[Chemoreflex modification of the myocardial contractility of rabbits].
The effects of arterial hypoxia on the minute ventilation (AMV), the heart interval (HI), the contractility index (KI = (P/P) max., the left ventricular systolic pressure (LVSP), and the pressure-increase-time RP were tested before and after infusion of a selective stimulator of the arterial chemoreceptors (0.5 mg/kg Almitrine-Bismesylate). The arterial blood-pH and the paO2 were increased by Almitrine whereas the paCO2 was decreased significantly. The AMV is elevated, the heart interval and the RP-interval are reduced, KI and LVSP increase after Almitrine. The hypoxia-effects after changing the paO2 from 19 to 9 kPa are an increase of AMV, KI, LVSP and a shortening of HI and RP. These effects were intensified by Almitrine. The hypoxia effects were not changed by vagotomy. A correlation between the increase of the respiration and the appertaining cardiac effects was not discovered.
Opitz
H
H
Julius-Bernstein-Institut für Physiologie, Martin-Luther-Universität Halle-Wittenberg Bereich Medizin.
Scheufler
K
K
D015765:Almitrine / Q000494:pharmacology*; D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D002628:Chemoreceptor Cells / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D009200:Myocardial Contraction / Q000187:drug effects*; D010100:Oxygen / Q000097:blood; D011817:Rabbits; D012119:Respiration / Q000187:drug effects
D002245:Carbon Dioxide; D015765:Almitrine; D010100:Oxygen
Chemoreflektorische Beeinflussung der myokardialen Kontraktilität des Kaninchens.