LOSS OF COLLAGEN FROM THE UTERUS OF THE RAT AFTER OVARIECTOMY AND FROM THE NON‐PREGNANT HORN AFTER PARTURITION

1. Loss of collagen from the uterus of the rat after spaying, and from a non‐pregnant horn after parturition has been investigated. 2. Loss of collagen from a non‐pregnant horn after parturition proceeds rapidly, at about the same rate as loss of collagen from the uterine cervix after parturition. 3. After spaying, loss of collagen from the uterus proceeds much more slowly than after parturition, and more slowly than loss of weight and non‐collagenous protein N. 4. An incidental finding was that the number of foetal sites in the horn of the opposite side after unilateral spaying was approximately the same as in both horns, i.e. double that normally found in a single horn.