Abstract
To determine whether the functional Ca2+ channel exist in the vestibular dark cells, an increase in intracellular Ca2+ concentration ([Ca2+]i) due to high K+ application was measured in dark cells isolated from the ampullae of the semicircular canal of the guinea pig using the Ca2+ sensitive dye, Fura-2, and digital imaging microscopy. When 40 mM K+was added to the bath, there was a rapid increase in [Ca2+]i which returned to the original level after washing. Application of the Ca2+ channel blocker, nifedipine (1 μM) blocked the incraese in [Ca2+]i. These results suggest the existence of voltage-dependent Ca2+ channels in the dark cells, which are presumably involved in the regulation of Ca2+ concentration in vestibular endolymph.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
