1. Metabolic effects of CO 2 Alice Skoumalová

2. Overview of oxidative fuel metabolism:

3. Carbon dioxide transport: CO 2 in the blood: 1. as HCO 3 - (ionization of H 2 CO 3 )75-85 % 2. as carbamino groups (CO 2 reacts with amino groups of proteins)10-15 % 3. dissolved CO 2 5-12 % Partial pressures air-inspiration air-expiration arterial blood venous blood pO 2 (kPa) 21 15,3 12 – 13,3 4,6 - 6 pCO 2 (kPa) 0,03 4,4 4,6 – 6 5,3 – 6,6 CO 2 + H 2 O H 2 CO 3 H + + HCO 3 - erythrocytes (carbonate dehydratase)

4. O 2 and CO 2 transport: Bohr effect (the increase in acidity of hemoglobin as it binds O 2, releases H + ) Isohydric carriage of CO 2 (Hb‘s ability to take up H + with no change in pH through Bohr effect) Chloride shift (the exchange of Cl - and HCO 3 - between the plasma and the erythrocyte)

5. Hypercapnia protects against free radical damage during hypoxia-ischemia: Stabilization of the iron-transferrin complex Shift of the oxygen-hemoglobin saturation curve to the right Effects on metabolism (improve aerobic metabolism, reduced lactate production, ATP generation) Direct inhibition of the free radicals Perinatal brain hypoxic-ischemic damage Mechanical ventilation Chronic respiratory failure

6. CO 2 : protective effect or radical damage ?