Capillary permeability and maximal blood flow in skeletal muscle in athletes and non-athletes measured by local clearances of ¹³³Xe and ¹³¹I-

Abstract

The effect of heavy endurance training on capillary diffusion capacity (CDC) and maximal blood flow (MBF) in skeletal muscle was studied in eleven highly-trained athletes and ten sedentary adult volunteers. MBF was estimated from ¹³³Xe clearance and CDC₁ from ¹³³Xe and ¹³¹I- clearances in the anterior tibial muscle after ischaemic exercise. The athletes had a significantly greater MBF, ¹³¹I- clearance and CDC¹ than the control subjects (P< 0.001). The average increment of MBF was 37% and that of CDC¹ 48%. Increase in CDC is considered to reflect an increase in capillary surface area due to physical training.

Key Words:

• capillary diffusion capacity
• iodide clearance
• muscles
• blood supply
• radioisotopes
• physical training
• xenon clearance