Figure 5
Role of intracellular Ca2+stores and extracellular Ca2+in ATP-induced response. A: Fmax to 10-3 M ATP in rings from rat trachea (black column, n = 8) left (LEPB) and right (REPB) EPB (hatched columns, n = 8), and left IPB (cross-hatched column, n = 6) after depletion of intracellular Ca2+ stores by application of thapsigargin and caffeine. Horizontal bars are Fmax in control conditions B: Fmax to 10-3 M ATP rings from rat trachea (black column, n = 8) left (LEPB, n = 8) and right (REPB, n = 7) EPB (hatched columns), and left IPB (cross-hatched column, n = 8), and in human IPB (HumIPB, cross-hatched column, n = 5) in the absence of external Ca2+. Horizontal bars are Fmax in control conditions. C: percentage of rat freshly isolated tracheal myocytes responding to 10-3 M ATP, and amplitude of the [Ca2+]i peak, in the presence (black columns, n = 61) and in the absence (grey columns, n = 30) of external Ca2+. Error bars are SEM. *P < 0.05.