Effect of vanadate on ATP-induced increase in intracellular calcium ion levels in human umbilical vein endothelial cells.
We investigated the effect of ammonium vanadate (vanadate) on ATP-induced increases in intracellular calcium ion level ([Ca(2+)](i)) of human umbilical vein endothelial cells (HUVEC) by fluorescence confocal microscopic imaging using the Ca(2+)-sensitive probe Calcium Green 1/AM. The ATP analogue 2-methylthio-ATP (2meS-ATP), at 10 microM, significantly increased the [Ca(2+)](i) of HUVEC, and this was abolished by 1 microM thapsigargin (a calcium pump inhibitor), whereas extracellular free calcium had no effect. Vanadate at 10 microM also significantly increased the [Ca(2+)](i) of HUVEC, which was abolished by 1 microM thapsigargin. However, vanadate at 1 microM did not exert such a significant effect. We thus examined the influence of < or =1 microM vanadate for 24 h on 2meS-ATP-induced increase in [Ca(2+)](i). Vanadate significantly reduced the action of 2meS-ATP at 1 microM but not at 0.1 microM. Endogenously released ATP is known to induce various actions on endothelial cells. The present results suggest that vanadate exerts a regulatory influence on the function of vascular endothelial cells.
Department of Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Hyogo 663-8179, Japan.
Namie
N
Nejime
Yukari
Y
Tada
Satomi
S
Kagota
Yoko
Y
Kubota
Ikuo
I
Shibuichi
Yuki
Y
Shinoda
Tomohiro
T
Yamamoto
Yasuo
Y
Watanabe
Kazumasa
K
Shinozuka
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D019284:Thapsigargin / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology; D014471:Umbilical Veins; D014638:Vanadates / Q000494:pharmacology*
D013873:Thionucleotides; D014638:Vanadates; D019284:Thapsigargin; D000255:Adenosine Triphosphate; D002118:Calcium; C008501:2-methylthio-ATP