Factors affecting the pheromone composition of voided boar saliva.

The pheromone binding protein 'pheromaxein' which binds the pheromonal 16-androstene steroids in the saliva of the male pig (boar), was degraded and lost its binding activity in saliva incubated in air for 72 h at 21 degrees C and 37 degrees C. However, pheromaxein and its binding activity were retained in saliva incubated for 168 h at 4 degrees C. When the 3H-labelled pheromones 5 alpha-androst-16-en-3 alpha-ol (3 alpha-androstenol), 5 alpha-androst-16-en-3-one (5 alpha-androstenone) and 5 alpha-androst-16-en-3 beta-ol (3 beta-androstenol) were incubated with boar saliva for 168 h at 21 degrees C, 3 alpha-androstenol was primarily converted to 5 alpha-androstenone and 5 alpha-androstenone to 3 beta-androstenol; 3 beta-androstenol was unchanged. Evidence was obtained for microorganisms being responsible for these steroid transformations.