TY - JOUR
T1 - Effect of 1,25-dihydroxyvitamin D3 on cytosolic calcium in dispersed parathyroid cells
AU - Sugimoto, T.
AU - Ritter, C.
AU - Ried, I.
AU - Morrissey, J.
AU - Slatopolsky, E.
N1 - Funding Information:
Acknowledgments This work was supported by U. S. Public Health Service NIADDK grants AM-09976, AM-07126, DK 30178 and RR-00036. The authors express their appreciation to Dr. Milan Huskokovic from Hoffman-La Roche, Inc. for supplying the 1,25-(OH)2D3, 24,25-(OH)2D3 and 25-(OH)D3 for this study and Mrs. Patricia Shy for her assistance in the preparation of the manuscript.
PY - 1988
Y1 - 1988
N2 - We examined the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on cytosolic calcium ([Ca](i)) of dispersed bovine parathyroid cells, using the fluorescent dye indo-1. The addition of 10-8 M 1,25-(OH)2D3 caused an increase in [Ca](i) by 23.4 ± 2.7% over a 10 minute period. There was a significant increase in [Ca](i) within two minutes of the addition of 1,25-(OH)2D3. 1,25-(OH)2D3 increases [Ca](i) in a dose-dependent manner and this occurred with as little as 10-10 M. Neither 10-7 M 25-(OH)D3 nor 10-7 M 24, 25-(OH)2D3 caused a significant increase in [Ca](i). Chelation of extracellular calcium with EGTA blocked the 1,25-(OH)2D3-induced increase in [Ca](i), suggesting that the increase was mainly from extracellular calcium. Neither 10-5 M verapamil nor 10-4 M diltiazem blocked the 1,25-(OH)2D3-induced increase in [Ca](i). The present data suggest that 1,25-(OH)2D3 might modify membrane permeability to calcium independent of voltage-dependent calcium channels sensitive to verapamil or diltiazem. The rapid effect of 1,25-(OH)2D3 raises the possibility that its mechanism is independent of genome activation, perhaps attributable to direct interaction with components of the parathyroid cell plasma membrane.
AB - We examined the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on cytosolic calcium ([Ca](i)) of dispersed bovine parathyroid cells, using the fluorescent dye indo-1. The addition of 10-8 M 1,25-(OH)2D3 caused an increase in [Ca](i) by 23.4 ± 2.7% over a 10 minute period. There was a significant increase in [Ca](i) within two minutes of the addition of 1,25-(OH)2D3. 1,25-(OH)2D3 increases [Ca](i) in a dose-dependent manner and this occurred with as little as 10-10 M. Neither 10-7 M 25-(OH)D3 nor 10-7 M 24, 25-(OH)2D3 caused a significant increase in [Ca](i). Chelation of extracellular calcium with EGTA blocked the 1,25-(OH)2D3-induced increase in [Ca](i), suggesting that the increase was mainly from extracellular calcium. Neither 10-5 M verapamil nor 10-4 M diltiazem blocked the 1,25-(OH)2D3-induced increase in [Ca](i). The present data suggest that 1,25-(OH)2D3 might modify membrane permeability to calcium independent of voltage-dependent calcium channels sensitive to verapamil or diltiazem. The rapid effect of 1,25-(OH)2D3 raises the possibility that its mechanism is independent of genome activation, perhaps attributable to direct interaction with components of the parathyroid cell plasma membrane.
UR - http://www.scopus.com/inward/record.url?scp=0023876703&partnerID=8YFLogxK
U2 - 10.1038/ki.1988.76
DO - 10.1038/ki.1988.76
M3 - Article
C2 - 3386137
AN - SCOPUS:0023876703
SN - 0085-2538
VL - 33
SP - 850
EP - 854
JO - Kidney International
JF - Kidney International
IS - 4
ER -