Figure 2. Intracellular calcium () responses of aortic body (AB) and carotid body (CB) type I cells to chemostimuli.

Example Ca²⁺ traces from responsive AB type I cells (A) and CB type I cells (B), to hypoxia (Hox; ∼25 mmHg), isohydric hypercapnia (10% CO₂, pH 7.4), isocapnic acidosis (5% CO₂, pH ∼6.9; H⁺) and acidic hypercapnia (10% CO₂, pH ∼7.1). In C, a complete trace from an AB type I cell within a triplet shows responses to all 4 chemostimuli and the depolarizing stimulus, high (30 mm) K⁺. Isocapnic acidosis (H⁺) elicited the largest responses regardless of stimulus order, but was usually applied last because there was continuous Ca²⁺ activity even after washout.