Inhibition of low-density cell formation by calcium.

(A) To determine the effect of calcium on light cell formation, 7 experiments were performed. During oxy/deoxy cycling, calcium decreased low-density cell formation compared with the concurrent, calcium-free control by 38%. Calcium did not have an effect on the oxy-incubated cells (P > .65). (B) To determine the effect of Ca⁺⁺ plus 1 μM charybdotoxin, a K_Ca inhibitor, 6 experiments were performed. During oxy/deoxy cycling, ChTX increased low-density cell formation by 46% compared with its concurrent Ca⁺⁺ control, but had no effect on oxy incubation (P > .08).