ISSN:
1573-7241
Keywords:
diltiazem
;
oxymyoglobin
;
hypoxia
;
isolated heart
;
Langendorff perfusion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The effect of diltiazem on the oxymyoglobin level was studied in the isolated rat heart during hypoxia. The heart was perfused with Krebs-Henseleit solution equilibrated with a gas mixture containing 95% O2+5% CO2 (normoxic perfusion solution) at a constant flow rate (9 ml/min) according to Langendorff's method. All the hearts were paced at 300 beats/min. The myocardial oxymyoglobin level (i.e., intracellular oxygen level) of the left ventricular surface was continuously measured by means of an optical technique. Diltiazem (infused into the aortic cannula for 10 minutes at concentrations of 0.72, 2.41, or 4.82 μM, expressed as the final concentration in the solution) decreased, the left ventricular pressure (LVP) and perfusion pressure (PP) dose dependently, and did not change the oxymyoglobin (MbO2) level during normoxic perfusion. Hypoxic perfusion (using a gas mixture containing 30% O2+5% CO2+65% N2) decreased the MbO2, LVP, and PP. Diltiazem (infused 5 minutes after the hypoxic perfusion) at a concentration of 2.41 or 4.82 μM increased the MbO2 level and further decreased the LVP, without affecting the PP. The low concentration (0.72 μM) of diltiazem, however, had practically no effect on these parameters. In summary, diltiazem in high concentrations decreased the LVP and increased the intracellular oxygen level of the myocardial cells during hypoxia, but not during normoxia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01856560
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