Summary
Male Sprague-Dawley rat (200–220 g) were employed, to study the effect of a calcium antagonistic drug on hypoxia-induced myocardial hypertrophy.
The hypoxic condition was obtained by exposure of animals to reduced barometric pressure in a hypobaric chamber. The rats, divided in groups, were exposed to acute or chronic intermittent hypoxia (0.42 atmospheres of air for 24 hrs or 0.42 atm for 12 hrs per day for 10 days, respectively). Verapamil (VRP) was given subcutaneously in a total dose of 200 mg/kg/b.w./rat. In hypoxic rats, the durg significantly reduced the values of dry heart weight calculated on the basis of its relationship to total body weight.
This phenomenon is probably due to: (1) reduced activation of the contractile system and a thereby resulting decrease in ATP breakdown as a result of blocking of Ca++ inflow into myocardial cells; (2) the effect of Verapamil on hypoxia-induced pulmonary hypertension and/or (3) a direct effect of the drug on the myocardial cell.
Zusammenfassung
An männlichen Sprague-Dawley-Ratten (200–220 g) wurden die Effekte einer Ca++-antagonistischen Substanz auf die hypoxiebedingte Hypertrophie des Myokards untersucht.
Die Tiere wurden in einer Unterdruckkammer einem reduzierten Luftdruck ausgesetzt. Die Ratten wurden zwei Gruppen aufgeteilt und unter akutem oder chronisch intermittierendem Sauerstoffmangel gehalten (0,42 Atmosphären für 24 Stunden bzw. 0,42 Atmosphären für 12 Studen täglich über 10 Tage).
Verapamil (VRP) wurde in einer Gesamtdosis von 200 mg/kg Körpergewicht subkutan verabfolgt. Bei hypoxischen Ratten reduzierte die Substanz die Werte für das Trockengewicht des Herzens, bezogen auf das Körpergewicht, erheblich.
Dieses Phänomen ist wahrscheinlich zu beziehen auf: 1. eine verminderte Aktiverung des kontraktilen Systems mit Abnahme der ATP-Spaltung als Ergebnis einer Blockade des Ca++-Influx in der Myokardzelle; 2. den Effekt von Verapamil auf die hypoxiebedingte pulmonalenm Hypertension und/oder 3. einen direkten Effekt der Substanz auf die Myokardzelle.
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Genovese, A., Chiariello, M., Cacciapuoti, A.A. et al. Inhibition of hypoxia-induced cardiac hypertrophy by verapamil in rats. Basic Res Cardiol 75, 757–763 (1980). https://doi.org/10.1007/BF01910453
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DOI: https://doi.org/10.1007/BF01910453