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Effect of Anandamide on Cytosolic Ca 2+ Levels and Proliferation in Canine Renal Tubular Cells
Author(s) -
Yeh JengHsien,
Cheng HeHsiung,
Huang ChunJen,
Chung HsiaoMin,
Chiu HuiFen,
Yang YuLin,
Yeh MeiYin,
Chen WeiChuan,
Kao ChengHsing,
Chou ChiangTing,
Jan ChungRen
Publication year - 2006
Publication title -
basic and clinical pharmacology and toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.805
H-Index - 90
eISSN - 1742-7843
pISSN - 1742-7835
DOI - 10.1111/j.1742-7843.2006.pto_350.x
Subject(s) - anandamide , cannabinoid receptor , thapsigargin , extracellular , cannabinoid , chemistry , endoplasmic reticulum , bapta , endocannabinoid system , medicine , endocrinology , agonist , biochemistry , biology , receptor
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 μM 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 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 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.