz T. Marciniak R. Majewski P. Biczysko M. Drews M.
Clinic of Surgery, Karol Marcinkowski University School of Medical Sciences, Poznan, Poland.
MAPK (Mitogen-Activated Protein Kinase) is one of the elements of kinase cascades (MAPK, MEK-MAP kinase, kinase, Raf-1, Ras) regulating cellular proliferation and differentiation processes. It seems that the changes in its number and activity may be the factor having influence on carcinogenesis. In some human carcinomas a significant increase of its activity is observed, in others a decrease of its activity is described. Our research aimed at the evaluation of the dynamics of precancerous and cancerous changes in the stomach stump in rats after the experimental, partial stomach resection. Apart from histological and ultrastructural examination we also determined the activity of the sub-unit p42 MAP kinase. The material comprised segments of gastric mucosa of the stomach stump of 15 rats after subtotal gastrectomy. Part of the rats after the procedure were administered carcinogen orally (MNNG). On the histological and ultrastructural examination we used routine methods, the activity of MAP kinase was determined by western-blotting method with the use of IgG against MAPK p42, Santa Cruz #154). In 8 examined rats we observed the increase of MAP kinase activity. We established probable correlation (without statistical analysis, regarding miserly material) between the increase of MAPK activity and histological and ultrastructural changes. Among three cases diagnosed as adenoma tubulare in two we observed the increase of MAPK activity. A clear increase of this kinase was also present in the stomach stump of a rat, which was diagnosed as adenocarcinoma. On the basis of our research carried so far we think that the increase of the MAPK activity may be one of the causes of the neoplasm development. It seems important to obtain the confirmation of our results and to establish a possible usefulness of MAPK activity determination as a prognostic indicator in case of the neoplasm of stomach stump.