Resumen

GUIA, A et al. Influencia de las Endotelinas y el Factor Natriurético Auricular en la respuesta cardiovascular al NaCl hipertónico administrado en la región anteroventral del tercer ventrículo de la rata. AVFT [online]. 2004, vol.23, n.1, pp.45-49. ISSN 0798-0264.

Third ventricle anteroventral area (AV3V) is sensitive to changes in NaCl concentration and able to modify blood pressure and renal function in response to NaCl concentration. Hypertonic NaCl microinjections in AV3V induce a sympathetic cardiovascular response which increases blood pressure and heart rate; these changes can be modulated by central administration of 5HT₂ and AT₁ receptor blockers, and also by peripheral administration of a and b adrenergic receptor antagonists. Influence of endothelin receptors (ETR) and atrial natriuretic factor (ANF) on sensitivity to NaCl has not been explored. Hypertonic 1,5 M NaCl (2 mL volume) microinjections in AV3V of normotensive anesthetized rats increased mean arterial blood pressure by 17,9 ± 2.2 mm Hg (p<0.01). ANF microinjections (5mg/2mL) in AV3V neither changed mean arterial blood pressure nor altered the hypertensive response to NaCl 1,5 M microinjection. Microinjection of PD 142893 into AV3V a non selective endothelin antagonist (3mg/2mL) did not modify basal blood pressure but reduced by 47,6% (p<0,01) the hypertensive response to 1,5 M NaCl injection. These results indicates a possible modulator effect of endothelin receptors in the NaCl centrally- evocated cardiovascular response to hypertonic NaCl injections in AV3V. Acute microinjection of ANF in this brain area seems not to be involved in the NaCl-evoked sympathetic cardiovascular response.

Palabras clave : Anteroventral area of third ventricle; Hypertonic NaCl; Sympathetic cardiovascular response; Blood pressure regulation.