Adrenergic and imidazoline mechanisms of arterial baroreceptor reflex in the short and long-term regulation of blood pressure

Abstract

Objective. The purpose of this work was to study how selective activation of сentral adrenergic and imidazoline receptors influence functional state of the blood baroreceptor reflex (BR) in the short and long-term regulation of blood pressure (BP) at rest and under emotional stress. Design and methods. Experiments were conducted on awake Wistar rats. Clonidine (1 and 10 mg/kg) was used for adrenergic receptors activation, moxonidine (10 and 100 mg/kg) was used for imidazoline receptor activation. Emotional stress was caused by sound signal (a ring). Results. Studies demonstrated that the activation of central imidazoline receptors does not change BP level, while alpha 2‑adrenergic systems play a major role in the central regulation of vascular tone and cardiac function. Both imidazoline and alpha 2‑adrenergic systems participate in functioning of baroreceptor reflex. Conclusions. Emotional stress-associated imidazoline receptor activation restores initial BR and reduces BP elevation in rats. Alpha 2‑adrenergic systems do not have a significant impact on cardiovascular manifestations of emotional tension.