Changes of certain cardio-vascular parameters and the sympathetic nervous activity upon afferent vagal stimulation in cats.
Afferent stimulation of the cervical vagus in cats for 5 s upon bilateral vagotomy reduces systemic blood pressure by 15--50 percent. The maximum of this depressor reaction occurs 10--15 s after the beginning of the stimulation, its latency being 2--3 s. The decrease in the blood pressure is preceded by inhibition of the electrical activity of some preganglionic (n. splanchnicus) and postganglionic (n. cardiacus and n. renalis) sympathetic nerves with 100--200 ms latency. During the maximum pressure decrease activity appears in the above-mentioned nerves, afterwards the pressure begins to rise until its normalization. In addition to the decrease in systemic blood pressure changes are also observed in other cardio-vascular parameters, namely, decrease in the pressure in the left ventricle, decrease in the contractile force of the heart (dp/dt max) and of the heart rate.
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001338:Autonomic Fibers, Postganglionic / Q000502:physiology; D001339:Autonomic Fibers, Preganglionic / Q000502:physiology; D001794:Blood Pressure; D002415:Cats; D005260:Female; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D008297:Male; D009200:Myocardial Contraction; D011312:Pressure; D013564:Sympathetic Nervous System / Q000502:physiology*; D014630:Vagus Nerve / Q000502:physiology*