Figure 1.

Counter-regulatory response to hypoglycemia in rat carotid body (CB) slices and isolated glomus cells. A representative secretory response (A) and average secretion rate (B) induced by glucopenia in glomus cells from CB slices (n = 3). (C) Abolition of the secretory response to hypoglycemia by 100 μM Cd²⁺. A representative depolarizing receptor potential (D) and average membrane potential (E) induced by 0 glucose in CB glomus cells (n = 25). (F) Reversible increase in cytosolic Ca²⁺ concentration in a Fura-2-loaded glomus cell in response to 0 glucose. (G) Abolition of 0 glucose-induced increase in current (Icontrol-I0glu) by replacement of extracellular Na⁺ with N-methyl-D-glucamine (0 Na⁺) in voltage-clamped glomus cells (n = 3). (H) Inhibition of 0 glucose-induced depolarization (Vcontrol-V0glu) by replacement of extracellular Na⁺ with N-methyl-D-glucamine (0 Na⁺) in current-clamped glomus cells (n = 3). To compensate for the hyperpolarization induced by 0 Na⁺, Vm was changed manually to the previous resting value (arrow) ^*p < 0.05 (Modified from Garcia-Fernandez et al., 2007).