Chloride shift occurs in respond to.

Chloride shift is a process that takes place when CO2 enters blood from the tissues and gets converted into bicarbonate ions by carbonic anhydrase, leading to accumulation of bicarbonate ions in the RBCs. Thus,chloride shift could be defined as the diffusion of Chloride anions (Cl-) from blood plasma into cytoplasm of RBCs as well as diffusion of bicarbonate anions (HCO3-) out of cytoplasm of erythrocytes (RBCs) into the blood plasma. This serves to maintain the electrochemical neutality in RBCs or maintaining the blood pH. These bicarbonate and chloride ions are transported across the red blood cell membrane in opposite directions by the bicarbonate-chloride carrier protein.