Norepinephrine-induced depolarization of skeletal muscle cells

I.v. administration of norepinephrine to anesthetized hamsters was followed by a significant depolarization of the cell membranes of skeletal muscle (gracilis anticus and sartorius). The occurrence of this depolarization in consistent with the suggestion that changes in ionic distribution across the cell membrane are associated with activation of non-shivering thermogenesis in muscle cells as has been proposed for brown adipocytes.