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Baroreflex influence on arterial pressure and heart rate in conscious mice
Author(s) -
Fazan Rubens,
Rodrigues Fernanda Luciano,
Oliveira Mauro,
Salgado Helio Cesar,
Dias da Silva Valdo Jose
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.609.3
Subject(s) - baroreceptor , baroreflex , mean arterial pressure , anesthesia , blood pressure , phenylephrine , medicine , heart rate , heart rate variability , femoral artery , sodium nitroprusside , nitric oxide
The goal of this study was to determine the baroreflex influence on arterial pressure and pulse intervals (PI) in conscious mice. Male C57BL mice were subjected to sinoaortic denervation (SAD, n=14) or sham surgery (n=17), and catheters were placed into the femoral artery and jugular vein. 24 h or 5 days after surgery arterial pressure was continuously recorded for 30 min in the conscious mice. Efficacy of SAD was determined at the end of pressure recording by i.v. administration of phenylephrine and sodium nitroprusside. The standard deviation of systolic arterial pressure (SAP) measurements and the square root of the mean squared differences of successive values of PI were used as measurements of SAP and PI variability, respectively. Baroreceptor denervated mice showed higher SAP at both 24 h (144±8 vs. 125±4 mmHg) and 5 days (152±3 vs. 135±3 mmHg) after SAD. Variability of SAP was also markedly increased in SAD mice as compared with sham‐operated controls (8.0±1.3 vs. 4.9±0.8 and 9.8±1.1 vs. 6.4±0.6 mmHg, 24 h and 5 days after SAD). PI was found similar among the groups studied (119±8 vs. 115±8 and 105±4 vs. 94±3 ms, 24 h and 5 days after SAD). Variability of PI was less in mice 24 h after SAD (0.90±0.06 ms) compared to that observed in mice subjected to sham surgery (1.28±0.11 ms). Interestingly PI variability did not differ in SAD vs. sham‐operated mice 5 days post surgery (1.87±0.27 and 1.82±0.19 ms) (Support: FAPESP, CNPq).