TY - JOUR
T1 - Is there a central nervous system component to acute baroreflex resetting in rats?
AU - Heesch, C. M.
AU - Barron, K. W.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 1992
Y1 - 1992
N2 - This study was designed to evaluate a possible central nervous system (CNS) component to acute baroreflex resetting. In nine arterial baroreceptor- denervated, chloralose-urethan-anesthetized rats, a control (C) aortic nerve stimulation curve (3-5 V, 1 ms, 0-64 Hz) was obtained. Next, a constant 'baroreceptor' input was delivered to the CNS (left aortic nerve stimulation, 10 min, 10.2 ± 1.5 Hz). Within the first 13 s of aortic nerve stimulation, maximum inhibition of lumbar sympathetic nerve activity (LSNA) was 60 ± 7.8% of baseline and at 1 min it increased to 68 ± 5.6% of baseline. At the end of the 10-min aortic nerve stimulation, LSNA was not different from the response at 1 min (68 ± 5.6% = 74 ± 4.1%). Immediately after the constant stimulation (within 30 s), a test or reset (RS) curve was obtained (0-64 Hz). A recovery (RC) curve was obtained 10-20 min later. The slope of the linear portion of the curve and the stimulation frequency that produced 50% maximum inhibition (ES50) were compared among the three baroreflex curves (C, RS, RC,) and no significant differences were found. Thus, although a CNS component to baroreflex adaptation was evident during the first minute of aortic nerve stimulation, a longer term acute resetting of the baroreflex curve did not occur.
AB - This study was designed to evaluate a possible central nervous system (CNS) component to acute baroreflex resetting. In nine arterial baroreceptor- denervated, chloralose-urethan-anesthetized rats, a control (C) aortic nerve stimulation curve (3-5 V, 1 ms, 0-64 Hz) was obtained. Next, a constant 'baroreceptor' input was delivered to the CNS (left aortic nerve stimulation, 10 min, 10.2 ± 1.5 Hz). Within the first 13 s of aortic nerve stimulation, maximum inhibition of lumbar sympathetic nerve activity (LSNA) was 60 ± 7.8% of baseline and at 1 min it increased to 68 ± 5.6% of baseline. At the end of the 10-min aortic nerve stimulation, LSNA was not different from the response at 1 min (68 ± 5.6% = 74 ± 4.1%). Immediately after the constant stimulation (within 30 s), a test or reset (RS) curve was obtained (0-64 Hz). A recovery (RC) curve was obtained 10-20 min later. The slope of the linear portion of the curve and the stimulation frequency that produced 50% maximum inhibition (ES50) were compared among the three baroreflex curves (C, RS, RC,) and no significant differences were found. Thus, although a CNS component to baroreflex adaptation was evident during the first minute of aortic nerve stimulation, a longer term acute resetting of the baroreflex curve did not occur.
KW - aortic nerve stimulation
KW - baroreceptor reflex
KW - lumbar sympathetic nerve activity
UR - http://www.scopus.com/inward/record.url?scp=0026559665&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.1992.262.2.h503
DO - 10.1152/ajpheart.1992.262.2.h503
M3 - Article
C2 - 1539709
AN - SCOPUS:0026559665
SN - 0363-6135
VL - 262
SP - H503-H510
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 2 31-2
ER -