Endothelin-induced changes in intracellular calcium concentration in rat vascular smooth muscle cells: Effects of extracellular calcium and atrial natriuretic factor

1992 ◽  
Vol 7 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Motoyuki Nakamura ◽  
Tessa J. Abell ◽  
A. Mark Richards ◽  
Hamid Ikram ◽  
Eric A. Espiner ◽  
...  
1994 ◽  
Vol 21 (4) ◽  
pp. 521-526 ◽  
Author(s):  
Anna Castro ◽  
Josefa Ros ◽  
Wladimiro Jiménez ◽  
Joan Clària ◽  
Joan Llibre ◽  
...  

2012 ◽  
Vol 22 (2) ◽  
pp. 436-442 ◽  
Author(s):  
Aurylene C. Oliveira ◽  
José G. Sena-Filho ◽  
Leônidas G. Mendes-Júnior ◽  
Raline M. Anjos ◽  
Thaís P. Ribeiro ◽  
...  

1989 ◽  
Vol 256 (2) ◽  
pp. C234-C240 ◽  
Author(s):  
M. S. Siskind ◽  
C. E. McCoy ◽  
A. Chobanian ◽  
J. H. Schwartz

Intracellular calcium (Cai2+) and intracellular pH (pHi) are important regulators of a variety of intracellular processes. Cai2+ is a regulator of muscle contraction, but the role of pHi is unclear. The purpose of this study was to determine the effect of alterations of pHi on Cai2+. A7r5 vascular smooth muscle cells (VSMC) were grown to confluence on glass cover slips. Cai2+ was determined with the fluorescent probe fura-2 and pHi with 2,7-bis-carboxyethyl-5(6)-carboxy-fluorescein (BCECF). Alkalinization of the VSMC by exposure to 20 mM NH4Cl (delta pHi 0.41 +/- 0.07) resulted in a rise in Cai2+ from 99 +/- 8 to 146 +/- 13 nM (n = 5) in the presence of extracellular Ca2+ (Cao2+). In the absence of Cao2+, NH4Cl-induced alkalinization also resulted in a Cai2+ rise (delta Cai2+ = 26 +/- 4 nM, n = 5). Similar changes in Cai2+ were observed when cells were alkalinized by exposure to nigericin in a KCl buffer (pH 7.7). Neither 100 microM verapamil or 100 microM 8,8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate HCl (TMB-8) altered the alkaline-induced changes. After cellular Ca2+ stores were partially depleted by exposure to AVP in a Ca2+-free solution, subsequent cell alkalinization induced no changes in Cai2+. These results demonstrate that alkalinization of VSMCs leads to a rise in cytosolic Ca2+ via release of intracellular Ca2+ stores. The intracellular Ca2+ storage sites appear to be the same as those sites sensitive to AVP. Thus pHi may regulate Cai2+ and thereby play a role in the regulation of vascular smooth muscle tone.


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