TY - JOUR
T1 - Endothelin receptor A is expressed and mediates the [Ca2+](i) mobilization of cells in human ciliary smooth muscle, ciliary nonpigmented epithelium, and trabecular meshwork
AU - Tao, Wenhong
AU - Prasanna, Ganesh
AU - Dimitrijevich, Slobodan
AU - Yorio, Thomas
N1 - Funding Information:
The authors thank Dr. Iok-Hou Pang for human ciliary smooth muscle cells. This work was supported in part by a grant from the Texas Higher Education Coordinating Board (Grant number: 09768-008/018).
PY - 1998
Y1 - 1998
N2 - Purpose. To identify which endothelin receptor subtype is expressed and is functional in the human ciliary body and trabecular meshwork, tissues that regulate aqueous humor dynamics. Methods. Immunocytochemistry was used to characterize the primary culture cells of normal human ocular cells. Endothelin receptor gene expression was probed with reverse transcription of polymerase chain reaction (RT-PCR). Intracellular calcium ([Ca2+](i)) mobilization was measured with video image microscopy using Fura-2AM as a fluorescent probe. Results. Identities of primary cultures, human ciliary smooth muscle (HCSM), ciliary nonpigmented epithelial (HCE), and trabecular meshwork (HTM) cells were confirmed by immunocytochemistry, using cell-specific markers and observing typical cell morphologies. The presence of endothelin receptor A (ET(A)) was detected with RT-PCR in all three types of cells. The mRNA phenotype was verified with restriction enzyme BamHI digestion. No ET(B) receptor subtype expression was detected with RT-PCR under the cell culture conditions used. The [Ca2+](i) of HCSM cells was increased from 57 ± 7 nM to 328 ± 108 nM (n = 23; mean ± SE; P < 0.05) by 1 nM endothelin-1 (ET-1). In HCE cells, [Ca2+](i) increased from 40 ± 3 nM to 90 ± 10 nM (n = 55) (P < 0.001) with the same concentration of ET-1. Similarly, ET-1 (1 nM) increased the [Ca2+](i) from 51 ± 6 nM to 185 ± 47 nM (n = 19) (P < 0.001) in the HTM cells. The agonist for ET(B), S6c, had no effect on [Ca2+](i) transients in all three cell types. No ET(B) receptor expression was detected in these cell types under the experimental and culture conditions. Conclusion. ET(A) receptor is expressed and is possibly responsible for mediating the signal for [Ca2+](i) mobilization by ET-1 in human ciliary smooth muscle, ciliary nonpigmented epithelial cells, and trabecular meshwork cells.
AB - Purpose. To identify which endothelin receptor subtype is expressed and is functional in the human ciliary body and trabecular meshwork, tissues that regulate aqueous humor dynamics. Methods. Immunocytochemistry was used to characterize the primary culture cells of normal human ocular cells. Endothelin receptor gene expression was probed with reverse transcription of polymerase chain reaction (RT-PCR). Intracellular calcium ([Ca2+](i)) mobilization was measured with video image microscopy using Fura-2AM as a fluorescent probe. Results. Identities of primary cultures, human ciliary smooth muscle (HCSM), ciliary nonpigmented epithelial (HCE), and trabecular meshwork (HTM) cells were confirmed by immunocytochemistry, using cell-specific markers and observing typical cell morphologies. The presence of endothelin receptor A (ET(A)) was detected with RT-PCR in all three types of cells. The mRNA phenotype was verified with restriction enzyme BamHI digestion. No ET(B) receptor subtype expression was detected with RT-PCR under the cell culture conditions used. The [Ca2+](i) of HCSM cells was increased from 57 ± 7 nM to 328 ± 108 nM (n = 23; mean ± SE; P < 0.05) by 1 nM endothelin-1 (ET-1). In HCE cells, [Ca2+](i) increased from 40 ± 3 nM to 90 ± 10 nM (n = 55) (P < 0.001) with the same concentration of ET-1. Similarly, ET-1 (1 nM) increased the [Ca2+](i) from 51 ± 6 nM to 185 ± 47 nM (n = 19) (P < 0.001) in the HTM cells. The agonist for ET(B), S6c, had no effect on [Ca2+](i) transients in all three cell types. No ET(B) receptor expression was detected in these cell types under the experimental and culture conditions. Conclusion. ET(A) receptor is expressed and is possibly responsible for mediating the signal for [Ca2+](i) mobilization by ET-1 in human ciliary smooth muscle, ciliary nonpigmented epithelial cells, and trabecular meshwork cells.
KW - Calcium
KW - Ciliary epithelial cell
KW - Ciliary smooth muscle
KW - Endothelin receptor
KW - Human
KW - Trabecular meshwork
UR - http://www.scopus.com/inward/record.url?scp=0031974504&partnerID=8YFLogxK
U2 - 10.1076/ceyr.17.1.31.5256
DO - 10.1076/ceyr.17.1.31.5256
M3 - Article
C2 - 9472468
AN - SCOPUS:0031974504
SN - 0271-3683
VL - 17
SP - 31
EP - 38
JO - Current Eye Research
JF - Current Eye Research
IS - 1
ER -