Hormonal Induction of Female Sexual-Behavior in Male and Female Hamsters
High levels of lordosis behavior were observed in female golden hamsters (Mesocricetus auratus) after 15 consecutive daily injections of 6.6 ?g estradiol benzoate (EB). In a second experiment, when males were similarly injected they showed lower, but reliable, levels of lordosis. In males, repeated testing indicated that a high level of responsivity was present after 6 days of EB (6.6 ?g) treatment, while the lordosis behavior of oil-injected males remained very low during repeated tests. In these experiments the lordosis responses of EB-primed hamsters of both sexes was further enhanced when progesterone (5.0 mg) was injected 4 hr before testing. In a third experiment, males that received EB-priming (6,6 or 666 ?g) for 48 hr and progesterone 4 hr before testing again showed increases in lordosis behavior, but the level of lordosis was not related to the dose of EB administered. Males receiving EB treatment (6.6 or 666 ?g) followed by oil were not significantly more responsive after 48 hr of treatment than males receiving only oil injections.
A very low, but apparently reliable level of lordosis was observed in untreated or oil-treated castrated male hamsters. Untreated female hamsters rarely showed lordosis behavior following ovariectomy.