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 |
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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 -