Question

The hormone erythropoietin (EPO) is sometimes used as a performance-enhancing drug by endurance athletes; because of this, it has been banned my most athletic regulatory agencies. It acts to increase the differentiation of new red blood cells (erythrocytes), thus increasing the erythrocyte content of the blood. While it is debated whether EPO is actually effective at enhancing exercise performance, it could hypothetically have an effect by:

A increasing alveolar ventilation rate.

B increasing cardiac output.

C increasing blood oxygen carrying capacity.

D increasing the partial pressure of oxygen (P_{O_2}) dissolved in the blood plasma returning from pulmonary circulation.

Answer 1

Option C is true regarding enhancement of performance

EPO is secreted by the peritubular cells in the kidney in response to hypoxia

So it increases the red blood cells maturation and thus causes increase in the number of red blood cells in the circulation. Increased RBC will cause an increase in the oxygen carrying capacity due to more hemoglobin. This enhanced oxygen carrying capacity will give advantage to the athletes to enhance their performance

EPO usually doesn't have much impact on cardiac output and alveolar ventilation

EPO doesn't increase the amount of oxygen that is carried in the dissolved form in the plasma

Hope this helps.... Thank you!!!