Our previous studies have demonstrated that macromolecular fractions of hamster
vaginal discharge elicit intense genital investigation and facilitate copulatory behavior toward anesthetized males (female surrogates) whose hindquarters have been scented with these fractions, and that the
aphrodisiac activity is significantly reduced in the
vaginal discharge of ovariectomized (
OVEX) or hypophysectomized (HYPOX) females. The present series of studies compared the
protein compositions of estrous, diestrous,
OVEX, and HYPOX
vaginal discharge, and assessed whether protein digestion of estrous
vaginal discharge affects its
aphrodisiac activity.
Polyacrylamide gel electrophoresis of vaginal lavages showed that the endocrine status of females has a profound effect on the
protein composition of the
vaginal discharge. The concentration of the major
proteins dropped by about ten-fold in going from the estrous to the diestrous condition. The concentration of these same
proteins appear to be at least another order of magnitude lower in the
vaginal discharges of
OVEX and HYPOX females. These major
proteins had molecular weights greater than 10,000 Daltons. A macromolecular fraction of estrous
vaginal discharge isolated by gel filtration at elevated temperature (conditions known to separate some
protein-bound
steroids) and containing
proteins of molecular weight greater than 10,000 Daltons was found to be modestly but significantly less active than estrous discharge in its ability to elicit intense genital investigation, and not significantly different from estrous discharge in its ability to facilitate overt copulatory behavior toward scented surrogates.
Pronase digestion of the
proteins in this fraction did not alter its effects on investigatory behavior toward scented surrogates but significantly reduced its ability to facilitate copulatory behavior.(ABSTRACT TRUNCATED AT 250 WORDS)