... of Dentistry, Osaka University, 1-8, Yamadaoka, Suita, Osaka 565, Japan; and §Chugai Pharmaceutical. Co., 3-41-8, Takada, Toshima-ku, Tokyo 171, Japan.
Proc. Nati. Acad. Sci. USA Vol. 87, pp. 6522-6526, September 1990 Biochemistry
Role of 1,25-dihydroxycholecalciferol in growth-plate cartilage: Inhibition of terminal differentiation of chondrocytes in vitro and in vivo YUKIO KATO*t, ATSUSHI SHIMAZU*, MASAHIRO IWAMOTOt, KAZUHISA NAKASHIMA*, TATSUYA KoIKE*, FunIo SUZUKI*, YASUHO NISHII§, AND KATSUHIKO SATO§ Departments of *Biochemistry and *Radiology, Faculty of Dentistry, Osaka University, 1-8, Yamadaoka, Suita, Osaka 565, Japan; and §Chugai Pharmaceutical Co., 3-41-8, Takada, Toshima-ku, Tokyo 171, Japan
Communicated by H. A. Barker, June 4, 1990
ABSTRACT The effects of vitamin D metabolites on alkaline phosphatase [ALPase; orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] activity, a marker ofterminal differentiation, in chondrocyte cultures and growth plates in vivo were examined. In cultures of pelleted rabbit growth-plate chondrocytes, 1,25-dihydroxycholecalciferol (1,25-dihydroxyvitamin D3) increased the contents of DNA and macromolecules containing uronic acid (proteoglycans). It also decreased ALPase activity with an ED50 of
