The isolated nictitating membrane of the cat. A new model for the study of narcotic analgesics.

Kinetic parameters of morphine and azidomorphine derivatives as well as methionine enkephalin methylester were determined on the electrically stimulated isolated medial smooth muscle of the cat nictitating membrane. The organ was found to be a promising in vitro model for testing the action of opiate agonists on opiate B receptors.