Normal female rats in parabiosis have a tendency to run oestrous cycles independent of each other. Though sufficient hormones are exchanged to disturb somewhat the oestrous cycles of each twin member this interference does not result in synchronized cycles. During pregnancy of one of the twins the oestrous cycle of the non-pregnant animal is almost entirely inhibited by the action of the corpus luteum hormone from the pregnant member. This same phenomenon persists after parturition as long as the mother nurses her litter, which must be due to the activity of the hormone of corpus luteum of lactation. Also the corpus luteum hormone in the pregnant member stimulates the mammary glands of the non-pregnant twin. These factors indicate that the corpus luteum hormone is stronger and more positive in action than the oestrous producing follicular hormone.
Proceedings of the Iowa Academy of Science
©1931 Iowa Academy of Science, Inc.
Hill, Robert T.
"Exchange of Oestrous and Corpus Luteum Hormones in Parabiotic Female Rats,"
Proceedings of the Iowa Academy of Science, 38(1), 287-287.
Available at: https://scholarworks.uni.edu/pias/vol38/iss1/103