Left ventricular remodeling with exercise in hypertension

Am J Physiol Heart Circ Physiol. 2009 Oct;297(4):H1361-8. doi: 10.1152/ajpheart.01253.2008. Epub 2009 Aug 7.

Abstract

We investigated how exercise training superimposed on chronic hypertension impacted left ventricular remodeling. Cardiomyocyte hypertrophy, apoptosis, and proliferation in hearts from female spontaneously hypertensive rats (SHRs) were examined. Four-month-old SHR animals were placed into a sedentary group (SHR-SED; n = 18) or a treadmill running group (SHR-TRD, 20 m/min, 1 h/day, 5 days/wk, 12 wk; n = 18). Age-matched, sedentary Wistar Kyoto (WKY) rats were controls (n = 18). Heart weight was greater in SHR-TRD vs. both WKY (P < 0.01) and SHR-SED (P < 0.05). Morphometric-derived left ventricular anterior, posterior, and septal wall thickness were increased in SHR-SED relative to WKY and augmented in SHR-TRD. Cardiomyocyte surface area, length, and width were increased in SHR-SED relative to WKY and further increased in SHR-TRD. Calcineurin abundance was increased in SHR-SED vs. WKY (P < 0.001) and attenuated in SHR-TRD relative to SHR-SED (P < 0.05). Protein abundance and mRNA of Akt was not different among groups. The rate of apoptosis was increased in SHR-SED relative to WKY and mitigated in SHR-TRD. The abundance of Ki-67(+) cells across groups was not statistically different across groups. The abundance of cardiac progenitor cells (c-Kit(+) cells) was increased in SHR-TRD relative to WKY. These data suggest that exercise training superimposed on hypertension augmented cardiomyocyte hypertrophy, despite attenuating calcineurin abundance. Exercise training also mitigated apoptosis in hypertension and showed a tendency to enhance the abundance of cardiac progenitor cells, resulting in a more favorable cardiomyocyte number in the exercise-trained hypertensive heart.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Calcineurin / metabolism
  • Cardiomegaly / etiology*
  • Cardiomegaly / pathology
  • Cardiomegaly / physiopathology
  • Cell Proliferation
  • Cell Size
  • Chronic Disease
  • Disease Models, Animal
  • Female
  • Hypertension / complications
  • Hypertension / metabolism
  • Hypertension / pathology
  • Hypertension / physiopathology*
  • In Situ Nick-End Labeling
  • Ki-67 Antigen / metabolism
  • Myocytes, Cardiac / metabolism
  • Myocytes, Cardiac / pathology
  • Physical Exertion*
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-kit / metabolism
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Inbred SHR
  • Rats, Inbred WKY
  • Stem Cells / metabolism
  • Stem Cells / pathology
  • Ventricular Function, Left*
  • Ventricular Remodeling*

Substances

  • Ki-67 Antigen
  • RNA, Messenger
  • Proto-Oncogene Proteins c-kit
  • Proto-Oncogene Proteins c-akt
  • Calcineurin