Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1983-8-11
pubmed:abstractText
The loop gain (G) of the carotid baroreceptor was determined using open- and closed-loop approach in anesthetized rabbits after aortic denervation and vagotomy. The open-loop relationship between the intrasinus pressure (ISP) and systemic arterial pressure (SAP) was nonlinear. The slope (delta SAP/delta ISP) or G was maximal (about 1.5) near the control arterial pressure and decreased toward the saturation pressures. We examined how this nonlinearity relates to the arterial pressure compensation following hemorrhage. Because the baroreflex attenuation of the posthemorrhagic hypotension depends on the SAP responses to an input perturbation, we first demonstrated that the open-loop responses in SAP to a specific delta ISP was not altered during various amounts of hemorrhage, despite different operating range for the responses. In the open-loop condition when ISP was fixed at the control level, hemorrhage of 10, 20, and 30 ml produced a SAP disturbance (D) of 23.3, 43.5, and 62.4 mmHg, respectively. The figures were minimized to 9.8, 19.8, and 34.4 mmHg (D'), respectively through the baroreflex compensation in the closed-loop condition. The calculated G (D/D' - 1) from the closed-loop data were 1.38, 1.20, and 0.82 for 10, 20, and 30 ml hemorrhage. For a given input signal (delta ISP = D'), the values of G were essentially the same as those obtained from the open-loop ISP-SAP curve. The G values decreased as the degree of hemorrhagic hypotension increased, being in agreement with the sigmoid characteristics of the nonlinear ISP-SAP curve.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
245
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H54-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Baroreflex open-loop gain and arterial pressure compensation in hemorrhagic hypotension.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't