You are in the accessibility menu

Please use this identifier to cite or link to this item:
Cardiac baroreflex is already blunted in eight weeks old spontaneously hypertensive rats
  • School of Medicine of ABC
  • Universidade de São Paulo (USP)
  • Universidade Estadual Paulista (UNESP)
Background. The literature did not evidence yet with which age spontaneously hypertensive rats (SHR) start to present baroreflex reduction. We endeavored to evaluate the baroreflex function in eight-week-old SHR. Methods. Male Wistar Kyoto (WKY) normotensive rats and SHR aged eight weeks were studied. Baroreflex was calculated as the variation of heart rate (HR) divided by the mean arterial pressure (MAP) variation (HR/MAP) tested with a depressor dose of sodium nitroprusside (SNP, 50 g/kg) and with a pressor dose of phenylephrine (PHE, 8 g/kg) in the right femoral venous approach through an inserted cannula in the animals. Significant differences for p < 0.05. Results. Baseline MAP (p < 0.0001) and HR (p = 0.0028) was higher in SHR. Bradycardic peak was attenuated in SHR (p < 0.0001), baroreflex gain tested with PHE was also reduced in the SHR group (p = 0.0012). PHE-induced increase in MAP was increased in WKY compared to SHR (p = 0.039). Bradycardic reflex responses to intravenous PHE was decreased in SHR (p < 0.0001). Conclusion. Eight weeks old SHR already presents impairment of the parasympathetic component of baroreflex. © 2010 Cisternas et al; licensee BioMed Central Ltd.
Issue Date: 
International Archives of Medicine, v. 3, n. 1, 2010.
  • nitroprusside sodium
  • phenylephrine
  • aged
  • animal experiment
  • bradycardia
  • cannulation
  • cardiac baroreflex
  • clinical evaluation
  • controlled study
  • femoral vein
  • heart rate
  • male
  • mean arterial pressure
  • nonhuman
  • pressoreceptor reflex
  • rat
  • spontaneously hypertensive rat
  • Wistar Kyoto rat
Access Rights: 
Acesso aberto
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.