Plasma inhibin levels in relation to steroids and gonadotrophins during oestrous cycle in buffalo

Citation
B. Singh et al., Plasma inhibin levels in relation to steroids and gonadotrophins during oestrous cycle in buffalo, REPROD DOM, 36(3-4), 2001, pp. 163-167
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences
Journal title
REPRODUCTION IN DOMESTIC ANIMALS
ISSN journal
0936-6768 → ACNP
Volume
36
Issue
3-4
Year of publication
2001
Pages
163 - 167
Database
ISI
SICI code
0936-6768(200108)36:3-4<163:PILIRT>2.0.ZU;2-Z
Abstract
The study was conducted on six Murrah buffalo synchronized and induced to o estrus. An indwelling, catheter was placed in the jugular vein of each buff alo 4 days before the expected onset of the oestrus following the induced o estrus and blood samples were collected at 8 h intervals from each animal t hroughout the oestrous cycle. Plasma immunoreactive inhibin, follicle-stimu lating hormone (FSH), luteinizing hormone (LH), estradiol-17 beta and proge sterone were estimated by radioimmunoassay to study the variations in the p eripheral levels of these hormones and their inter-relationships in order t o elucidate the feedback systems controlling them during the oestrous cycle of buffalo. Plasma inhibin levels ranged between 391.25 and 631.97 pg/ml d uring various phases of the oestrous cycle and were found to be higher than reported in cows. Peak LH and FSH levels during oestrus were 38.40 +/- 9.2 1 and 24.04 +/- 4.75 ng/ml, respectively and estradiol-17 beta and progeste rone were 19.50 +/- 5.51 pg/ml and 0.61 +/- 0.25 ng/ml, respectively. The m ean plasma inhibin concentration on the day of oestrus was 562.5 +/- 18.9 p g/ml. Levels of FSH in the plasma showed three mid-cycle elevations which c orresponded to comparatively lower inhibin and elevated estradiol-17 beta l evels during the same period. From this observation it was deduced that bot h inhibin and estradiol-17 beta have a feed-back regulatory effect on FSH s ecretion in buffalo.