This collaborative research project uses a combination of chemical, behavioral, and endocrinological methods to identify pheromones that regulate male copulatory behavior, reduce intermale aggression and cause a rapid increase in circulating male hormone levels. A chemical stimulus for copulatory behavior has been isolated from a water-soluble, deodorized, macromolecular fraction of hamster vaginal discharge. It appears to consist of two proteins of molecular weights 17,000 and 35,000 that are detected by the male hamster in the vomeronasal organ. These and other active compounds of the macromolecular fraction will be chemically characterized. This work is part of a long term program to investigate the possibilities that pheromones in mammals may be distinguished from other intraspecific chemical signals, such as odors or perfumes, by their interaction with specialized receptors and that, as part of a specialized communication system, pheromones will vary chemically in only limited ways between different mammalian species. In several species such as the hamster, pheromones, acting in minute amounts, are known to have rapid and specific effects on hormone levels. It is not known whether such effects occur in humans, but the possibility needs to be investigated. The implications of such research, for example in therapy of disease conditions involving hormonal imbalance, are enormous.
