INVESTIGADORES
SOMOZA Gustavo Manuel
congresos y reuniones científicas
Título:
Cortisol and sex differentiation: the 11β-hydroxysteroid dehydrogenase as a key enzyme.
Autor/es:
GUSTAVO M. SOMOZA; JUAN I. FERNANDINO; RICARDO S. HATTORI; CARLOS A. STRÜSSMANN
Lugar:
Querétaro
Reunión:
Congreso; NASCE 2013: The second meeting of the North American Society for Comparative Endocrinology.; 2013
Institución organizadora:
North American Society of Comparative Endocrinology
Resumen:
In recent years, fish
have been extensively studied because they present a variety of mechanisms of
sex determination/differentiation. In the present work we review the sex
determining mechanisms and the testicular differentiation process in Odontesthes bonariensis, commonly known
as pejerrey, in relation to temperature-induced masculinization. We have
recently shown that cortisol is involved in the gonadal masculinization process
of pejerrey during early development. Larvae exposed to a male-producing
temperature showed increased whole-body cortisol and developed as males.
Moreover, they also have high 11-KT levels, suggesting a relation between cortisol
and 11-oxygenated androgens during the masculinization process.
11β-hydroxysteroid
dehydrogenase (11β-HSD) is one of enzymes shared by the glucocorticoid and
androgen pathways. This enzyme converts cortisol to cortisone and also
participates in the finals steps of the synthesis of the 11-oxigenated
androgens. In pejerrey, during the critical period of sex determination, gene
expression of the 11β-HSD gene hsd11b2,
glucocorticoid receptors gr1, and
androgen receptors (ar1 and ar2) were shown to be increased and expressed in
the gonads during masculinization. These data suggest that the enzymatic
machinery necessary for the local production of 11-oxygenated steroids and the
inactivation of cortisol is active in the undifferentiated gonads during sex
determination. Also, gonadal explants incubated in the presence of cortisol showed
an increase in the synthesis of 11-KT. Based on these data, and also from data
taken from the literature we here propose that the masculinization induced by
thermal stress can be considered as a consequence of cortisol inactivation and
the concomitant synthesis of 11-KT and discuss this as a possible mechanism of
masculinization induced by different types of environmental stressors.
Supported by CONICET
and ANPCyT (Argentina) and the Ministry of Education, Culture, Sports, Science
and Technology of Japan.