Effects of aluminum on the mechanical and electrical activity of the Langendorff-perfused rat heart.
The effect of aluminum (Al3+) chloride (1, 5, 10, 50 and 100 microM) on myocardial electromechanical activity was studied in 10 Langendorff-perfused hearts from adult female Wistar rats. Al3+ decreased the development of isovolumic systolic pressure from 34.3 +/- 2.95 mmHg under control conditions to 11.8 +/- 1.53 mmHg at 100 microM AlCl3 (P < 0.01) (diastolic pressure = 0 mmHg). The atrial and ventricular rates also decreased, but only with AlCl3 concentrations greater than 1 microM (from 180 +/- 5 to 94 +/- 11 bpm for atrial rate and from 180 +/- 5 to 78 +/- 7 bpm for ventricular rate). Reduction of coronary flow was also observed, reaching 60% at 100 microM Al3+. A delay in atrioventricular conduction occurred at 10 microM Al3+, increasing progressively up to 100 microM (62.3 +/- 4 ms in the Al(3+)-free solution to 143 +/- 34 ms in the presence of 100 microM Al3+, P < 0.01, ANOVA). QRS duration did not change as a function of increasing Al3+ concentrations (37.1 +/- 1.7 ms in the Al(3+)-free solution vs 32.1 +/- 1.6 ms in the presence of 100 microM Al3+). No qualitative changes in ECG were observed. These data show that the toxic effects of Al3+ on the myocardium are reflected in reduced systolic pressure development and coronary flow and increased PR interval. These effects are discussed in terms of the inhibition of nucleotide hydrolysis by Al3+.
Gomes
M G
MG
Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brasil.
Moreira
C A
CA
Mill
J G
JG
Massaroni
L
L
Oliveira
E M
EM
Stefanon
I
I
Vassallo
D V
DV
D000535:Aluminum / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002712:Chlorides / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D009994:Osmolar Concentration; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar
D002712:Chlorides; D000535:Aluminum