Comparative investigations of aspirin and indomethacin effects on blood flow in the vascular bed of skeletal muscles at rest and during muscle contractions in dogs and cats.

The effecs of two different inhibitors of prostaglandin synthesis--aspirin and indomethacin--on the blood flow in the vascular bed of the hindleg of vagotomized animals were studied before, during and after muscular activity of this limb. The responses of resistance and capacitance vessels were recorded simultaneously. Muscular contractions were evoked stimulating electrically (4 impulses/second) the peripheral part of the sciatic nerve. It was found that both inhibitors reduced exercise hyperaemia and postexercise hyperaemia. The response of the capacitance vessels was also reduced during muscular contractions. The obtained results confirmed that endogenous prostaglandins participate in the vascular response during exercise in the precapillary and postcapillary sections of microcirculation in the muscles. The particularly important effect of aspirin on postexercise hyperaemia in dogs in relation to cats is stressed.