In vivo phosphorus-31 NMR spectroscopy of abnormal myocardial high-energy phosphate metabolism during cardiac stress in hypertensive-hypertrophied non-human primates

D. Douglas Miller, Richard A. Walsh

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

To study the functional and metabolic correlates of left ventricular hypertrophy [LVH] in non-human primates, 7 hypertensive baboons [papio anubis] with 4.6 ± 0.1 years of hypertension produced by a two-kidney one-clip model, and echocardiographically documented concentric LVH underwent serial phosphorus-31 [P-31] NMR Spectroscopy studies at rest and during inotropic cardiac stress produced by dobutamine infusion [5 μg/kg/minute]. Responses in LVH baboons were compared to those in 5 normotensive, sex and weight-matched control animals. The ratio of P-31 NMR-S derived inorganic phosphates [Pi] to phosphocreatine [PCr] was significantly greater at rest in LVH baboons [0.53 ± 0.06 versus controls = 0.41 ± 0.17; P<0.05]. With dobutamine drug stress, the Pi/PCr ratio rose significantly in LVH baboons [0.77 ± 0.15 versus 0.56 ± 0.16; P<0.05 at 15 minutes]. Despite hemodynamic recovery, the 5 minute post-dobutamine Pi/PCr ratio remained elevated compared to baseline in LVH baboons only [0.78 ± 0.16 versus 0.53 ± 0.06; P<0.05]. In pre-instrumented baboons [n=5], the 'transfer function' of cardiac work [heart rate × LV end-systolic pressure × + dp/dt max] versus Pi/PCr ratio was abnormally shifted rightward and downward [r=0.80] with LVH as compared to the linearly increasing response in controls. We conclude that in vivo P-31 NMR Spectroscopy studies during dobutamine stress demonstrate reduced PCr stores, delayed metabolic recovery following cessation of inotropic stress, and an abnormal rightward shift in the 'transfer function' in LVH baboons.

Original languageEnglish (US)
Pages (from-to)57-70
Number of pages14
JournalThe International Journal of Cardiac Imaging
Volume6
Issue number1
DOIs
StatePublished - Mar 1 1990
Externally publishedYes

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Keywords

  • cardiac work
  • dobutamine
  • left ventricular hypertrophy
  • oxidative metabolism
  • phosphorus-31 NMR spectroscopy

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine

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