In vitro metabolism of progesterone, androgens and estrogens by rainbow trout embryos

Petkam, Rakpong; Renaud, R; Freitas, Ana; Canário, Adelino V.M.; Leatherland, J. F.

doi:10.1023/b:fish.0000021867.71729.22

Cited by 8 publications

(5 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This decline is consistent with reports from other fish species that show concentrations of steroids within eggs decline following fertilization (progesterone‐ (Feist et al, ); estradiol‐ (Feist et al, ; Feist and Schreck, ; Hines et al, ; Rothbard et al, ); testosterone‐ (Feist et al, ; Feist and Schreck, ; Hines et al, ; Iwamatsu et al, ; Rothbard et al, ); cortisol‐ (Alsop and Vijayan, ; Barry et al, ; de Jesus et al, ; Fuzzen et al, ; Hwang et al, ; Jentoft et al, ; Sampathkumar et al, ). While the fate of these maternal steroids remains to be deciphered, metabolism is a likely plausible candidate as numerous studies have demonstrated that fish embryos possess a suite of enzymes capable of metabolizing numerous steroids (Antila, ; Hines et al, ; Khan et al, , ; Li et al, ; Petkam et al, ; Rowell et al, ; Yeoh et al, ). It has been hypothesized that the embryonic metabolism of modulation of steroid levels buffers the process of gonadal differentiation from the effects of maternal steroids (Feist et al, ).…”

Section: Discussionmentioning

confidence: 99%

“…Maternally derived steroids are detectable in unfertilized fish eggs with levels dropping very rapidly following fertilization (progesterone‐ (coho salmon, Oncorhynchus kisutch , Feist et al, 1996); estradiol‐ (tilapia, Oreochormis nilotica ), Rothbard et al, ), (Coho salmon, Oncorhynchus kisutch , Feist et al, ), (rainbow trout, Oncorhynchus mykiss , Feist and Schreck, ), (tilapia, Oreochormis nilotica , Hines et al, ); testosterone‐ (tilapia, Oreochormis nilotica , Rothbard et al, ), (coho salmon, Oncorhynchus kisutch , Feist et al, ), (rainbow trout, Oncorhynchus mykiss , Feist and Schreck, ), (tilapia, Oreochormis nilotica , Hines et al, ), (medaka, Oryzias latipes , Iwamatsu et al, ); cortisol‐ (Japanese flounder, Paralichthys olivaceus , de Jesus et al, ), (tilapia, Oreochormis nilotica , Hwang et al, ), (Asian seabass, Lates calcarifer , Sampathkumar et al, ), (rainbow trout, Oncorhynchus mykiss , Barry et al, ), (yellow perch, Perca flavescens , Jentoft et al, ), (zebrafish, Danio rerio , Alsop and Vijayan, ), (rainbow trout, Oncorhynchus mykiss , Fuzzen et al, )). This decline in steroid concentrations is thought to be due to embryonic steroid metabolism since fish embryos possess a number of metabolic enzymes (Antila, ; Hines et al, ; Khan et al, , ; Li et al, ; Petkam et al, ; Rowell et al, ;). While the metabolism of maternal steroids by developing embryos may produce inactive metabolites in some situations, it is possible that the metabolites of maternal steroids may themselves be biologically active or could serve as precursors for steroid production later in development (Paitz and Bowden, ).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Changes in the concentrations of four maternal steroids during embryonic development in the threespined stickleback (Gasterosteus aculeatus)

et al. 2015

View full text Add to dashboard Cite

Embryonic exposure to steroids often leads to long-term phenotypic effects. It has been hypothesized that mothers may be able to create a steroid environment that adjusts the phenotypes of offspring to current environmental conditions. Complicating this hypothesis is the potential for developing embryos to modulate their early endocrine environment. This study utilized the threespined stickleback (Gasterosteus aculeatus) to characterize the early endocrine environment within eggs by measuring four steroids (progesterone, testosterone, estradiol, and cortisol) of maternal origin. We then examined how the concentrations of these four steroids changed over the first 12 days post fertilization (dpf). Progesterone, testosterone, estradiol, and cortisol of maternal origin could be detected within unfertilized eggs and levels of all four steroids declined in the first 3 days following fertilization. While levels of progesterone, testosterone, and estradiol remained low after the initial decline, levels of cortisol rose again by 8 dpf. These results demonstrate that G. aculeatus embryos begin development in the presence of a number of maternal steroids but levels begin to change quickly following fertilization. This suggests that embryonic processes change the early endocrine environment and hence influence the ability of maternal steroids to affect development. With these findings, G. aculeatus becomes an intriguing system in which to study how selection may act on both maternal and embryonic processes to shape the evolutionary consequence of steroid-mediated maternal effects.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Changes in the concentrations of four maternal steroids during embryonic development in the threespined stickleback (Gasterosteus aculeatus)

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The outstanding feature of estrogen metabolism in the equine embryo proper was the preferential expression of the oxidative form of 17b-HSD (type 2), converting E 2 to E 1 , has also been found in studies on fish embryos in both Arctic charr (Khan et al 1997) and rainbow trout (Petkam et al 2002). This conversion was less pronounced than seen with the extraembryonic tissues, especially the trilaminar Y-S wall, but clearly demonstrated an ability of the embryo proper to regulate the degree of exposure to the more biologically active estrogen.…”

Section: Discussionmentioning

confidence: 71%

“…The presence of these polar products was less noticeable when E 1 was the substrate; metabolism to the unidentified peak (not 17a-E 2 ) between E 1 and E 2 may have been partly responsible. Lastly, evidence of enzyme activity leading to conjugation of estrogens, as steroid sulfates, glucuronidates, and other forms (perhaps with glutathione) by the embryo proper has a parallel in the formation of similar products by fish embryos in Arctic charr (Khan et al 1997), and in rainbow (Petkam et al 2002), and steelhead (Yeoh et al 1996) trout. A marked conversion of E 2 to E 1 , followed by preferential metabolism of E 1 to its conjugated forms provides protection from exposure to potentially mutagenic products derived from E 2 .…”

Section: Discussionmentioning

confidence: 99%

Estrogen metabolism by the equine embryo proper during the fourth week of pregnancy

Raeside

Christie²,

Waelchli³

et al. 2009

Reproduction

View full text Add to dashboard Cite

Estrogen production by the trophoblast is considered important in early equine pregnancy and leads to high concentrations in yolk-sac (Y-S) fluid. The embryo proper is a potential site for their action. We examined estrogen metabolism in the embryo proper because some actions of estrogens are derived from locally formed metabolites. The embryo proper, as well as separated extraembryonic tissues, of conceptuses collected about day 25 of pregnancy, were incubated with 3[H]-estrone (E 1 ) and 3 [H]-estradiol (E 2 ). Steroids were recovered from media by solid-phase extraction and eluted separately as unconjugated and conjugated fractions. Profiles of free and sulfo-conjugated fractions were obtained by HPLC. Some differences and similarities were noted for the embryo proper as compared to the extraembryonic tissues. No reduction of E 1 to E 2 was noted for the embryo proper and allantois, but some was seen with the bilaminar Y-S wall. Less conversion of E 2 to E 1 occurred in the embryo proper than in the extraembryonic tissues. Profiles for hydrolyzed sulfates from incubation of the embryo proper were very similar for both substrates, mainly with E 1 present. Thus, low levels of reductase and high levels of oxido-activities were apparent for the 17b-hydroxysteroid dehydrogenase enzymes. Further evidence of an active role for the embryo proper was seen as minor, polar products, and an unknown compound eluting between E 2 and E 1 . These findings show, for the first time, that the embryo proper can metabolize estrogens that are found in Y-S fluid -a function of potential significance at this stage in its development.

show abstract

“…Both shbgb and cyp19a1a are expressed in granulosa cells, which are the main source of estrogens in the salmonid ovary (Planas et al, ). As their expression in the differentiating ovary is high at a time when testosterone and 17β‐estradiol metabolism is active (Petkam et al, ), Shbgb could serve to protect both from being degraded. Shbgb could also restrict the availability of testosterone as a substrate for aromatase, leaving the alternative substrate, androstenedione (Sire and Dépêche, ), more available for conversion by the enzyme.…”

Section: Discussionmentioning

confidence: 99%

Sex hormone‐binding globulins characterization and gonadal gene expression during sex differentiation in the rainbow trout, Oncorhynchus mykiss

Marivin

Yano

Guérin

et al. 2014

Molecular Reproduction Devel

View full text Add to dashboard Cite

Sex hormone-binding globulin (SHBG) binds androgens and estrogens in the blood of many vertebrates, including teleost fish. In mammals, SHBG is synthetized in the liver and secreted into the blood. In fish, shbga also exhibits a hepatic expression. In salmonids, in which the gene has been duplicated, the recently discovered shbgb gene exhibits a predominantly ovarian expression. The present work aimed at gaining new insight into shbgb gene structure and expression during gonadal sex differentiation, a steroid-sensitive process, and Shbgb protein structure and binding characteristics; specifically, rainbow trout (Oncorhynchus mykiss) shbgb was analyzed. shbgb structure was analyzed in silico while expression was characterized during gonadal sex differentiation using all-male and all-female populations. We observed that shbgb gene and cognate-protein structures are similar to homologs previously described in zebrafish and mammals. The shbgb gene is predominantly expressed in differentiating female gonads, with increased expression around the end of ovarian differentiation. In the ovary, shbgb mRNA was detected in a subset of somatic cells surrounding the ovarian lamellae. Furthermore, Shbgb binds steroids with a higher selectivity than Shbga, exhibiting a higher affinity for estradiol compared to Shbga. In conclusion, Shbgb binding characteristics are clearly different from those of Shbga. Shbgb is expressed in the differentiating ovary during a period when the synthesis and action of testosterone and estradiol must be tightly regulated. This strongly suggests that Shbgb participates in the regulation of steroid metabolism and/or mediation, that is, needed during early gonadal development in rainbow trout.

show abstract

In vitro metabolism of progesterone, androgens and estrogens by rainbow trout embryos

Cited by 8 publications

References 26 publications

Changes in the concentrations of four maternal steroids during embryonic development in the threespined stickleback (Gasterosteus aculeatus)

Changes in the concentrations of four maternal steroids during embryonic development in the threespined stickleback (Gasterosteus aculeatus)

Estrogen metabolism by the equine embryo proper during the fourth week of pregnancy

Sex hormone‐binding globulins characterization and gonadal gene expression during sex differentiation in the rainbow trout, Oncorhynchus mykiss

Contact Info

Product

Resources

About