Figure 6. Effects of κ-OR stimulation on β-GP-induced mineralization in aortic rings from rats. (A) Representative Alizarin red-stained sections of aortic rings from rats; Scale bar = 500 μm (above panel) and 100 μm (below panel). (B) Quantification of mineralization in the aortic rings using the O-cresol phthalein complex one assay. Aortic rings from rats were incubated in control medium (Con; serum-free DMEM), phosphate medium (β-GP; serum-free DMEM + 10 mmol/L β-GP), phosphate medium + U50,488H (40 mmol/L), or phosphate medium + nor-BNI (80 mmol/L) + U50,488H (40 mmol/L) for ten days. U, U50,488H; β-GP, β-Glycerophosphate disodium salt pentahydrate; N, nor-BNI; Data are shown as mean ± SEM and were analyzed using one-way ANOVA tests. n = 4 in each group. *P < 0.05 versus the control group, #P < 0.05 versus the β-GP group, $P < 0.05 versus the β-GP+U group.