Sex Chromosome Complement and gonadal steroid influences in the sexually dimorphic vasopressinergic system

VIVAS, L

Ribeirao preto, San Pablo.

Simposio; International Symposium ?Peripheral and central regulation of energy and fluid tonicity homeostasis; 2017

Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo.

This study aimed to define whether sex chromosome complement (SCC) and its interaction with gonadal steroids may differentially modulate sex differences in the vasopressin activity and gene expression in response to osmotic stimulation. In order to evaluate whether SCC may differentially modulate vasopressin gene expression we used mice of the "four core genotype" model, in which the effect of gonadal sex and SCC is dissociated, allowing comparisons of sexually dimorphic traits between XX and XY females as well as in XX and XY males. Comparing these genotypes, it is possible to segregate the role of a) SCC (comparing mice with the same gonadal type but different SCC: XX vs. XY) b) sex (females vs. male) and c) the interaction of SCC and sex. To remove the activational effects of sex hormones, that might mask the modulatory action of SCC and the organizational hormonal effects, mice were gonadectomized and 15 days later were submitted to a water deprivation protocol (DEP group). Control groups remained with access to water and normal diet (CON group). Twenty four hours later, brains and plasma of all groups were collected to assess plasma electrolytes and osmolality and to evaluate relative gene expression of AVP at the supraoptic (SON) and paraventricular nuclei (PVN).The statistical analysis showed a significant effect of treatment for both, osmolality and plasma Cl- levels {F(1,40)=4,91 p