Question

The chloride shift is the movement of CI
A. From plasma to RBC
B. From WBC to plasma
C. Both of the above
D. None of the above

Answer 1

Hint: Chloride shift is also known as the Hamburger Phenomenon or Lineas Phenomenon, which occurs in the cardiovascular system, where there is an exchange of bicarbonate and chloride ions across the membrane of the red blood cell.

Complete answer:
Chloride shift regulates the affinity of hemoglobin to oxygen and this chloride acts as an allosteric effector.
In the body due to metabolism, carbon dioxide is produced as a byproduct, and this carbon dioxide dissolves in the blood plasma and the RBC where it forms the carbonic acid, where it is unstable and at the same time, the enzyme carbonic anhydrase enzyme breaks down this carbonic acid into bicarbonate and hydrogen ions.
As more Carbon dioxide is produced in the cell, more carbonic acid forms and dissociates to the bicarbonate’s ions.
Because of this, there is more increase in the bicarbonate ion concentration in the intracellular, which causes the exchange with chloride ions.
Carbon dioxide is generally impermeable to ions exchange but the bicarbonate exchange takes place by the anion exchange protein Band 3 channels.
So this rise in intracellular bicarbonate leads to the export of the carbon dioxide and intake of chloride ions and this exchange is considered as chloride shift.

Here bicarbonates are expelled out from the RBC to Plasma, while Chloride is intaken from plasma to RBC so the correct option is A.

Note: In the pulmonary capillaries, a reverse of Chloride shift occurs, which is called Halden’s effect, because in the lungs partial pressure of oxygen is more and hydrogen ions concentration is present more in the intracellular level so with the help of band exchanger 3 chloride ions sent out and bicarbonate is taken in.