| pubmed-article:7733912 | pubmed:abstractText | Since the role of intrinsic inactivation of the receptor for inositol 1,4,5-trisphosphate (InsP3) in the phenomenon of quantal release of Ca2+ is still a point of debate, we investigated whether inactivation of the InsP3 receptor can be responsible for quantal release in permeabilized A7r5 cells. A crucial experiment was that a second challenge of the cells with a low dose of InsP3, after washing out the first challenge, was unable to produce a renewed phasic response under conditions where the Ca2+ pumps were blocked. A new phasic response was however obtained with either addition of a higher dose of InsP3 or after allowing the refilling of the Ca2+ stores. We conclude therefore that quantal Ca2+ release in A7r5 cells is not due to InsP3 receptor inactivation. | lld:pubmed |
