Effect of Anandamide on Cytosolic Ca2+ Levels and Proliferation in Canine Renal Tubular Cells

: The effect of the endogenous cannabinoid anandamide on cytosolic free Ca2+ concentration ([Ca2+]i) and proliferation is largely unknown. This study examined whether anandamide altered Ca2+ levels and caused Ca2+‐dependent cell death in Madin‐Darby canine kidney (MDCK) cells. [Ca2+]i and cell death...

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Published in:Basic & clinical pharmacology & toxicology 2006-04, Vol.98 (4), p.416-422
Main Authors: Yeh, Jeng‐Hsien, Cheng, He‐Hsiung, Huang, Chun‐Jen, Chung, Hsiao‐Min, Chiu, Hui‐Fen, Yang, Yu‐Lin, Yeh, Mei‐Yin, Chen, Wei‐Chuan, Kao, Cheng‐Hsing, Chou, Chiang‐Ting, Jan, Chung‐Ren
Format: Article
Language:English
Subjects:
Biological and medical sciences
Medical sciences
Pharmacology. Drug treatments
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Summary:: The effect of the endogenous cannabinoid anandamide on cytosolic free Ca2+ concentration ([Ca2+]i) and proliferation is largely unknown. This study examined whether anandamide altered Ca2+ levels and caused Ca2+‐dependent cell death in Madin‐Darby canine kidney (MDCK) cells. [Ca2+]i and cell death were measured using the fluorescent dyes fura‐2 and WST‐1 respectively. Anandamide at concentrations above 5 μM increased [Ca2+]i in a concentration‐dependent manner. The Ca2+ signal was reduced by 78% by removing extracellular Ca2+. The anandamide‐induced Ca2+ influx was insensitive to L‐type Ca2+ 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 Ca2+ pump inhibitor), anandamide‐induced Ca2+ release was inhibited. Inhibition of phospholipase C with U73122 did not change anandamide‐induced Ca2+ release. At concentrations of 100 μM and 200 μM, anandamide killed 50% and 95% cells, respectively. The cytotoxic effect of 100 μM anandamide was completely reversed by pre‐chelating cytosolic Ca2+ with BAPTA. Collectively, in MDCK cells, anandamide induced [Ca2+]i rises by causing Ca2+ release from endoplasmic reticulum and Ca2+ influx from extracellular space. Furthermore, anandamide can cause Ca2+‐dependent cytotoxicity in a concentration‐dependent manner.
ISSN:1742-7835
1742-7843
DOI:10.1111/j.1742-7843.2006.pto_350.x