Effects of voluntary and forced exercise on lordosis behavior in female rats.
We measured sexual behavior (lordosis) in ovariectomized, steroid-treated, exercising female rats. When estradiol-treated animals exercised voluntarily, lordosis was directly related to the amount of exercise. Forced exercise (swimming) following treatment with estradiol 17 beta and progesterone significantly increased lordosis scores but only after animals swam for 2.5 hr per day. Lordosis behavior returned to baseline levels 7 weeks after forced exercise was stopped. Circulating levels of estrogen and progesterone measured immediately after behavioral testing did not differ between animals forced to exercise and their controls. The mechanisms responsible for the increase in lordosis behavior following exercise are unclear. It is possible that a change in body composition, a change in neural sensitivity to gonadal steroids, and/or changes in pituitary or adrenal function contribute to the increased lordosis behavior in exercised animals.
Axelson
J F
JF
Psychology Department, Holy Cross College, Worcester, Massachusetts 01610.
Sawin
C
C
D000818:Animals; D005260:Female; D010052:Ovariectomy; D005082:Physical Exertion; D011187:Posture; D051381:Rats; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013550:Swimming