Pacing-induced cardiac failure of hypertrophic hearts reduces the functional and metabolic effects of isoproterenol

M. Huang, R. Leone, H. R. Weiss, J. Tse, P. M. Scholz

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

The study was designed to test the hypothesis that the transition to pacing-induced cardiac failure of hypertrophic hearts would demonstrate a reduction in the functional and metabolic response to β-adrenergic stimulation related to reduced myocardial cAMP. An infusion of 0.1 μg/kg/min of isoproterenol (ISO) into the left anterior descending (LAD) coronary artery was performed in 5 control, 5 left ventricular hypertrophy (LVH), and 5 LVH pacing-induced failure dogs. Regional work was calculated as the integrated product of force and segment shortening. Regional myocardial O2 consumption was calculated from LAD flow and O2 extraction measurements. Intracellular cAMP was determined by radio-immunoassay. ISO significantly increased local work (1923 ± 665 vs. 2656 ± 715, 1185 ± 286 vs. 1906 ± 562 g*mm/min), force (11.1 ± 3.0 vs. 16.9 ± 5.9, 8.6 ± 3.3 vs. 13.7 ± 5.1 g) and myocardial O2 consumption (7.3 ± 2.0 vs. 10.0 ± 1.5, 8.2 ± 1.6 vs. 11.6 ± 2.6 ml O2/min/100 g) in control and LVH dogs but not in failure dogs (835 ± 106 vs. 849 ± 216, 12.2 ± 2.5 vs. 11.0 ± 4.1, 4.4 ± 1.5 vs. 5.5 ± 1.8). ISO also significantly increased cAMP in control and LVH dogs (474 ± 67 vs. 600 ± 91, 473 ± 34 vs. 619 ± 53 pmol/g). In failure dogs, cAMP was significantly lower (245 ± 43 vs. 314 ± 40) than in control and LVH dogs and there was no significant increase in cAMP in response to ISO. We conclude that the myocardial functional, O2 consumption and cAMP responses to isoproterenol are diminished in the transition from hypertrophy to cardiac failure.

Original languageEnglish (US)
Pages (from-to)A977
JournalFASEB Journal
Volume12
Issue number5
StatePublished - Mar 20 1998

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Biochemistry
  • Molecular Biology
  • Genetics

Fingerprint Dive into the research topics of 'Pacing-induced cardiac failure of hypertrophic hearts reduces the functional and metabolic effects of isoproterenol'. Together they form a unique fingerprint.

Cite this