Contemporary topics in laboratory animal science / American Association for Laboratory Animal Science
-
Contemp Top Lab Anim Sci · Nov 2005
Comparative StudyLack of correlation of vaginal impedance measurements with hormone levels in the rat.
Hormone levels vary in female rats depending on estrous cycle stage. Vaginal cytology is a reliable method of staging female rats, but vaginal impedance offers an alternative depending on application. We sought to correlate vaginal impedance in cycling female rats with hormone levels. ⋯ No correlation occurred between vaginal impedance and hormone levels in unstaged rats (n = 41). Two animals evaluated for reproductive tract histology showed evidence of pseudopregnancy. Vaginal impedance may be useful in distinguishing estrus from nonestrus rats but may be limited for chronic estrous cycle monitoring because of the possible risk of inducing pseudopregnancy.