Summary. The quiescent corpus luteum of female tammars was reactivated by removal of the pouch young (RPY). The reactivated corpus luteum was ablated 3 days after RPY. Plasma progesterone and oestradiol concentrations were measured by radioimmunoassay in these and in sham-operated controls. Excision of the CL abolished the rise in progesterone seen at Day 5–6 in the sham-operated animals (130·7 ± 56·6 vs 452·4 ± 176·0 pg/ml, mean ± s.d.). By contrast, oestradiol-17β values increased within 6–16 h of CL excision to 16·3 ± 6·9 pg/ml and remained high for 1–3 days while in the sham-operated animals there were less sustained and more variable peaks of 10–20 pg/ml between Days 3 and 5 (mean 12·0 ± 3·6 pg/ml at Day 4–5). We conclude that the early transient increase in peripheral plasma of progesterone is of luteal origin but the source of the oestradiol remains unknown.
Keywords: corpus luteum; progesterone; oestradiol-17β; early pregnancy; marsupial
If the inline PDF is not rendering correctly, you can download the PDF file here.