ROLE OF SEX CHROMOSOME COMPLEMENT AND THE ORGANIZATIONAL GONADAL HORMONAL EFFECTS IN THE VASOPRESSINERGIC PRESSOR AND ANTIDIURETIC SEXUAL DIMORPHIC RESPONSES

VIVAS L; GONZALEZ, L; CAEIRO, X.; GODINO, A

Mar del Plata

Congreso; Reunión Anual SAIC, SAI, SAFIS.; 2018

SAIC; SAI; SAFIS

Role of sex chromosome complement and the organizational gonadal hormonal effects in the vasopressinergic pressor and antidiuretic sexual dimorphic responses. Reunión Anual SAIC, SAI, SAFIS. 14-17 Noviembre de 2018. Mar del Plata, Bs. As. Publicado en Medicina, Bs As. Vol 78 Supl III-2018. ROLE OF SEX CHROMOSOME COMPLEMENT AND THE ORGANIZATIONAL GONADAL HORMONAL EFFECTS IN THE VASOPRESSINERGIC PRESSOR AND ANTIDIURETIC SEXUAL DIMORPHIC RESPONSESGonzalez, Lihue; Godino, Andrea; Vivas, Laura and Caeiro, Ximena.INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina.This study aimed to explore the role of the sex chromosome complement (SCC:XX/XY) and/or the organizational hormonal effects of gonadal steroids in the sexually dimorphic response to the antidiuretic desmopressin administration (vasopressin V2 receptor agonist) on urinary osmolarity and in the pressor response induced by systemic vasopressin infusion. To carry out the aforementioned experiments we used gonadectomized male (XX and XY) and female (XX and XY) mice of the "four core genotypes" model, in which the effect of gonadal sex and sex chromosome complement (SCC) is dissociated, allowing comparisons of sexually dimorphic traits among XX and XY females, as well as in XX and XY males. Mice aged 60-65 days old were gonadectomized and forty two days later were subcutaneously injected with vehicle solution or desmopressin (1 mg/kg). During the following four hour period mice had no access to water or food and immediately after urine samples were obtained for subsequent determination of osmolarity. Desmopressin infusion showed a significant effect of treatment and the interaction with sex factors {F (1,35) = 5.0650, p = 0.03080}. Desmopresine-male mice showed irrespectively of the SCC (XX-male and XY-male mice) a significant increase in urinary osmolarity when compared to desmopresine-females (both XX-females and XY-females). Furthermore, the analysis of blood pressure changes in response to a 30 minute vasopressin infusion (0,2 UI/ml, infusion volume 100µl) revealed a SCC modulatory effect; regardless of sex (male or female); XX-SCC mice showed a greater increase in blood pressure when compared to XY-SCC mice (XY-male and XY-female). This evidence may indicate that in the absence of the activating hormonal effect, the organizational hormonal factor would define the sexually dimorphic urinary osmotic phenotype, while sex differences in the pressor response to vasopressin infusion may be driven by the sex chromosomal complement factor. Support: ANPCyT, CONICET and Roemmers Foundation.