How could a hematocrit test be used to determine if an athlete was abusing erythropoietin (EPO)?

• A. By measuring the percentage of red blood cells in the blood, a significantly elevated hematocrit could indicate EPO abuse.
• B. By assessing the oxygen saturation of hemoglobin in the blood.
• C. By detecting the presence of EPO molecules directly in the bloodstream.
• D. By measuring the concentration of white blood cells, which increases with EPO use.

Answer: (A)

Verified step by step guidance

1. Understand the purpose of a hematocrit test: A hematocrit test measures the percentage of red blood cells (RBCs) in the blood. This is important because erythropoietin (EPO) stimulates the production of RBCs, which can lead to elevated hematocrit levels.
2. Recognize the connection between EPO and hematocrit levels: EPO is a hormone that promotes the production of red blood cells in the bone marrow. Athletes abusing EPO may have abnormally high hematocrit levels due to increased RBC production.
3. Eliminate irrelevant options: Assess the provided answer choices. Measuring oxygen saturation of hemoglobin, detecting EPO molecules directly, or measuring white blood cell concentration are not directly related to hematocrit testing for EPO abuse.
4. Focus on the correct method: Elevated hematocrit levels are a key indicator of EPO abuse. A significantly high percentage of RBCs in the blood suggests that the athlete may be using EPO to enhance oxygen delivery and performance.
5. Conclude the reasoning: The hematocrit test is used to measure the percentage of RBCs in the blood, and a significantly elevated hematocrit level could indicate EPO abuse. This is the most relevant and scientifically accurate method among the options provided.