Factor VIII complex in canine plasma after submaximal treadmill exercise.

Exercise-induced changes in the plasma concentrations of coagulation factor VIII and von Willebrand factor were evaluated, using 8 random-source adult dogs that exercised on a treadmill for 5 to 10 minutes (mean running time = 8.3 minutes). Maximum treadmill speeds attained by the dogs were 11 to 18 km/hr, and the mean of the maximum individual speeds was 14.3 km/hr. Maximum heart rates of individual dogs during exercise were 190 to 250 beats/min with a mean of 218 beats/min (a 2.4-fold increase over the mean preexercise rate). Exercise did not induce significant increases in plasma concentrations of factor VIII coagulant activity, coagglutinin co-factor activity, or factor VIII-related antigen. Results indicated that submaximal exercise does not induce increases in plasma concentrations of coagulation factor VIII or von Willebrand factor in the dog.