Physiologische Untersuchungen an der innervierten glatten Muskulatur der Vogelfedern (Mm. pennarum)

The tension development of the smooth feather muscles of the pigeon was measured (a) on the wing in situ (b) on an isolated innervated skin preparation and (c) on an isolated muscle preparation. The contraction produced by nerve stimulation is biphasic. The second phase can be blocked by α-receptor blocking agents. The mechanism of the first phase is unknown. The preparation seems very suitable for the investigation of neuromuscular transmission in smooth muscle.