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[Mechanisms of the development of cardiogenic vagosympathetic reflexes]
Abstract:
Mechanisms of development of cardiogenic vagosympathetic depressor reflexes during adrenergic heart stimulation and local immune and ischemic damages of the left ventricle were studied in anesthetized dogs and cats by recording afferent and efferent impulsation from cardiac nerves as well as cardiodynamic indices. Impulse activity in cardiac nerves showed reciprocal changes: an increase in frequency of afferent impulsation in vagal nerves and inhibition of efferent impulsation in sympathetic nerves. The data obtained suggest that stimulation of heart mechanoreceptors due to the increase of myocardial contractility and asynergy of the left ventricle, is a triggering mechanism for reflex inhibition of sympathetic impulsation and depressor reflex.
Insights
Stimulating heart nerves or causing damage triggers vagosympathetic depressor reflexes. Increased vagal nerve activity and decreased sympathetic nerve activity result from heart mechanoreceptor stimulation, leading to blood pressure reduction.
Area of Science:
- Cardiovascular physiology
- Autonomic nervous system regulation
- Cardiac reflexes
Context:
- Understanding cardiogenic reflexes is crucial for managing cardiovascular conditions.
- Investigating the interplay between cardiac nerves and autonomic responses provides insights into heart function.
Purpose:
- To elucidate the mechanisms of vagosympathetic depressor reflexes.
- To examine reflex responses during adrenergic heart stimulation and left ventricular damage.
Summary:
- Studied vagosympathetic depressor reflexes in dogs and cats using electrophysiological and hemodynamic recordings.
- Observed reciprocal changes in cardiac nerve activity: increased vagal afferent and decreased sympathetic efferent impulsation.
- Identified heart mechanoreceptor stimulation, due to increased contractility and left ventricular asynergy, as the trigger for these reflexes.
Impact:
- Reveals the triggering mechanisms of depressor reflexes originating from the heart.
- Contributes to the understanding of autonomic control of the cardiovascular system.
- Provides a basis for exploring therapeutic interventions targeting cardiac reflexes.