TY - JOUR
T1 - Expression of extracellular calcium-sensing receptor by human lens epithelial cells
AU - Chattopadhyay, Naibedya
AU - Ye, Chianping
AU - Singh, Dhirendra P.
AU - Kifor, Olga
AU - Vassilev, Peter M.
AU - Shinohara, Toshimiki
AU - Chylack, Leo T.
AU - Brown, Edward M.
N1 - Funding Information:
The authors gratefully acknowledge generous grant support from the following sources: The USPHS [grants DK41415 (to E.M.B. and P.M.V.), DK48330 (to E.M.B.), and DK46422 (to E.M.B.)], the St. Giles Foundation (to E.M.B. and P.M.V.), NPS Pharmaceuticals, Inc. (to E.M.B.), and the Stanley Foundation (to P.M.V. and E.M.B.)
PY - 1997/4/28
Y1 - 1997/4/28
N2 - The extracellular calcium-sensing receptor (CaR) confers the capacity to sense small changes in the extracellular Ca2+ concentration (Ca02+) not only upon cells involved in maintaining systemic Ca2+ homeostasis but also upon those not directly involved in this process. Since high Ca02+ is known to affect various physiological processes in lens epithelium both in health and in disease states (e.g., the formation of cataracts in hypocalcemic states), we investigated the expression and function of the CaR in these cells. By RT-PCR and immunocytochemistry the CaR is expressed in human lens epithelial cells in culture. In addition, the open state probability of a Ca2+-activated potassium (K+) channel with a conductance of 82 +/- 3 pS is significantly increased by elevating Ca02+ to 3.0 mM or by application of 100 μM neomycin, both effective CaR agonists. Therefore, our data suggest that human lens epithelial cells express the CaR, which may be functionally linked to Ca2+-activated K+ channels and, perhaps, to other ion channels involved in ionic homeostasis in the lens.
AB - The extracellular calcium-sensing receptor (CaR) confers the capacity to sense small changes in the extracellular Ca2+ concentration (Ca02+) not only upon cells involved in maintaining systemic Ca2+ homeostasis but also upon those not directly involved in this process. Since high Ca02+ is known to affect various physiological processes in lens epithelium both in health and in disease states (e.g., the formation of cataracts in hypocalcemic states), we investigated the expression and function of the CaR in these cells. By RT-PCR and immunocytochemistry the CaR is expressed in human lens epithelial cells in culture. In addition, the open state probability of a Ca2+-activated potassium (K+) channel with a conductance of 82 +/- 3 pS is significantly increased by elevating Ca02+ to 3.0 mM or by application of 100 μM neomycin, both effective CaR agonists. Therefore, our data suggest that human lens epithelial cells express the CaR, which may be functionally linked to Ca2+-activated K+ channels and, perhaps, to other ion channels involved in ionic homeostasis in the lens.
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U2 - 10.1006/bbrc.1997.6553
DO - 10.1006/bbrc.1997.6553
M3 - Article
C2 - 9168937
AN - SCOPUS:0031589198
VL - 233
SP - 801
EP - 805
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 3
ER -