An experiment was designed to study the efficacy of the combined administration of the nilvadipine as a calcium channel blocker which was estimated less toxic for heart. As for SCC-25 cells, KB cells and Hela cells, the effect of the combination of nilvadipine and 5'-DFUR was tested in vitro.
Furthermore, each cell was stained immunohistochemically by ABC method and efficacy brought about by the combined administration of nilvadipine as a chemosensitizer was investigated.
At the same time, each cell was studied from the view point of correlation with P-glycoprotein. As for SCC-25 cells, having incubated 48 hours, significantly additive effects in combination of 0.1μ gml-1 of nilvadipine and 16μ gml-1 of 5'-DFUR were recognized statistically (examination-I). KB cells showed the additive effect, but were not significant statistically.
On the other hand, the immunohistochemical stain by ABC method was performed on SCC-25 and KB cells and it turned out that P-glycoprotein was positive.
For further additive effects for 5'-DFUR by nilvadipine, it was indicated that the mechanism had been correlated with P-glycoprotein
