Abstract

SALAZAR-RODRIGUEZ, M et al. ¿Participa la Histamina Mastocitaria en el reflejo periférico que modula la actividad simpática en la Rata?. AVFT [online]. 2002, vol.21, n.1, pp.53-57. ISSN 0798-0264.

ABSTRACT Earlier studies have shown the existence of a novel peripheral reflex, which down regulates sympathetic activity in the rat vas deferens. A similar inhibitory modulation was found in the dog heart. It appears that, as a rule, the sympathetic discharge interacts with histamine-containing neurons in the periphery. Neuronal histamine seems to be inhibitorily modulating noradrenaline release from sympathetic nerve terminals, thus damping down sympathetic activity and arterial pressure. Along these lines, enhancement of sympathetic activity is accompanied by an increase of L- histidine decarboxilase activity, and inhibition of neuronal histamine biosynthesis causes facilitation of sympathetic activity and arterial hypertension. All the evidence suggests that histamine is reflexly released when sympathetic activity is enhanced. Within this context, we studied the possible participation of mast cell histamine in the peripheral reflex of sympathetic autoregulation. The effects of chronic mast cell degranulation with 48/80, 0.75 mg/Kg i.p. daily for 12 days, on cardiovascular parameters were studied. Mean arterial pressure and heart rate did not change during the course or at the end of treatment with 48/80, which suggests that mast cell histamine is not involved in the functional regulation of sympathetic activity and arterial pressure.

Keywords : Neuronal and mast cell histamine; Peripheral reflex; Sympathetic activity.