Relationship of fetal gonads to urinary estrogen excretion by the pregnant mare
Raeside, J.I.; Liptrap, R.M.; Milne, F.J.
American Journal of Veterinary Research 34(6): 843-845
1973
ISSN/ISBN: 0002-9645 PMID: 4707571 Document Number: 66975
Removal of both foetal gonads (3 male, 2 female foetuses) in 5 pregnant mares resulted in a rapid decrease in urinary oestrogen excretion to very low concentrations. In 2 or 4 mares in which one foetal gonad (4 male foetuses) was removed by surgical operation, the amounts of urinary oestrogens decreased to approximately one-half of the preoperative concentrations. In 3 mares subjected to sham operation, there was little or no decrease in urinary oestrogen excretion. Seemingly, foetal gonads are involved in some way in the production of oestrogens by the pregnant mare. In addition, absence of foetal gonads seemed implicated in most of the abortions which occurred after foetal gonadectomy.