EFFECT OF 1?,25-DIHYDROXYVITAMIN D_3 ON CYTOSKELETON,GAP JUNCTION INTERCELLULAR COMMUNICATION AND [Ca~(2+)]_i OF OSTEOBLASTS / 营养学报

ABSTRACT

Objective To study the effect of 1?,25-dihydroxyvitamin D3[1,25-(OH)2D3] on cytoskeleton,gap junction intercellular communication (GJIC) and intracellular Ca2+ ([Ca2+]i) in osteoblasts (OB) in vitro. Method OB were isolated from calvaria bone. After 20 min and after 24 h treated by 1,25-(OH)2 VD3 (0,10-9,10-8,10-7 mol/L),[Ca2+]i was evaluated. F-actin and GJIC were observed after 24 and 48 h incubation later. Results Compared with the control group,[Ca2+]i in all 1,25-(OH)2 D3 groups was increased significantly at 20 min. [Ca2+]i in 10-9 mol/L 1,25-(OH)2D3 group was the lowest at 24 h after treatment. OB in 10-8 and 10-7 mol/L 1,25-(OH)2D3 groups were flat,and stress fibers were formed. The expression of F-actin in control group and 10-9 mol/L 1,25-(OH)2D3 group was reduced at 48 h after treatment. Compared with the control group,GJIC was weakened very significantly after treated with 10-9 mol/L 1,25-(OH)2D3 at 48 h,but enhanced very significantly in the group with 10-8 and 10-7 mol/L. Conclusion Higher dosage of 1,25-(OH)2D3 can maintain the morphology of OB and stimulate the communication among OB,but lower dosage can inhibit it.