| Autor: |
Hougen, Thomas J, Vasu, M Andre, Chipman, Carl, Woodford, Edward J, Marx, Gerald R |
| Zdroj: |
Pediatric Research; April 1984, Vol. 18 Issue: 1, Number 1 Supplement 4 p123A-123A, 1p |
| Abstrakt: |
The physiological and myocardial effects of digoxin in infants and children are debated and uncertain. In order to examine the response of the myocardial NaK-pump to chronic digoxin administration active transport of the K+analog Rb+was measured in vitro in serial right atrial biopsies in young lambs. Nine lambs (mean age 7d) were lightly sedated, instrumented, and ECG, aortic pressure, LV pressure and LVdP/dt were recorded. General anesthesia was then induced and a right atrial biopsy was obtained for Rb+active transport determination. This procedure was repeated 34d (mean) later after either no treatment (controls, n=4) or digoxin (n=5). Digoxin was given I.M. to maintain a plasma concentration of 1.3 ng/ml (mean) with no toxicity. The changes in hemodynamics between initial and final study were similar in both groups. No significant difference was observed in controls between initial and final Rb+active transport values (0.381 ± 0.015 (± SEM) nmol Rb+/mg wet wt/30 min vs 0.364 ± 0.023, paired t). In contrast, digoxin inhibited Rb+active transport when compared to initial values (0.349 ± 0.014 vs 0.246 ± 0.033, P < 0.05). Under these conditions the NaK-pump was inhibited indicating that chronic digoxin administration in therapeutic concentrations does have a myocardial effect in the developing mammalian heart. |
| Databáze: |
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