title: Baroreflex sensitivity impairment is associated with cardiac diastolic dysfunction in rats.
abstract: BACKGROUND
  Studies have shown that the autonomic dysfunction accompanied by impaired baroreflex sensitivity was associated with higher mortality. However, the influence of decreased baroreflex sensitivity on cardiac function, especially in diastolic function, is not well understood. This study evaluated the morphofunctional changes associated with baroreflex impairment induced by chronic sinoaortic denervation (SAD).
  
  
  RESULTS
  Animals were divided into sinoaortic denervation (SAD) and control (C) groups. Baroreflex sensitivity was evaluated by tachycardic and bradycardic responses, induced by vasoactive drugs. Cardiac function was studied by echocardiography and by left ventricle (LV) catheterization. LV collagen content and the expression of regulatory proteins involved in intracellular Ca(2+) homeostasis were quantified. Results showed higher LV mass in SAD versus C animals. Furthermore, an increase in deceleration time of E-wave in the SAD versus the C group (2.14 ± 0.07 ms vs 1.78 ± 0.03 ms) was observed. LV end-diastolic pressure was increased and the minimum dP/dt was decreased in the SAD versus the C group (12 ± 1.5 mm Hg vs 5.3 ± 0.2 mm Hg and 7,422 ± 201 vs 4,999 ± 345 mm Hg/s, respectively). SERCA/NCX ratio was lower in SAD than in control rats. The same was verified in SERCA/PLB ratio.
  
  
  CONCLUSIONS
  The results suggest that baroreflex dysfunction is associated with cardiac diastolic dysfunction independently of the presence of other risk factors.
authors.affiliation: Hypertension Unit, Heart Institute, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Mostarda
authors.forename: Ivana Cinthya
authors.initials: IC
authors.lastname: Moraes-Silva
authors.forename: Edson Dias
authors.initials: ED
authors.lastname: Moreira
authors.forename: Alessandra
authors.initials: A
authors.lastname: Medeiros
authors.forename: Aline Cristina
authors.initials: AC
authors.lastname: Piratello
authors.forename: Fernanda Marciano
authors.initials: FM
authors.lastname: Consolim-Colombo
authors.forename: Elia Garcia
authors.initials: EG
authors.lastname: Caldini
authors.forename: Patricia Chakur
authors.initials: PC
authors.lastname: Brum
authors.forename: Eduardo Moacyr
authors.initials: EM
authors.lastname: Krieger
authors.forename: Maria Claudia
authors.initials: MC
authors.lastname: Irigoyen
mesh_terms: D000818:Animals; D017704:Baroreflex / Q000502:physiology*; D003714:Denervation; D004195:Disease Models, Animal; D054144:Heart Failure, Diastolic / Q000503:physiopathology*; D008297:Male; D011311:Pressoreceptors / Q000503:physiopathology* / Q000601:surgery; D051381:Rats; D017208:Rats, Wistar; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*