We examined the effects of superoxide anion (O2/-) on the intracellular Ca2+ concentration in cultured human nasal epithelial cells. The cells were exposed to O2/- by pretreatment with xanthine (X) and xanthine oxidase (XO); control cells were treated with X alone. When Ca2+-containing Krebs solution was reperfused in the thapsigargin-treated, store- depleted cells, reapplication-induced intracellular Ca2+ concentration elevation was significantly smaller in X/XO-treated cells than in the control cells, suggesting that O2/- impairs Ca2+ release-activated Ca2+ entry (CRAC). Bath application of ATP induced a steep Ca2+ transient in both control and X/XO- treated cells. However, the concentration-response curve of the ATP-induced Ca2+ transient was shifted to a higher concentration in X/XO-treated cells. The impairments of CRAC and ATP-induced Ca2+ transient induced by X/XO were reversed by superoxide dismutase. Furthermore, all these X/XO-induced effects were also observed in cells pretreated with pyrogallol, also an O2/- donor. These results indicate that O2/- impairs at least two mechanisms involved in Ca2+ mobilization in human nasal epithelial cells, i.e., CRAC and ATP-induced Ca2+ release.
|Journal||American Journal of Physiology - Lung Cellular and Molecular Physiology|
|Issue number||6 21-6|
|Publication status||Published - Dec 1 1999|
All Science Journal Classification (ASJC) codes
- Pulmonary and Respiratory Medicine
- Physiology (medical)
- Cell Biology