TableĀ 2.

Estimated binding characteristics of CO2 to Cx26 from four different species. Both the EC50, a measure of binding affinity, and H, a measure of cooperativity, vary across the species. The differences in affinity reflect the physiological needs of the chicken to tolerate hypocapnia and the mole rat to tolerate hypercapnia. The reduced cooperativity of CO2-binding in chicken, rat and mole rat suggests that these species remain sensitive to variations of CO2 over a wider range of partial pressures than humans.

chickenhumanratmole rat
EC50 (mmHg)34444477