2012 Volume 33 Issue 2 Pages 105-112
Abstract : In the present study, we examined the effect of heat stimulation on a rat clonal odontoblast-like cell line (KN-3) under the under-nutrition condition. KN-3 was cultured with medium containing 10% (for normal condition) or 1% (for under-nutrition condition) fetal bovine serum, and exposed to heat stimulation at 43°C for 45 minutes. Cell proliferation was assessed by MTS assay and cell apoptosis was determined by TUNEL staining. We also evaluated the alkalinephosphatase (ALP) activity and expression of dentin sialoprotein (DSP) and dentin matrix protein-1 (DMP-1). Increase of apoptotic cells and decrease of total cell number were observed after heat stimulation, and these phenomena were markedly enhanced under the under-nutrition condition. By day 3 after heat stimulation, the expression of DSP and DMP-1 was maintained even under the under-nutrition condition. On the other hand, the ALP activity tended to decrease under the under-nutrition condition by day 7 after heat stimulation. These results indicate that cell damage including apoptosis by heat was severe under the under-nutrition condition, and some odontoblast functions such as ALP activity were depressed under the under-nutrition condition. However, their odontoblast properties were resistant to heat stimulation under the under-nutrition condition.
