1. Total and nutritional flow in the fingertip were investigated during reflex sympathetic nerve stimulation (total body cooling) or adrenergic nerve transmitter administration. Nutritional flow was measured by the disappearance rate of a local depot of Na131 I, and total fingertip flow by venous occlusion plethysmography.
2. With body cooling the decrease in nutritional flow was not significant, but total and therefore arteriovenous shunt flow decreased significantly.
3. Norepinephrine infused into the brachial artery decreased total and nutritional flow significantly although total flow decreased more than nutritional.
4. It is concluded that sympathetic nervous system activity exerts a greater effect on finger arteriovenous shunt flow than on nutritional flow. Therefore nutritional flow is not adversely affected.