Independent Sympathetic Vasoconstrictor Innervation of Arterioles and Precapillary Sphincters

Arteriovenous extraction of rubidium‐86 was continuously recorded in isolated dog's gracilis muscle or cat's gastrocnemius‐plantaris muscles perfused with blood at constant flow. Perfusion pressure was also recorded. Two experiments are described which support the hypothesis of Bücherl and Schwab (1952) that from the central nervous system there is a separate nervous control of arteriolar and precapillary smooth muscles.