Effects of endothelin-1 on [Ca2+]i and pHi in trabecular meshwork cells.
We examined the effects of endothelin-1 (ET-1) on [Ca2+]i and intracellular pH in cultured bovine trabecular meshwork cells and compared the effects of ET-1 with those of angiotensin II (another phospholipase C activating peptide). [Ca2+]i was measured with the Ca2+ fluorescent dye indo-1. Intracellular pH was measured using the pH sensitive fluorescent dye BCECF. Exposure to ET-1 (10 nM) produced a transient increase in [Ca2+]i (from 77.3 +/- 17.3 nM to 503.0 +/- 64.8 nM, p < 0.05, n = 12). Intracellular pH was also increased during exposure to 10 nM ET-1 (+0.081 unit, p < 0.05, n = 6). In the presence of 10 microM EIPA, ET-1 (10 nM) did not change intracellular pH. Angiotensin II did not significantly change [Ca2+]i or intracellular pH. These results suggest that ET-1 may be involved in the regulation of aqueous humor dynamics by changing [Ca2+]i and intracellular pH in trabecular meshwork cells.
Kohmoto
H
H
Department of Ophthalmology, Faculty of Medicine, University of Tokyo, Japan.
Matsumoto
S
S
Serizawa
T
T
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D016232:Endothelins / Q000494:pharmacology*; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D007211:Indoles; D014129:Trabecular Meshwork / Q000166:cytology / Q000378:metabolism*
D016232:Endothelins; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007211:Indoles; D000804:Angiotensin II; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; C048960:indo-1; D002118:Calcium