ATP release from freshly isolated guinea-pig bladder urothelial cells: a quantification and study of the mechanisms involved

作者：McLatchie Linda M^*; Fry Christopher H

来源：BJU International, 2015, 115(6): 987-993.

DOI：10.1111/bju.12954

• bladder
• urothelial cells
• ATP
• calcium
• hemichannel
• vesicular release

ObjectivesTo quantify the amount of ATP released from freshly isolated bladder urothelial cells, study its control by intracellular and extracellular calcium and identify the pathways responsible for its release.
Materials and MethodsUrothelial cells were isolated from male guinea-pig urinary bladders and stimulated to release ATP by imposition of drag forces by repeated pipetting. ATP was measured using a luciferin-luciferase assay and the effects of modifying internal and external calcium concentration and blockers of potential release pathways studied.
ResultsFreshly isolated guinea-pig urothelial cells released ATP at a mean (sem) rate of 1.9(0.1)pmoles/mm(2) cell membrane, corresponding to about 700pmoles/g of tissue, and about half [49(6)%, n = 9) of the available cell ATP. This release was reduced to a mean (sem) of 0.46(0.08)pmoles/mm(2) (160pmoles/g) with 1.8mm external calcium, and was increased about two-fold by increasing intracellular calcium. The release from umbrella cells was not significantly different from a mixed intermediate and basal cell population, suggesting that all three groups of cells release a similar amount of ATP per unit area. ATP release was reduced by approximate to 50% by agents that block pannexin and connexin hemichannels. It is suggested that the remainder may involve vesicular release.
ConclusionsA significant fraction of cellular ATP is released from isolated urothelial cells by imposing drag forces that cause minimal loss of cell viability. This release involves multiple release pathways, including hemichannels and vesicular release.

• 出版日期2015-6