The effect of La^(3+) on formation of osteoclast-like cells in rabbit bone marrow cells induced by 1,25-dihydroxyvitamin D_3 and their bone-resorbing activity was evaluated by counting the number of tartrate resistant...The effect of La^(3+) on formation of osteoclast-like cells in rabbit bone marrow cells induced by 1,25-dihydroxyvitamin D_3 and their bone-resorbing activity was evaluated by counting the number of tartrate resistant-acid phosphatase-positive [TRAP(+)] multi-nucleated cells and measuring the number and surface area of bone resorption pits with photomicrography and image analysis. The formation and morphological characteristics of osteoclast-like cells and bone resorption pits were observed under a phase contrast inverted microscope. La^(3+) promotes the formation of osteoclast-like cells at the concentration of 1.00×10^(-8)mol·L^(-1) compared with the control group(P<(0.01)), whereas no significant change in cell number is observed at higher concentrations(1.00×10^(-5), (1.00×)10^(-6) and 1.00×10^(-7) mol·L^(-1))(P>0.05). La^(3+) at the concentration of 1.00×10^(-8)mol·L^(-1) also increases the number and surface area of the resorption pits(P<0.01), but inhibits the bone-resorbing activity dose-dependently(P<0.01)at higher concentrations(1.00×10^(-5), 1.00×10^(-6) and 1.00×10^(-7) mol·L^(-1)). These findings suggest that La^(3+) may promote or inhibit the formation and bone-resorbing activity of osteoclast-like cells depending on its concentration.展开更多
The effect of lanthanum （ Ⅲ ） （La^3 ＋ ） on cytosolic free calcium （ [ Ca^2 ＋ ] i ） in isolated rabbit mature osteoclasts was studied with the employment of fluo-3/AM as an intracellular calcium-sensitive fluo...The effect of lanthanum （ Ⅲ ） （La^3 ＋ ） on cytosolic free calcium （ [ Ca^2 ＋ ] i ） in isolated rabbit mature osteoclasts was studied with the employment of fluo-3/AM as an intracellular calcium-sensitive fluorescent probe by using a confocal laser scanning microscope. La^3＋ does not alter basal [Ca^2＋ ]i levels and cell spread area at the concentration of 1.00 × 10^- 8 mol· L ^- 1. However, La^3 ＋ at higher concentrations （ 1. 00 × 10^ - 5 and 1.00 × 10^- 7 mol· L^- 1 ） decreases [ Ca^2 ＋ ] i levels and cell spread area, and greater decreases are observed for the higher concentrations of La^3 ＋ . Since [Ca^2 ＋ ]i affects cytoskeleton and the adhesion properties of osteoclasts, our results seem to suggest that La^3 ＋ inhibit bone resorption by decreasing [Ca^2＋]i in rabbit mature osteoclasts.展开更多
The effects of lanthanum （Ⅲ） on the bone resorbing activity of rabbit mature osteoclasts （OCs） in the presence of osteoblasts （OBs） were studied in vitro by measuring the number and area of absorption pits. La...The effects of lanthanum （Ⅲ） on the bone resorbing activity of rabbit mature osteoclasts （OCs） in the presence of osteoblasts （OBs） were studied in vitro by measuring the number and area of absorption pits. La（ Ⅲ ） at concentrations ranging from 1.00 × 10^-5 to 1.00 × 10^-8 mol·L^-1 show no effect on mature OC number （P 〉 0.05）. In the OC-OB coculture systems without La（Ⅲ ）, osteoblasts alone did not influence the pit number and area whether the two kinds of cells were in contact or not （ P 〉 0.05）. Under the OC-OB not-in-contact condition, the effect of La（ Ⅲ ） on the bone-resorbing activity of OCs was similar to that of La（Ⅲ） in the absence of OBs （P 〉 0.05）. However, while OCs were in direct contact with OBs, the inhibitory effects of La（ Ⅲ ） on OCs＇ bone-resorbing activity decreased at the concentrations of 1.00 × 10^-5, 1.00×10^-6 and 1.00×10^-7mol·L^-1, and the promotion effects increased at 1.00×10^-8mol·L^-1 （P 〈0.05）. The results suggest that direct cell-cell contact between OC and OB be essential for OBs to play their role in regulating the response of OCs to La（ Ⅲ ）.展开更多
文摘The effect of La^(3+) on formation of osteoclast-like cells in rabbit bone marrow cells induced by 1,25-dihydroxyvitamin D_3 and their bone-resorbing activity was evaluated by counting the number of tartrate resistant-acid phosphatase-positive [TRAP(+)] multi-nucleated cells and measuring the number and surface area of bone resorption pits with photomicrography and image analysis. The formation and morphological characteristics of osteoclast-like cells and bone resorption pits were observed under a phase contrast inverted microscope. La^(3+) promotes the formation of osteoclast-like cells at the concentration of 1.00×10^(-8)mol·L^(-1) compared with the control group(P<(0.01)), whereas no significant change in cell number is observed at higher concentrations(1.00×10^(-5), (1.00×)10^(-6) and 1.00×10^(-7) mol·L^(-1))(P>0.05). La^(3+) at the concentration of 1.00×10^(-8)mol·L^(-1) also increases the number and surface area of the resorption pits(P<0.01), but inhibits the bone-resorbing activity dose-dependently(P<0.01)at higher concentrations(1.00×10^(-5), 1.00×10^(-6) and 1.00×10^(-7) mol·L^(-1)). These findings suggest that La^(3+) may promote or inhibit the formation and bone-resorbing activity of osteoclast-like cells depending on its concentration.
文摘The effect of lanthanum （ Ⅲ ） （La^3 ＋ ） on cytosolic free calcium （ [ Ca^2 ＋ ] i ） in isolated rabbit mature osteoclasts was studied with the employment of fluo-3/AM as an intracellular calcium-sensitive fluorescent probe by using a confocal laser scanning microscope. La^3＋ does not alter basal [Ca^2＋ ]i levels and cell spread area at the concentration of 1.00 × 10^- 8 mol· L ^- 1. However, La^3 ＋ at higher concentrations （ 1. 00 × 10^ - 5 and 1.00 × 10^- 7 mol· L^- 1 ） decreases [ Ca^2 ＋ ] i levels and cell spread area, and greater decreases are observed for the higher concentrations of La^3 ＋ . Since [Ca^2 ＋ ]i affects cytoskeleton and the adhesion properties of osteoclasts, our results seem to suggest that La^3 ＋ inhibit bone resorption by decreasing [Ca^2＋]i in rabbit mature osteoclasts.
基金Project supported bythe National Natural Science Foundation of China (20031010 ,20271005)
文摘The effects of lanthanum （Ⅲ） on the bone resorbing activity of rabbit mature osteoclasts （OCs） in the presence of osteoblasts （OBs） were studied in vitro by measuring the number and area of absorption pits. La（ Ⅲ ） at concentrations ranging from 1.00 × 10^-5 to 1.00 × 10^-8 mol·L^-1 show no effect on mature OC number （P 〉 0.05）. In the OC-OB coculture systems without La（Ⅲ ）, osteoblasts alone did not influence the pit number and area whether the two kinds of cells were in contact or not （ P 〉 0.05）. Under the OC-OB not-in-contact condition, the effect of La（ Ⅲ ） on the bone-resorbing activity of OCs was similar to that of La（Ⅲ） in the absence of OBs （P 〉 0.05）. However, while OCs were in direct contact with OBs, the inhibitory effects of La（ Ⅲ ） on OCs＇ bone-resorbing activity decreased at the concentrations of 1.00 × 10^-5, 1.00×10^-6 and 1.00×10^-7mol·L^-1, and the promotion effects increased at 1.00×10^-8mol·L^-1 （P 〈0.05）. The results suggest that direct cell-cell contact between OC and OB be essential for OBs to play their role in regulating the response of OCs to La（ Ⅲ ）.
