The Myonecrotic Effect of Duvernoy's Gland Secretion of the Snake Thamnophis elegans vagrans

Abstract

Duvernoy's gland is a sero-mucous or serous gland occurring in many species of colubrid snakes (Taub, 1967). The gland is usually located above the angle of the mouth deep to the supralabial scales, near the posterior pole of the maxilla. Its single duct opens near the most posterior maxillary teeth, which are enlarged or bladelike in many colubrids (Wright et al., 1979). The action of Duvernoy's gland secretion has attracted wide attention, because many instances of apparent envenomation have been reported (McKinstry, 1978). Although investigation into the toxic and clinical aspects of the secretion has begun (Vest, 1981; Rosenberg et al., 1985), it is not widely appreciated that the secretion is myonecrotic. This is of interest not only from the clinical standpoint, but for the understanding of the evolution of ophidian venoms, since Duveroy's gland shares many characteristics with the venom glands of viperid and elapid snakes (Kochva, 1965; Kardong, 1979, 1980; Ovadia, 1984). To evaluate the myonecrotic nature of Duvernoy's gland secretion, samples from the wandering garter snake Thamnophis elegans vagrans were here injected into mice and the effects qualitatively described.