2.50
Hdl Handle:
http://hdl.handle.net/10755/158637
Type:
Presentation
Title:
What Does the Brain Know About Blood Pressure During Pregnancy?
Abstract:
What Does the Brain Know About Blood Pressure During Pregnancy?
Conference Sponsor:Midwest Nursing Research Society
Conference Year:2003
Author:Hines, Tina
Contact Address:SON, 2220 Holmes St, Kansas City, MO, 64108, USA
Blood pressure falls significantly early in pregnancy, and this change is maintained until term. In the nonpregnant female, hypotension would be rapidly detected by baroreceptors, and that information would be transmitted to the brain, which would restore pressure to baseline. This doesn’t happen during gestation, implying that there is some alteration in baroreflex activity. Indeed, it has been shown that the baroreflex is blunted during pregnancy, and when hypertension of develops, as in preeclampsia, there is a further reduction in baroreflex sensitivity, rendering this neural reflex useless in restoring normal pressure. We have demonstrated that more rapid adaptation of baroreceptors to a short-term pressure stimulus may play a role in the reduction of baroreflex function in normal pregnant rats. The current study was designed to measure baroreceptor responses to pressure changes over time in pregnant compared with virgin rats. Anesthetized animals were instrumented with arterial and venous catheters, and arterial pressure and aortic depressor nerve activity (i.e. baroreceptor firing) were recorded in response to 30 minutes of sustained hypertension and 30 minutes of sustained hypotension. In response to hypertension, baroreceptor firing in pregnant rats showed periodic oscillations, but the mean change in discharge was not different from virgin rats. In contrast, sustained hypotension evoked significantly smaller decreases in baroreceptor firing in pregnant animals. Thus, over the course of gestation, the brain may not interpret sustained hypertension differently from the nonpregnant state, but incoming signals related to hypotension are attenuated during pregnancy in the rat. Since the pregnant female is hypotensive and must remain so until term, blunted information going to the brain about the decline in blood pressure could play a role in maintaining this important adaptation. Uncovering mechanisms for this gestational change in cardiovascular regulation could help to elucidate factors that further disturb baroreflex function in preeclampsia. AN: MN030383
Repository Posting Date:
26-Oct-2011
Date of Publication:
17-Oct-2011
Sponsors:
Midwest Nursing Research Society

Full metadata record

DC FieldValue Language
dc.typePresentationen_GB
dc.titleWhat Does the Brain Know About Blood Pressure During Pregnancy?en_GB
dc.identifier.urihttp://hdl.handle.net/10755/158637-
dc.description.abstract<table><tr><td colspan="2" class="item-title">What Does the Brain Know About Blood Pressure During Pregnancy? </td></tr><tr class="item-sponsor"><td class="label">Conference Sponsor:</td><td class="value">Midwest Nursing Research Society</td></tr><tr class="item-year"><td class="label">Conference Year:</td><td class="value">2003</td></tr><tr class="item-author"><td class="label">Author:</td><td class="value">Hines, Tina</td></tr><tr class="item-address"><td class="label">Contact Address:</td><td class="value">SON, 2220 Holmes St, Kansas City, MO, 64108, USA</td></tr><tr><td colspan="2" class="item-abstract">Blood pressure falls significantly early in pregnancy, and this change is maintained until term. In the nonpregnant female, hypotension would be rapidly detected by baroreceptors, and that information would be transmitted to the brain, which would restore pressure to baseline. This doesn&rsquo;t happen during gestation, implying that there is some alteration in baroreflex activity. Indeed, it has been shown that the baroreflex is blunted during pregnancy, and when hypertension of develops, as in preeclampsia, there is a further reduction in baroreflex sensitivity, rendering this neural reflex useless in restoring normal pressure. We have demonstrated that more rapid adaptation of baroreceptors to a short-term pressure stimulus may play a role in the reduction of baroreflex function in normal pregnant rats. The current study was designed to measure baroreceptor responses to pressure changes over time in pregnant compared with virgin rats. Anesthetized animals were instrumented with arterial and venous catheters, and arterial pressure and aortic depressor nerve activity (i.e. baroreceptor firing) were recorded in response to 30 minutes of sustained hypertension and 30 minutes of sustained hypotension. In response to hypertension, baroreceptor firing in pregnant rats showed periodic oscillations, but the mean change in discharge was not different from virgin rats. In contrast, sustained hypotension evoked significantly smaller decreases in baroreceptor firing in pregnant animals. Thus, over the course of gestation, the brain may not interpret sustained hypertension differently from the nonpregnant state, but incoming signals related to hypotension are attenuated during pregnancy in the rat. Since the pregnant female is hypotensive and must remain so until term, blunted information going to the brain about the decline in blood pressure could play a role in maintaining this important adaptation. Uncovering mechanisms for this gestational change in cardiovascular regulation could help to elucidate factors that further disturb baroreflex function in preeclampsia. AN: MN030383 </td></tr></table>en_GB
dc.date.available2011-10-26T21:15:02Z-
dc.date.issued2011-10-17en_GB
dc.date.accessioned2011-10-26T21:15:02Z-
dc.description.sponsorshipMidwest Nursing Research Societyen_GB
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