INIMEC - CONICET   05467
INSTITUTO DE INVESTIGACION MEDICA MERCEDES Y MARTIN FERREYRA
Unidad Ejecutora - UE
artículos
Título:
EFFECT OF SEX CHROMOSOME COMPLEMENT ON SODIUM APPETITE AND FOS IMMUNOREACTIVITY INDUCED BY SODIUM DEPLETION
Autor/es:
DADAM FLORENCIA; CAEIRO XE; CISTERNAS CD; MACCHIONE AF; CAMBIASSO MJ; VIVAS L
Revista:
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY, INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
Editorial:
AMER PHYSIOLOGICAL SOC
Referencias:
Lugar: Bethesda; Año: 2014 vol. 306 p. 175 - 184
ISSN:
0363-6119
Resumen:
Previous studies indicate a sex chromosome complement (SCC) effect on the Angiotensin II-sexually dimorphic hypertensive and bradycardic baroreflex responses. We sought to evaluate whether SCC may differentially modulate sexually dimorphic induced sodium appetite and specific brain activity due to physiological stimulation of the rennin angiotensin system. For this purpose, we used the "four core genotypes" mouse 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. Gonadectomized mice were sodium depleted by furosemide (50 mg/kg) and low sodium diet treatment; control groups were administered the vehicle and maintained on normal sodium diet. Twenty-one hours later, the mice were divided into two groups: one was submitted to the water/NaCl 2% choice intake test, while the other was perfused and their brains subjected to the Fosimmunoreactivity (Fos-ir) procedure. Sodium depletion, regardless of genetic sex (XX or XY), induced a significantly lower sodium and water intake in females than in males, confirming the existence in mice of sexual dimorphism in sodium appetite and the organizational involvement of gonadal steroids. Moreover, our results demonstrate a SCC effect on induced brain Fos-ir, showing increased brain activity in XX-SCC mice at the paraventricular nucleus, nucleus of the solitary tract and lateral parabrachial nucleus, as well as an XX-SCC augmented effect on sodium-depletion induced brain activity at two circumventricular organs, the subfornical organ and area postrema, nuclei closely involved in fluid and blood pressure homeostasis.