Muscle blood flow in cats: comparison of microdialysis ethanol technique with direct measurement.
A quantitative validation of the microdialysis ethanol technique was performed in cat gastrocnemius muscle. Six to eight microdialysis probes were inserted into the isolated muscle preparation and perfused (0.5-10.0 microliters/min) with Krebs-Henseleit buffer containing between 5 and 1,000 mmol/l ethanol. Skeletal muscle blood flow was held constant in the range of 4-99 ml.100 g-1.min-1 by a servo-controlled roller pump and was determined with the microdialysis ethanol technique as well as by timed collection of venous outflow. The ethanol concentration outflow-to-inflow ratio ([ethanol]collected dialysate/[ethanol]infused perfusion medium) decreased in a nonlinear fashion when microdialysis perfusion flow rates of 0.5 and 1.0 microliter/min were employed. However, a linear decrease was found between 4 and approximately 45 ml.100 g-1.min-1 (r = -0.92 to -0.99). The lower outflow-to-inflow ratio was at 4 ml.100 g-1.min-1 (i.e., due to a low probe perfusion flow rate or a large dialysis membrane), the greater the sensitivity of the method was. It is concluded that this nonradioactive technique provides a simple and valid method for determining nutritive blood flow in skeletal muscle.
Hickner
R C
RC
Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.
Ekelund
U
U
Mellander
S
S
Ungerstedt
U
U
Henriksson
J
J
D000818:Animals; D002415:Cats; D004058:Diffusion; D000431:Ethanol; D005260:Female; D017551:Microdialysis / Q000295:instrumentation / Q000379:methods*; D018482:Muscle, Skeletal / Q000098:blood supply*; D012039:Regional Blood Flow / Q000502:physiology; D012044:Regression Analysis
D000431:Ethanol