N. Yamamura et al., Expression of messenger RNA for gonadotropin receptor in the granulosa layer during the ovulatory cycle of hens, COMP BIOC A, 129(2-3), 2001, pp. 327-337
Citations number
49
Categorie Soggetti
Animal Sciences",Physiology
Journal title
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY
The present experiments were conducted to evaluate the mRNA levels of lutei
nizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FS
HR) in granulosa layers during the ovulatory cycle of hens, in relation to
the release of LH and steroid hormones. After the release of LH, progestero
ne (P4) and estradiol-17 beta (E2), found 4-5 h before ovulation, LHR and F
SHR mRNA levels were observed to decrease in the granulosa layers of the la
rgest (F1) and second largest (F2) preovulatory follicles, with the greates
t in the LHR mRNA level of FI. PI concentrations in the granulosa layers of
Fl and F2 increased 4-5 h before ovulation, with greater in Fl than in F2.
F2 concentrations in the theca layers were greater in F2 than in F1 throug
hout the ovulatory cycle. Also, the injection of ovine LH caused decreases
in the mRNA levels of LHR and FSHR in the granulosa layers. However, these
decreases were abolished by the injection of aminoglutethimide, an inhibito
r of steroid synthesis. These results suggest that in hen granulosa cells,
the mRNA levels of not only LHR but also FSHR are down-regulated by LH and
the down-regulation may be mediated steroid hormones. (C) 2001 Elsevier Sci
ence Inc. All rights reserved.