High K+ elevates cytosolic free Ca concentration due to mobilization from internal storage sites in rat parotid cells.
1. Effects of high K+ on cytosolic free Ca concentration ([Ca2+]i) in rat parotid cells were studied using quin2. 2. High K+ elevated [Ca2+]i in a dose-dependent manner in normal and Ca-free media. The elevation of [Ca2+]i induced by high K+ was less in the latter medium. 3. High K+ depolarized the membrane in a dose-dependent manner in normal and Ca-free media. 4. Although monensin increased [Ca2+]i, high K+ did not affect 22Na uptake into cells. 5. After treatment with oligomycin, high K+ but not carbachol raised [Ca2+]i. 6. We suggest that high K+ increases [Ca2+]i due to mobilizing Ca2+ from the intracellular storage site which does not need energy.
D000681:Amylases / Q000378:metabolism; D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D066298:In Vitro Techniques; D007473:Ion Channels / Q000378:metabolism; D010306:Parotid Gland / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D007473:Ion Channels; D000681:Amylases; D011188:Potassium; D002118:Calcium