HISTOLOGY AND HISTOPATHOLOGY

Cellular and Molecular Biology

Immunohistochemical localization of truncated midkine in developing human bile ducts

M. Kato1, T. Shinozawa2, S. Kato3 and T. Terada4

1Second Department of Pathology, Faculty of Medicine, Tottori University, Yonago, Japan, 2Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, Kiryu, Japan, 3Division of Neuropathology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan and 4Department of Pathology, Shimizu Municipal Hospital, Shimizu, Japan

Offprint requests to: Masako Kato, M.D., Ph.D., Second Department of Pathology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago 683-8503, Japan. Fax: +81-859-34-8348. e-mail: makato@grape.med.tottori-u.ac.jp

 

Summary. Midkine (MK) is a heparin-binding growth factor whose gene has been identified in embryonal carcinoma cells in early stages of retinoic acid-induced differentiation. In the present study, we investigated the developmental localization of truncated MK protein in human bile ducts. Thirty specimens of the livers from 25 fetuses (from 9 to 40 gestational weeks) and from five neonates less than 4 weeks old were examined. Immunohistochemical analysis was performed using a mouse IgG2b monoclonal antibody against recombinant-truncated MK. Truncated MK was expressed moderately in the fetal liver from 9 to 15 gestational weeks. The immunoreactivities were found in the primitive hepatocytes, ductal plates, migrating biliary cells and immature bile ducts. The reaction products were localized in the cytoplasm heterogeneously. The intensity of immunostaining was weak from 15 gestational weeks to 26 gestational weeks. After 27 gestational weeks, truncated MK was not detected in the fetal livers. It was suggested that primitive hepatocytes, ductal plates and immature bile ducts produced truncated MK transiently during human bile ducts development. Histol. Histopathol. 18, 129-134 (2003)

Key words: Midkine, Truncated midkine, Fetus, Bile duct, Immunohistochemistry

DOI: 10.14670/HH-18.129