External detection and visualization of myocardial ischemia with /sup 11/C-substrates in vitro and in vivo

Journal Article · Thu Jul 01 04:00:00 EDT 1976 · Circ. Res.; (United States)

DOI:https://doi.org/10.1161/01.RES.39.1.24· OSTI ID:7215395

Weiss, E S; Hoffman, E J; Phelps, M E; Welch, M J; Henry, P D; Ter-Pogossian, M M; Sobel, B E

To characterize externally detectable changes in myocardial metabolism of free fatty acids (FFA) and glucose associated with ischemia, isovolumically beating rabbit hearts were perfused under conditions of selected flows with cyclotron-produced, short-lived (t/sub /sup 1///sub 2/ = 20.4 minutes), /sup 11/C-labeled isotopes of glucose and FFA. Tension-time index decreased 83% and lactate production increased from 0.5 +- 1.9 (SE) to 5.3 +- 2.1 ..mu..mol/min per g of dry weight reflecting myocardial ischemia after flow was reduced from 20 to 5 ml/min. After 30 minutes of low flow the myocardial accumulation of /sup 11/C-octanoate, expressed as the extraction fraction, declined from 56 +- 15% to 30 +- 3%, reflecting metabolic suppression of FFA extraction during low flow. Effects attributable exclusively to prolonged residence time were excluded. Similar results were obtained with /sup 11/C-palmitate. The myocardial avidity for /sup 11/C-palmitate was demonstrable by rectilinear whole body scanning in dogs given 5 mCi of the agent intravenously. Diminished /sup 11/C-palmitate uptake in zones of myocardium rendered ischemic for 20 minutes prior to reflow in intact dogs was delineated by electrocardiographically gated positron-emission transaxial computer reconstruction tomography. Thus, diminished /sup 11/C-FFA extraction, externally detectable, accompanies decreased perfusion in isolated perfused hearts, and decreased /sup 11/C-FFA uptake reflecting myocardial ischemia in vivo can be evaluated noninvasively by positron-emission transaxial tomography.

• Research Organization: Washington Univ., St. Louis
• OSTI ID: 7215395
• Journal Information: Circ. Res.; (United States), Journal Name: Circ. Res.; (United States) Vol. 39:1; ISSN CIRUA
• Country of Publication: United States
• Language: English

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550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALDEHYDES
ANEMIAS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CARBON 11
CARBON ISOTOPES
CARBOXYLIC ACIDS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
COUNTING TECHNIQUES
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
EVEN-ODD NUCLEI
GLUCOSE
HEART
HEMIC DISEASES
HEXOSES
IN VITRO
IN VIVO
ISCHEMIA
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
METABOLISM
MINUTES LIVING RADIOISOTOPES
MONOSACCHARIDES
MUSCLES
MYOCARDIUM
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPE SCANNING
RADIOISOTOPES
SACCHARIDES
SCINTISCANNING
SYMPTOMS
TOMOGRAPHY