|
|
||||||||
University of Pittsburgh School of Nursing, Pittsburgh, Pennsylvania 15261
Pregnancy is associated with blunted reflex responses to
cardiac and arterial baroreceptor stimulation. We tested the hypothesis that arterial baroreceptor afferent discharge is attenuated in response
to a pressure stimulus in pregnant rats. Multifiber aortic depressor
nerve activity (ADNA), mean arterial pressure (MAP), and heart rate
were measured in anesthetized (pentobarbital sodium, 35 mg/kg ip)
late-pregnant and virgin rats in response to increases [phenylephrine (PE), 1.5-24
µg · kg
1 · min
1
and 1-16 µg/kg] and decreases [sodium nitroprusside
(SNP), 5-80 µg · kg
1 · min
1
and 0.05-16 µg/kg] in MAP. Resting MAP was lower in
pregnant rats, but changes in MAP were similar to those in virgin rats during both PE and SNP administration. ADNA was significantly attenuated in pregnant animals during both PE and SNP infusions (P < 0.05) due to a more rapid adaptation to the pressure
stimulus. Bolus drug administration evoked similar changes in MAP and
ADNA in both groups; however, the maximum decrease in ADNA was achieved at the lowest dose of SNP in pregnant rats. Thus baroreceptor afferent
discharge is attenuated in pregnant rats, and this involves a more
rapid adaptation to a pressure stimulus.
baroreflex; aortic depressor nerve; phenylephrine; nitroprusside
This article has been cited by other articles:
![]() |
L. Kvochina, E. M. Hasser, and C. M. Heesch Pregnancy increases baroreflex-independent GABAergic inhibition of the RVLM in rats Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2007; 293(6): R2295 - R2305. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Granger Maternal and fetal adaptations during pregnancy: lessons in regulatory and integrative physiology Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2002; 283(6): R1289 - R1292. [Full Text] [PDF] |
||||
![]() |
H. M. Stauss Baroreceptor reflex function Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2002; 283(2): R284 - R286. [Full Text] [PDF] |
||||
![]() |
V. L. Brooks, K. A. Clow, and K. P. O'Hagan Pregnancy and acute baroreflex resetting in conscious rabbits Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2002; 283(2): R429 - R440. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. D. Laiprasert, R. L. Hamlin, and C. M. Heesch Afferent baroreceptor discharge in pregnant rats Am J Physiol Heart Circ Physiol, December 1, 2001; 281(6): H2456 - H2462. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |