Afferent and efferent nerve activity of arterial baroreceptor reflex under nonpulsatile systemic circulation.
We studied the changes in arterial baroreceptor reflex (ABR) afferent activity and efferent activity induced by nonpulsatile systemic circulation (NC) during total left heart bypass (TLHB) in rabbits. To evaluate the influence of the circuit priming fluid and exposure to NC, we directly measured aortic depressor nerve activity (ADNA) (n = 5) and renal sympathetic nerve activity (RSNA) (n = 5) before the start of partial left heart bypass (PLHB) (Before), after PHLB (After), and 5 min after the start of TLHB (During THLB) while maintaining the mean aortic pressure. The circuit priming fluid did not affect the ABR. ADNA exhibited periodic discharge at Before and After, but at During THLB, this periodic discharge transformed into a continuous discharge, and ADNA increased significantly. However, there were no significant differences in RSNA. Our results suggested that in the acute phase under NC, the ABR differed from that under natural circulation.
Shomura
Y
Y
Department of Thoracic and Cardiovascular Surgery, Mie University School of Medicine, Japan.
Tanaka
K
K
Takabayashi
S
S
Hioki
I
I
Tenpaku
H
H
Maze
Y
Y
Shimono
T
T
Shimpo
H
H
Yada
I
I
D000322:Adrenergic Agonists / Q000097:blood; D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001011:Aorta / Q000294:innervation; D017704:Baroreflex / Q000502:physiology*; D001775:Blood Circulation / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D004525:Efferent Pathways / Q000502:physiology; D004837:Epinephrine / Q000097:blood; D018611:Heart Bypass, Left / Q000295:instrumentation / Q000379:methods; D006339:Heart Rate / Q000502:physiology; D007668:Kidney / Q000294:innervation; D009638:Norepinephrine / Q000097:blood; D011311:Pressoreceptors / Q000502:physiology*; D011817:Rabbits; D013564:Sympathetic Nervous System / Q000502:physiology; D013566:Sympathomimetics / Q000097:blood; D009435:Synaptic Transmission / Q000502:physiology; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology; D017725:Ventricular Pressure / Q000502:physiology
D000322:Adrenergic Agonists; D013566:Sympathomimetics; D009638:Norepinephrine; D004837:Epinephrine