Real-time measurement of cytosolic free calcium concentration in DEM-treated HL-60 cells during static magnetic field exposure and activation by ATP

2009 ◽  
Vol 30 (3) ◽  
pp. 213-221 ◽  
Author(s):  
Camilla Rozanski ◽  
Michelle Belton ◽  
Frank S. Prato ◽  
Jeffrey J.L. Carson
Keyword(s):  
Magnetic Field ◽  
Real Time ◽  
Calcium Concentration ◽  
Time Measurement ◽  
Free Calcium ◽  
Cytosolic Free Calcium ◽  
Field Exposure ◽  
Real Time Measurement ◽  
Free Calcium Concentration ◽  
Cytosolic Free Calcium Concentration

Angiotensin II causes sustained elevations in cytosolic calcium in glomerulosa cells

1988 ◽  
Vol 255 (3) ◽  
pp. E338-E346 ◽  
Author(s):  
R. E. Kramer
Keyword(s):  
Angiotensin Ii ◽  
Calcium Concentration ◽  
Cytosolic Calcium ◽  
Calcium Signal ◽  
Free Calcium ◽  
Cytosolic Free Calcium ◽  
Cytosolic Calcium Concentration ◽  
Free Calcium Concentration ◽  
Cytosolic Free Calcium Concentration ◽  
Glomerulosa Cells

Studies were conducted to examine the effects of angiotensin II on cytosolic free calcium concentration in bovine adrenal glomerulosa cells maintained in primary culture. The calcium indicator, fura-2, and discontinuous dual-wavelength fluorescence spectroscopy were used to measure cytosolic free calcium in superfused adherent cell monolayers. Basal cytosolic free calcium concentration was 63.7 +/- 3.3 nM. The threshold concentration for angiotensin II-stimulated increases in cytosolic calcium was 10(-14)-10(-13) M, and maximal elevation of cytosolic calcium was produced by 10(-9) M angiotensin II. Angiotensin II (10(-13) M) produced a gradual increase in cytosolic calcium concentration that plateaued after 3-5 min of superfusion at a level approximately 1.2 times that of control cells. The calcium signal invoked by a maximal concentration (10(-9) M) of angiotensin II, in contrast, was characterized by an immediate, intense (approximately 8-fold) increase in cytosolic calcium concentration that decayed within 5 min to a lower, but sustained, level 2.5-3 times that of control cells. The calcium signals invoked by intermediate concentrations (10(-12)-10(-10) M) of angiotensin II exhibited dose-dependent increases in magnitude and a gradual transition in nature between those invoked by threshold and maximal concentrations of the peptide. The effect of angiotensin II to increase cytosolic calcium concentration was accompanied by an increase in aldosterone output. The increase in steroidogenesis was most closely correlated with the magnitude of the initial calcium signal. At high concentrations (10(-10) and 10(-9) M) of angiotensin II, there was a clear dissociation between aldosterone output and the magnitude of the sustained calcium signal.(ABSTRACT TRUNCATED AT 250 WORDS)

Vasopressin increases cytosolic free calcium in LLC-PK1 cells through a V1-receptor

1987 ◽  
Vol 253 (2) ◽  
pp. F328-F332 ◽  
Author(s):  
M. A. Burnatowska-Hledin ◽  
W. S. Spielman
Keyword(s):  
Parathyroid Hormone ◽  
Arginine Vasopressin ◽  
Calcium Concentration ◽  
Mdck Cells ◽  
Free Calcium ◽  
Base Line ◽  
Cytosolic Free Calcium ◽  
Free Calcium Concentration ◽  
Cytosolic Free Calcium Concentration ◽  
Dose Dependent

We examined the effects of arginine vasopressin (AVP), parathyroid hormone (PTH), and bradykinin (BK) on the cytosolic free calcium concentration ([Ca]i) in cultured LLC-PK1 and MDCK kidney cell lines by use of the fluorescent Ca chelator fura-2. In LLC-PK1 cells, the addition of AVP but not [1-desamino-8-D-arginine]vasopressin (dDAVP, V2 agonist), PTH, or BK (10(-6) M) caused a significant increase in [Ca]i. The AVP-induced increase in [Ca]i from 61 +/- 6 to 225 +/- 44 nM (n = 7, P less than 0.01) was rapid and transient, returning to base line in 2 to 3 min. The effect of AVP was dose dependent and was present at 1 (61% increase) but not 5 min after extracellular Ca was removed. The effect of 10(-6) M AVP could be blocked with the pressor (V1) antagonist, d(CH2)5Tyr(Me)AVP, but not dDAVP. In MDCK cells, BK, but not AVP and PTH, increased [Ca]i from 146 +/- 11 to 281 +/- 31 nM (n = 9, P less than 0.001). The removal of extracellular Ca (5 min), reduced but did not abolish this effect. These results indicate that [Ca]i mobilized by activation of V1-receptors may mediate AVP-regulated function in some transporting epithelia.

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