Acute increase in plasma corticosterone level in female mice evoked by pheromones.

Exposure of a singly reared estrous female to grouped females or their bedding during 20 min resulted in an increase in the plasma corticosterone level during the first 10 min. The reaction of the adrenal glands was similar to the excitation evoked by stress connected with moving females from their own cage to a new, clean cage. The highest level of the adrenal hormone was present in estrous females after exposure to male bedding during 10 min. This was followed by a dramatic decrease during the next 90 min. It is suggested that male pheromones, through activation of the pituitary-adrenal system and acute release of corticosterone, participate in the stimulation of sexual behavior in receptive female mice.