Purification and analysis of a proteinaceous aphrodisiac pheromone from hamster vaginal discharge.

Hormonally regulated proteinaceous material secreted in hamster vaginal discharge is detected via the vomeronasal organ and elicits copulatory behavior in males. The major soluble protein in estrous vaginal discharge has been isolated, characterized by molecular weight and amino acid content, and shown to have substantial aphrodisiac activity. The aphrodisiac activity of the purified protein is abolished by heating or proteolysis, and the native protein retains the activity after procedures for removing possible ligands such as volatile odorants, steroids, and peptides. This evidence that the protein is a reproductive pheromone indicates that the mammalian vomeronasal organ can mediate sensory detection of behaviorally relevant macromolecules.