Summavielle, TeresaMonteiro, Pedro Ribeiro RochaReis-Henriques, Maria ArmandaCoimbra, JoãoMonteiro, PedroSummavielle, Teresa2025-05-092025-05-092003-09-30Summavielle, T., Monteiro, P. R. R., Reis-Henriques, M. A., & Coimbra, J. (2003). In vitro metabolism of steroid hormones by ovary and hepatopancreas of the crustacean Penaeid shrimp Marsupenaeus japonicus. Scientia Marina, 67(3), Artigo 3. https://doi.org/10.3989/scimar.2003.67n3299http://hdl.handle.net/10400.22/30058Radioimmunoassay (RIA) was applied to identify selected metabolites obtained in in vitroincubations of ovarianand hepatopancreatic tissues from female Marsupenaeus japonicusin previtellogenic and vitellogenic maturation stages. Depend-ing on the precursors used, progesterone, 17α-hydroxyprogesterone or testosterone, it was possible to observe the presence of sev-eral enzymatic activities through metabolites detected in incubations. The present study provides evidence that the ovary of theshrimpM. japonicusis capable of synthesising 17β-estradiol from progesterone, evidencing the presence of 17α-hydroxy-lase, C17-C20lyase, 17β-hydroxysteroid dehydrogenase (17β-HSD) and aromatase. Enzymatic activities of aromatase, 3β-HSD and 17α-hydroxylase were detected in hepatopancreas, but not that of C17-C20lyase. These results suggest that 17β-estradiol could be the vitellogenesis stimulating ovarian hormone (VSOH), and together with former in vivoand in vitrostudies this leads us to propose that in fact there may be a physiological role for steroid hormones in the maturation cycleof crustaceans.engCrustaceanDecapodsHepatopancreasHormonesMaturationOvaryReproductionSteroidsresearch article10.3989/scimar.2003.67n3299