Concentrations of oestradiol-17 beta in plasma and corpora lutea throughout pregnancy in the tammar, Macropus eugenii.
Oestradiol-17 beta concentrations were measured by radioimmunoassay in peripheral blood samples from 10 tammar wallabies after their pouch young were removed to terminate embryonic diapause. Oestradiol concentrations rose from 8.3 +/- 1.2 pg/ml on Days 3 and 4 to peak of 15.8 +/- 2.9 pg/ml on Day 5, coincident with an increase in 'progesterone' concentrations, and then fell to 10.5 +/- 2.7 pg/ml on Day 7. No changes in oestradiol concentrations were associated with parturition. Five females came into oestrus and mated 9.8 +/- 6.1 h post partum; peak concentrations of plasma oestradiol (20.9 +/- 2.1 pg/ml) occurred around the time of mating. None of the females that did not mate up to the end of the experiment at Day 30 had a rise in plasma oestradiol concentrations. Corpora lutea contained 20-100 pg oestradiol during pregnancy. The highest ovarian oestradiol content (greater than 1200 pg) was measured in whole ovaries containing Graafian follicles from full-term pregnant females. The rise in oestradiol concentrations at Day 5 may be important in the termination of diapause. The post-partum increase in plasma oestradiol concentrations coincides with oestrus. The source of this oestrogen appears to be the preovulatory follicle.
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003338:Corpus Luteum / Q000378:metabolism*; D004958:Estradiol / Q000097:blood / Q000378:metabolism*; D005260:Female; D007614:Macropodidae / Q000378:metabolism*; D008394:Marsupialia / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000097:blood
D011374:Progesterone; D004958:Estradiol