Tesis doctoral de Gemma Janer Gual
Ninety-five percent of all animal species are invertebrates, and like vertebrates, they are susceptible to endocrine disruption. Nevertheless, there are important gaps on the knowledge of the endocrine system of invertebrates that hinder the understanding of the endocrine disruption phenomena in those species. steroid synthesis and metabolism is one of several possible targets of endocrine disruptors. This thesis aimed to characterize sex steroid metabolism in different invertebrate species, to test the in vitro effect of model endocrine disruptors in those species, and to test the in vivo effect of model endocrine disruptors on steroid levels and metabolism in species from a selected phyla (mollusca). The species investigated (mollusca: marisa cornuarietis, mytilus sp., And/or crassostrea virginica; crustacea: hyalella azteca; and echinoderma: paracentrotus lividus) were able to form a series of phase i metabolites of testosterone that are also formed by vertebrates, with the exception of 4-androstene-3[beta],17[beta]-diol, a metabolite formed by p. Lividus and h. Azteca. One of the major differences with vertebrate species was the lower contribution of hydroxylases in the metabolism of testosterone, and the metabolic fate of androstenedione in molluscs (5[alpha]-reduction instead of 17[beta]-reduction). Regarding phase ii metabolism of testosterone, sulfotransferases were found at high levels in p. Lividus, but low or undetectable levels were present in h. Azteca and the molluscan species investigated. in contrast, the conjugation of steroids with fatty acid moieties was present in all invertebrates investigated, showing that acyl-coa:steroid acyltransferases are well-conserved through evolution. Steroid levels and the enzymatic activities for some metabolic pathways showed differences between males and females, among tissues, and between seasons in some invertebrate species, which adds further evidence for a physiological role of sex ster
Datos académicos de la tesis doctoral «Steroid levels, steroid metabolic pathways and their modulation by endocrine disruptors in invertebrates«
- Título de la tesis: Steroid levels, steroid metabolic pathways and their modulation by endocrine disruptors in invertebrates
- Autor: Gemma Janer Gual
- Universidad: Autónoma de barcelona
- Fecha de lectura de la tesis: 07/11/2005
Dirección y tribunal
- Director de la tesis
- Cinta Porte Visa
- Tribunal
- Presidente del tribunal: joaquim Gutiérrez fruitós
- machado Santos Miguel (vocal)
- rodolfo Barreiro lozano (vocal)
- montse Solé rovira (vocal)