Regional Blood Flow in Skeletal Muscle Measured by the Heated Thermocouple Method during Electrical Nerve Stimulation of the Canine Gracilis Muscle

SHICHINO, K., YUKIMURA, T., MIURA, K., YAMAMOTO, K., OKUBO, M. and SHIMAZU, A. Regional Blood Flow in Skeletal Muscle Measured by the Heated Thermocouple Method during Electrical Nerve Stimulation of the Canine Gracilis Muscle. Tohoku J. Exp. Med., 1991, 164 (2), 145-156 - Skeletal muscle blood flow (MBF) and intramuscular pressure (IMP) were measured using a heated thermocouple (HTC) and a solid-state catheter-tip transducer during electrical nerve stimulation in the gracilis muscle of anesthetized dogs. MBF values obtained simultaneously by the HTC method and the inhalated hydrogen gas (H2) clearance method showed an excellent linear regression with a correlation coefficient of 0.93. Electrical nerve stimulation at frequencies of 5 and 100Hz increased total MBF, determined by an electromagnetic flowmeter, over control values 6.57±0.82 and 6.32±0.93ml/min/100g, respectively. Regional MBF at 5Hz stimulation determined with HTC increased in the same magnitude both at the midpoint and the distal portion of the gracilis muscle. However, following 100Hz stimulation, MBF at the midpoint was decreased from 8.15± 1.55 to 4.09±1.54ml/min/100g, whereas at the distal portion flow was increased from 6.39±1.71 to 21.2±5.29ml/min/100g. IMP in both regions was low and approximately 2.0mmHg at rest. IMP was remarkably increased to 27.9±8.43mmHg at the midpoint but not in the distal portion during 100Hz tetanic contraction, but showed no significant change in either region following 5Hz stimulation. These data suggest that HTC can serve to measure MBF, and that following 100Hz tetanic contraction, increased IMP may be associated with decreased regional MBF, irrespective of a total increase in flow in the gracilis muscle.