The second group (control) received pumps that contained saline on March 19. A terminal blood sample was taken by cardiac puncture under ketamine-promazine (Rogar STB, Montreal, PQ, Canada) anesthesia, and animals were killed with a single injection of T-61 euthanasia solution (Hoechst Canada, Regina, SK, Healthcare Canada). The ovaries were collected from 3 untreated pregnant animals every 2 days between March 19 and 31 and every 5 days thereafter until April 15, and also from 3 each of the bromocriptine- and saline-treated mink on alternate days from March 19 to 31. No differences were observed between untreated and saline-treated animals, so these groups were combined for statistical analysis and presentation.
In animals treated with bromocriptine, the CL were reduced to a size that rendered their dissection impossible. Analysis of whole ovaries was therefore effected in all animals. One ovary from each animal was placed in 4 M guanidine is-othiocyanate (Sigma) buffer containing 0.12 M of 2p-mer-captoethanol for total RNA isolation, while the other was snap frozen and stored at -70°C for receptor binding assay.