Myocardial Carbohydrate, Ketone, and Fatty Acid Uptake in Conscious Lambs with Aortopulmonary Shunts1
| Autor: | M Dalinghaus, J. H. Koers, A. M. Gerding, F A J Muskiet, J. J. Meuzelaar, Jrg Kuipers, J. W. C. Gratama |
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| Rok vydání: | 1992 |
| Předmět: |
medicine.medical_specialty
Right-to-left shunt Stroke volume Metabolism Biology Pyruvate dehydrogenase complex medicine.disease chemistry.chemical_compound Endocrinology chemistry medicine.artery Lactate dehydrogenase Internal medicine Heart failure Pediatrics Perinatology and Child Health medicine Catecholamine Shunt (electrical) medicine.drug |
| Zdroj: | Pediatric Research. 32:27-32 |
| ISSN: | 1530-0447 0031-3998 |
| Popis: | A left to right shunt increases myocardial work and is often accompanied by increased catecholamine levels. Because both increased myocardial work and increased catecholamine levels may induce increased fatty acid utilization, which could increase resting myocardial oxygen consumption and therefore unfavorably affect coronary reserve, we studied myocardial uptake of glucose, pyruvate, lactate, β-OH-butyrate, acetoacetate, FFA, and triglycerides in 12 7-wk-old lambs with aortopulmonary left to right shunts (58 ± 2% of left ventricular output, mean ± SEM) and in 10 control lambs 2 wk after surgery. Despite the shunt, systemic blood flow in the shunt lambs was maintained at the same level as in the control lambs. This was accomplished by an increased heart rate and stroke volume. Furthermore, the shunt was accompanied by an increased myocardial oxygen consumption in the shunt lambs (834 ± 70 versus 528 ± 43 μmol O2·min−1·100 g−1; p < 0.05). There were no significant differences in arterial substrate concentrations between the two groups. The same was true for arteriovenous differences across the myocardium, with the exception of lactate, which was substantially higher in shunt than in control lambs (72 ± 25 versus 18 ± 23 μmol/L; p < 0.05). As a consequence, myocardial lactate uptake in the shunt lambs was increased 15-fold (18 ± 6 versus 1 ± 2 μmol·min−1·100 g−1; p < 0.02), whereas uptake of the other substrates merely paralleled the increased myocardial blood flow. Our data demonstrate that myocardial substrate uptake is not substantially different between shunt and control lambs, with the exception of lactate, of which the extraction is 10-fold higher than in control lambs. We speculate that the increased myocardial lactate utilization may reflect an increase of lactate and pyruvate dehydrogenase activities. |
| Databáze: | OpenAIRE |
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