title: Mechanism of [Ca2+]i rise induced by angiotensin 1-7 in MDCK renal tubular cells.
abstract: The effect of angiotensin 1-7 (Ang 1-7) on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) in MDCK renal tubular cells was explored. The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca(2+)](i). Ang 1-7 at concentrations of 10-50 µM induced a [Ca(2+)](i) rise in a concentration-dependent manner. The response was reduced partly by removing Ca(2+). Ang 1-7 evoked store operated Ca(2+) entry that was inhibited by La(3+) and aristolochic acid. In the absence of extracellular Ca(2+), incubation with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin prevented Ang 1-7 from releasing more Ca(2+). Inhibition of phospholipase C with U73122 abolished Ang 1-7-induced [Ca(2+)](i) rise. Ang 1-7-induced [Ca(2+)](i) rise was abolished by the angiotensin type 1 receptor antagonist losartan, but was not affected by the angiotensin type 2 receptor antagonist PD 123,319. In sum, in MDCK cells, Ang 1-7 stimulated angiotensin type 1 receptors leading to a [Ca(2+)](i) rise that was composed of phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via phospholipase A2-sensitive store-operated Ca(2+) channels.
authors.affiliation: Department of Internal Medicine, Yuan's General Hospital, Kaohsiung, Taiwan.
authors.forename: Chung-Pin
authors.initials: CP
authors.lastname: Liu
authors.forename: Chiang-Ting
authors.initials: CT
authors.lastname: Chou
authors.forename: Chao-Chuan
authors.initials: CC
authors.lastname: Chi
authors.forename: Ko-Long
authors.initials: KL
authors.lastname: Lin
authors.forename: He-Hsiung
authors.initials: HH
authors.lastname: Cheng
authors.forename: Yi-Chau
authors.initials: YC
authors.lastname: Lu
authors.forename: Jin-Shiung
authors.initials: JS
authors.lastname: Cheng
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Kuo
authors.forename: Wei-Zhe
authors.initials: WZ
authors.lastname: Liang
authors.forename: I-Fei
authors.initials: IF
authors.lastname: Huang
authors.forename: Chung-Ren
authors.initials: CR
authors.lastname: Jan
mesh_terms: D000803:Angiotensin I / Q000494:pharmacology*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D057912:Angiotensin II Type 2 Receptor Blockers / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004963:Estrenes / Q000494:pharmacology; D016257:Fura-2; D007668:Kidney / Q000378:metabolism* / Q000502:physiology; D061985:Madin Darby Canine Kidney Cells; D010446:Peptide Fragments / Q000494:pharmacology*; D054467:Phospholipases A2 / Q000378:metabolism; D011760:Pyrrolidinones / Q000494:pharmacology; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D044139:Receptor, Angiotensin, Type 2 / Q000378:metabolism; D019284:Thapsigargin / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D057912:Angiotensin II Type 2 Receptor Blockers; D004963:Estrenes; D010446:Peptide Fragments; D011760:Pyrrolidinones; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D019284:Thapsigargin; D000803:Angiotensin I; D054467:Phospholipases A2; D010738:Type C Phospholipases; C118790:angiotensin I (1-7); D002118:Calcium; D016257:Fura-2