[Intracellular calcium ion release stimulated by 1,25(OH)2D3 and influenced with mechanical pressure in mandibular condylar chondrocytes of rabbit].
OBJECTIVE
To investigate the intracellular calcium ion release and the system of calcium channel by 1,25 (OH)2D3 stimulus, and the effect of mechanical pressure on it in rabbit mandibular condylar chondrocytes (MCC) in vitro.


METHODS
In vitro cultured MCC from two-week-old New Zealand rabbits were incubated under 20 g/L heparin, 1 g/L procaine, continuous pressure of 90 kPa for 60 min and 360 min in a hydraulic pressure controlled cellular strain unit. With the Fluo-3/AM probe loaded, 1,25(OH)2D3 was added to the medium and then the intracellular calcium level was detected by a laser confocal scanning microscope.


RESULTS
Intracellular calcium concentration increased in MCC treated with 1,25(OH)2D3, 1,25(OH)2D3 and procaine, while it didn't change in heparin treated group. Calcium in group under continuous pressure of 90 kPa for 60 min was also increased, even higher than the group stimulated only with 1,25(OH)2D3. Intracellular calcium in group treated with continuous pressure of 90 kPa for 360 min showed no significant difference compared to the control and even decreased at the end of the recording period.


CONCLUSIONS
1,25(OH)2D3 could stimulate the intracellular calcium release channel of inositol triphosphate (IP3) receptor open in MCC in vitro and increases the level of intracellular calcium concentration. Pretreatment of definite mechanical pressure could modulate the sensitivity of IP3 channel to 1,25(OH)2D3 stimulus.
Zhang
Min
M
Dept. of Oral Anatomy and Physiology, College of Stomatology, Fourth Military Medical University, Xi'an 710032, China.
Wang
Mei-qing
MQ
Wang
Jing-jie
JJ
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008335:Mandibular Condyle / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D018613:Microscopy, Confocal; D011312:Pressure; D011817:Rabbits; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D013250:Steroid Hydroxylases / Q000494:pharmacology*
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D018160:Receptors, Cytoplasmic and Nuclear; D013250:Steroid Hydroxylases; C406322:vitamin D 1-alpha hydroxylase; D002118:Calcium