Postovulatory steroidogenesis after ovulation induced by LH or FSH in hypophysectomized pro-oestrous hamsters
in ReproductionSearch for other papers by K. Taya in
Current site
Google Scholar
PubMed
Search for other papers by G. S. Greenwald in
Current site
Google Scholar
PubMed
Summary. Hamsters hypophysectomized (hypox.) and concurrently injected i.p. with 2·5 μg ovine LH or 25 μg ovine FSH at 13:00 h on the day of pro-oestrus ovulated the normal complement of ova the next morning (Day 1). At 09:00 h on Day 1, serum levels of progesterone were comparable between sham-hypox. and LH-treated hypox. hamsters. In contrast, there were no differences in serum progesterone between FSH-treated or saline-treated hypox. hamsters; a slight but significant increase in serum progesterone occurred at 15:00 h in the FSH-treated animals and this was continued on Day 2, when values were comparable to those in the LH-treated and sham-hypox. hamsters.
The CL induced by LH or FSH produced significant amounts of progesterone in vitro on Day 1 at 09:00 and 15:00 h. On Day 2, there was a significant increase in production of progesterone by the CL of both groups. Production rates of progesterone by CL in vitro were the same in the LH- and FSH-treated animals on Days 1 and 2. Therefore, once ovulation has occurred in the hamster the newly developed CL gain the ability to synthesize, store and secrete progesterone independently of pituitary hormones for 2 days, although at a delayed rate after FSH treatment.
The results of incubations of the non-luteal (residual) ovarian tissues showed that large quantities of progesterone (about 7 ng/mg/h) were produced on Day 1 by tissue from FSH-treated animals while that of LH-treated hamsters lost progesterone at the rate of about 1 ng/mg/h. In saline-treated hypox. hamsters the residual tissue produced large amounts of progesterone and small amounts of oestradiol-17β and testosterone in vitro for at least 2 days after hypox. Little oestradiol-17β was produced by the CL of hamsters treated with LH, FSH or sham-hypox. By Day 2 the CL of all 3 groups produced appreciable amounts of testosterone in vitro, whereas on Day 1 only the CL induced by LH secreted testosterone.
Reproduction is committed to supporting researchers in demonstrating the impact of their articles published in the journal.
The two types of article metrics we measure are (i) more traditional full-text views and pdf downloads, and (ii) Altmetric data, which shows the wider impact of articles in a range of non-traditional sources, such as social media.
More information is on the Reasons to publish page.
| Sept 2018 onwards | Past Year | Past 30 Days | |
|---|---|---|---|
| Full Text Views | 215 | 63 | 4 |
| PDF Downloads | 74 | 31 | 3 |
Online ISSN: 1741-7899
Print ISSN: 1470-1626
Strengthening biomedical communities
to advance science and health
CONTACT US
Bioscientifica Ltd | Starling House | 1600 Bristol Parkway North | Bristol BS34 8YU | UK
Bioscientifica Ltd | Registered in England no 3190519