PMID: 8951680Jan 1, 1996Paper

Endothelin-1 mediated Ca2+ influx does not occur through L-type voltage-dependent Ca2+ channels in cultured bovine trabecular meshwork cells

Journal of Ocular Pharmacology and Therapeutics : the Official Journal of the Association for Ocular Pharmacology and Therapeutics
M KageyamaE Shirasawa

Abstract

We evaluated whether endothelin-1-induced changes in cytosolic Ca2+ concentration ([Ca2+]i) involve Ca2+ influx through L-type membrane voltage-dependent Ca2+ channels in cultured bovine trabecular meshwork (TM) cells. The cells were loaded with the fluorescent Ca2+ indicator fura-2 and cell-associated fluorescence was measured with a digital video-imaging analyzer. Application of carbachol (10(-3) M) and norepinephrine (10(-5) M) increased [Ca2+]i only transiently. Endothelin-1 (10(-9) M to 10(-7) M) also increased [Ca2+]i in a concentration-dependent manner, and its effects were larger than those of carbachol and norepinephrine. Unlike carbachol or norepinephrine, endothelin-1 evoked a peak transient effect followed by a sustained elevated level of [Ca2+]i. The only level of the sustained elevated component was dependent on extracellular Ca2+. However, pretreatment with diltiazem (10(-5) M and 10(-4) M), an L-type Ca2+ channel blocker, did not affect either component of the endothelin-1-induced increase in [Ca2+]i. These results suggest that in cultured bovine TM cells endothelin-1 receptors are coupled to Ca2+ signaling mechanisms. However, the extracellular Ca(2+)-dependent increase in [Ca2+]i may not involve Ca2+ influx th...Continue Reading

References

Jul 1, 1991·Experimental Eye Research·A Lepple-WienhuesM Wiederholt
Aug 1, 1991·Circulation Research·C Chen, P K Wagoner
Jan 16, 1989·Biochemical and Biophysical Research Communications·P A MarsdenT A Brock
May 1, 1989·Proceedings of the National Academy of Sciences of the United States of America·K GotoT Masaki

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Citations

Jul 26, 2002·Journal of Glaucoma·Thomas YorioGanesh Prasanna

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