An extremely sensitive and reliable bioassay for inhibin based on inhibition of ovine pituitary FSH secretion in vitro was developed and used to measure exogenous and endogenous inhibin activity in the ewe. The sheep inhibin bioassay is 30- to 40-fold more sensitive than conventional rat inhibin bioassays. The minimum sensitivity of each bioassay in the measurement of inhibin activity in 1 ml of sheep serum is 220 mu. and 4080 mu. in the sheep and rat bioassays respectively. This sensitive inhibin bioassay has permitted, for the first time, the measurement of endogenous inhibin in the peripheral and ovarian vein blood of the sheep, as well as exogenously administered inhibin.
The half-life of exogenously administered ovine inhibin (in follicular fluid) in the sheep was calculated as two components (18–24 and 50–60 min) from the inhibin profiles of six ewes. Inhibin contained in the ovine follicular fluid, given as a bolus i.v. injection, increased to maximum levels after 5 min and then remained increased for 10–32 min depending upon the dose administered, before exponentially decaying. The time for inhibin to exert its effect ranged from 3 to 6 h after injection and appeared to be dose-related. The bolus injection of inhibin, apart from causing suppression of FSH, evoked a large rebound increase of FSH up to 400% of preinjection levels.
The development of the sheep bioassay will allow the measurement of biologically active inhibin in the peripheral circulation and ovarian vein blood of sheep with the possibility of extending this to man.
J. Endocr. (1986) 110, 341–352
Journal of Endocrinology 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 | 1 | 0 | 0 |
| PDF Downloads | 1 | 0 | 0 |
Online ISSN: 1479-6805
Print ISSN: 0022-0795
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
