. Author manuscript; available in PMC: 2012 Mar 1.

Published in final edited form as: Anesth Analg. 2011 Jan 13;112(3):568–573. doi: 10.1213/ANE.0b013e3182080599

Table 2.

Maximum N-methyl-D-aspartate (NMDA) receptor effect (E_max), median effective concentration (EC₅₀) and Hill coefficient (n_H) estimates for NMDA agonist concentration-responses in the presence (9 mmHg) and absence (0 mmHg) of CO₂. Statistically significant differences between CO₂ treatment parameters for the same agonist (glutamate or glycine) are shaded and boldfaced. A decrease only in the glutamate concentration-response E_max value in the presence of CO₂ is consistent with noncompetitive inhibition. A decrease in the glycine concentration-response E_max with an increase in EC₅₀ in the presence of CO₂ is consistent with mixed inhibition.

Agonist	CO₂ (23°C)	E_max (%)	EC₅₀ (μM)	n_H
Glutamate	0 mmHg	100 ± 1	4.12 ± 0.32	1.30 ± 0.09
Glutamate	9 mmHg	51 ± 2	4.56 ± 0.90	1.20 ± 0.20
Glycine	0 mmHg	100 ± 1	0.71 ± 0.03	1.44 ± 0.07
Glycine	9 mmHg	51 ± 2	1.68 ± 0.09	2.90 ± 0.48