Stimulated release of arachidonic acid from rat liver cells by celecoxib and indomethacin

2001 ◽  
Vol 65 (1) ◽  
pp. 31-35 ◽  
Author(s):  
L. Levine
Keyword(s):  
Arachidonic Acid ◽  
Rat Liver ◽  
Liver Cells ◽  
Rat Liver Cells

scholarly journals Arachidonic acid inhibits the store-operated Ca2+ current in rat liver cells

2005 ◽  
Vol 385 (2) ◽  
pp. 551-556 ◽  
Author(s):  
Grigori Y. RYCHKOV ◽  
Tom LITJENS ◽  
Michael L. ROBERTS ◽  
Greg J. BARRITT
Keyword(s):  
Arachidonic Acid ◽  
Rat Liver ◽  
Membrane Conductance ◽  
Rat Hepatocytes ◽  
Cell Types ◽  
Receptor Activation ◽  
Liver Cells ◽  
H4iie Cells ◽  
Rat Liver Cells ◽  
Ca2 Channels

Vasopressin and other phospholipase-C-coupled hormones induce oscillations (waves) of [Ca2+]cyt (cytoplasmic Ca2+ concentration) in liver cells. Maintenance of these oscillations requires replenishment of Ca2+ in intracellular stores through Ca2+ inflow across the plasma membrane. While this may be achieved by SOCs (store-operated Ca2+ channels), some studies in other cell types indicate that it is dependent on AA (arachidonic acid)-activated Ca2+ channels. We studied the effects of AA on membrane conductance of rat liver cells using whole-cell patch clamping. We found no evidence that concentrations of AA in the physiological range could activate Ca2+-permeable channels in either H4IIE liver cells or rat hepatocytes. However, AA (1–10 μM) did inhibit (IC50=2.4±0.1 μM) Ca2+ inflow through SOCs (ISOC) initiated by intracellular application of Ins(1,4,5)P3 in H4IIE cells. Pre-incubation with AA did not inhibit ISOC development, but decreased maximal amplitude of the current. Iso-tetrandrine, widely used to inhibit receptor-activation of phospholipase A2, and therefore AA release, inhibited ISOC directly in H4IIE cells. It is concluded that (i) in rat liver cells, AA does not activate an AA-regulated Ca2+-permeable channel, but does inhibit SOCs, and (ii) iso-tetrandrine and tetrandrine are effective blockers of CRAC (Ca2+-release-activated Ca2+) channel-like SOCs. These results indicate that AA-activated Ca2+-permeable channels do not contribute to hormone-induced increases or oscillations in [Ca2+]cyt in liver cells. However, AA may be a physiological modulator of Ca2+ inflow in these cells.

Sign in / Sign up

Export Citation Format

Share Document