Yeh JH, Cheng HH, Huang CJ, Chung HM, Chiu HF, Yang YL, Yeh MY, Chen WC, Kao CH, Chou CT, Jan CR. Effect of Anandamide on Cytosolic Ca2+ Levels and Proliferation in Canine Renal Tubular Cells.
Basic Clin Pharmacol Toxicol 2006;
98:416-22. [PMID:
16623868 DOI:
10.1111/j.1742-7843.2006.pto_350.x]
[Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effect of the endogenous cannabinoid anandamide on cytosolic free Ca(2+) concentration ([Ca(2+)](i)) and proliferation is largely unknown. This study examined whether anandamide altered Ca(2+) levels and caused Ca(2+)-dependent cell death in Madin-Darby canine kidney (MDCK) cells. [Ca(2+)](i) and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Anandamide at concentrations above 5 muM increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced by 78% by removing extracellular Ca(2+). The anandamide-induced Ca(2+) influx was insensitive to L-type Ca(2+) channel blockers and the cannabinoid receptor antagonist AM 251, but was inhibited differently by aristolochic acid, WIN 55,212-2 (a cannabinoid receptor agonist), phorbol ester, GF 109203X and forskolin. After pretreatment with thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), anandamide-induced Ca(2+) release was inhibited. Inhibition of phospholipase C with U73122 did not change anandamide-induced Ca(2+) release. At concentrations of 100 muM and 200 muM, anandamide killed 50% and 95% cells, respectively. The cytotoxic effect of 100 muM anandamide was completely reversed by pre-chelating cytosolic Ca(2+) with BAPTA. Collectively, in MDCK cells, anandamide induced [Ca(2+)](i) rises by causing Ca(2+) release from endoplasmic reticulum and Ca(2+) influx from extracellular space. Furthermore, anandamide can cause Ca(2+)-dependent cytotoxicity in a concentration-dependent manner.
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