IL-4 inhibits calcium transients in bovine trachealis cells by a ryanodine receptor-dependent mechanism

SPECIFIC AIMS1. Interleukin (IL) -4 effects on SR calcium mobilizationBrief treatment of bovine airway smooth muscle cells with the inflammatory cytokine IL-4, but not IL-13, inhibits the magnitude of calcium transients stimulated by carbachol or caffeine, suggesting that IL-4 could have important effects on the calcium signaling that regulates contraction or other cellular functions. To account for this rapid inhibitory effect of IL-4, the first aim of this study was to determine whether IL-4 blocks calcium release from the sarcoplasmic reticulum (SR) or, instead, decreases the amount of calcium in the SR available for release.2. Role of ryanodine receptor (RyR) calcium release channelsThe second aim of the study was to determine whether the inhibitory effect of IL-4 on calcium transients depended on cyclic ADP-ribose (cADPR) and RyR calcium release channels.PRINCIPAL FINDINGS1. Treatment with IL-4, but not IL-13, inhibits the magnitude of ionomycin-stimulated calcium transientsBovine trachealis cells we...