Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide inhibit antigen

Interchangeable lens retaining means for photographic cameras, so designed that the interchangeable lens may be placed on or removed from the camera by a simple axial movement in the direction of the optical axis, without requiring the rotational or twisting movement required when a conventional bayonet type mount is used. Shoulders on the interchangeable lens are engaged by a plurality of pivoted latches on the camera, the parts being beveled so that the latches are automatically thrust aside as the interchangeable lens is brought toward its seated position on the camera, and then snap behind the retaining shoulders on the lens. The latches are coupled to each other so that all move in unison. A radially movable button on the lens operates a lever to disengage all of the latches on the camera, so that the lens may be removed axially from the camera.