Abstract
The red seabream Pagrus major is a useful experimental fish for studying the endocrine control of oogenesis in teleosts. This study investigated the steroidogenic pathway for estradiol-17β (E2) biosynthesis in the ovarian follicles of red seabream. Intact follicles were isolated during vitellogenesis and incubated in vitro with different radiolabeled steroid precursors. When 17-hydroxyprogesterone (17-P), dehydroepiandrosterone (DHEA), or androstenedione (AD) were used as precursors, both testosterone (T) and estrone (E1) were synthesized by follicles, leading to estradiol-17β (E2) production. Serum steroid levels measured by enzyme-linked immunosorbent assay showed that T, E1, and E2 were present in the circulation at levels ranging from 1 ng/mL to 2 ng/mL throughout the day during the spawning season. In vitro conversion of E1 into E2, however, was 15.8-fold greater than T conversion into E2, suggesting that E2 is synthesized mainly via E1 rather than T. The results showed that E2 was synthesized from pregnenolone via 17-hydroxypregnenolone, DHEA, AD, and E1. Thus, the study demonstrated the complete steroidogenic E2 synthesis pathway in the ovarian follicles of red seabream, and revealed that E1 is the major precursor of E2.
| Original language | English |
|---|---|
| Pages (from-to) | 680-687 |
| Number of pages | 8 |
| Journal | Fisheries Science |
| Volume | 68 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Jul 23 2002 |
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All Science Journal Classification (ASJC) codes
- Aquatic Science
Cite this
Biosynthesis of estradiol-17β in the ovarian follicles of the red seabream Pagrus major during vitellogenesis. / Ohta, Kohei; Yamaguchi, Sonoko; Yamaguchi, Akihiko; Okuzawa, Koichi; Gen, Koichiro; Kagawa, Hirohiko; Matsuyama, Michiya.
In: Fisheries Science, Vol. 68, No. 3, 23.07.2002, p. 680-687.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Biosynthesis of estradiol-17β in the ovarian follicles of the red seabream Pagrus major during vitellogenesis
AU - Ohta, Kohei
AU - Yamaguchi, Sonoko
AU - Yamaguchi, Akihiko
AU - Okuzawa, Koichi
AU - Gen, Koichiro
AU - Kagawa, Hirohiko
AU - Matsuyama, Michiya
PY - 2002/7/23
Y1 - 2002/7/23
N2 - The red seabream Pagrus major is a useful experimental fish for studying the endocrine control of oogenesis in teleosts. This study investigated the steroidogenic pathway for estradiol-17β (E2) biosynthesis in the ovarian follicles of red seabream. Intact follicles were isolated during vitellogenesis and incubated in vitro with different radiolabeled steroid precursors. When 17-hydroxyprogesterone (17-P), dehydroepiandrosterone (DHEA), or androstenedione (AD) were used as precursors, both testosterone (T) and estrone (E1) were synthesized by follicles, leading to estradiol-17β (E2) production. Serum steroid levels measured by enzyme-linked immunosorbent assay showed that T, E1, and E2 were present in the circulation at levels ranging from 1 ng/mL to 2 ng/mL throughout the day during the spawning season. In vitro conversion of E1 into E2, however, was 15.8-fold greater than T conversion into E2, suggesting that E2 is synthesized mainly via E1 rather than T. The results showed that E2 was synthesized from pregnenolone via 17-hydroxypregnenolone, DHEA, AD, and E1. Thus, the study demonstrated the complete steroidogenic E2 synthesis pathway in the ovarian follicles of red seabream, and revealed that E1 is the major precursor of E2.
AB - The red seabream Pagrus major is a useful experimental fish for studying the endocrine control of oogenesis in teleosts. This study investigated the steroidogenic pathway for estradiol-17β (E2) biosynthesis in the ovarian follicles of red seabream. Intact follicles were isolated during vitellogenesis and incubated in vitro with different radiolabeled steroid precursors. When 17-hydroxyprogesterone (17-P), dehydroepiandrosterone (DHEA), or androstenedione (AD) were used as precursors, both testosterone (T) and estrone (E1) were synthesized by follicles, leading to estradiol-17β (E2) production. Serum steroid levels measured by enzyme-linked immunosorbent assay showed that T, E1, and E2 were present in the circulation at levels ranging from 1 ng/mL to 2 ng/mL throughout the day during the spawning season. In vitro conversion of E1 into E2, however, was 15.8-fold greater than T conversion into E2, suggesting that E2 is synthesized mainly via E1 rather than T. The results showed that E2 was synthesized from pregnenolone via 17-hydroxypregnenolone, DHEA, AD, and E1. Thus, the study demonstrated the complete steroidogenic E2 synthesis pathway in the ovarian follicles of red seabream, and revealed that E1 is the major precursor of E2.
UR - http://www.scopus.com/inward/record.url?scp=0036314959&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036314959&partnerID=8YFLogxK
U2 - 10.1046/j.1444-2906.2002.00477.x
DO - 10.1046/j.1444-2906.2002.00477.x
M3 - Article
AN - SCOPUS:0036314959
VL - 68
SP - 680
EP - 687
JO - Fisheries Science
JF - Fisheries Science
SN - 0919-9268
IS - 3
ER -