TY - JOUR

T1 - Novel monohydroxamate drugs attenuate myocardial reperfusion-induced arrhythmias

AU - Collis, C S

AU - Rice-Evans, C

AU - Davies, Michael Jonathan

PY - 1996/4

Y1 - 1996/4

N2 - The novel monohydroxamates N-methyl hexanoylhydroxamic acid, N-methyl acetohydroxamic acid, and N-methyl butyrohydroxamic acid have antioxidant and iron chelating properties. They attenuated reperfusion-induced contractile dysfunction following long periods of ischaemia (50 min) in the isolated rat heart. Here we compare their effects and that of the trihydroxamate desferrioxamine on reperfusion-induced arrhythmias following short duration ischaemia (10 min). Isolated rat hearts were perfused by the Langendorff method, subjected to regional ischaemia and reperfusion. Arrhythmias induced during the first 5 min of reperfusion were quantified. Drugs (all at 150 microM) were introduced during the last 2 min of ischaemia and remained throughout reperfusion. Although the monohydroxamate- and desferrioxamine-treated hearts showed a reduction in the incidence of ventricular tachycardia and fibrillation, only the reduction in the incidence of sustained fibrillation ( > 3 min duration) in N-methyl acetohydroxamic acid--(27%), N-methyl hexanoylhydroxamic acid--(27%) and desferrioxamine-treated hearts (20%) was statistically significant (p < 0.05 vs control 73%; n = 15). There was a reduction in the severity of the arrhythmias, manifest as a significant increase in the duration of sinus rhythm in all the monohydroxamate-treated hearts, and a significant reduction (vs control 218 +/- 29 s; mean +/- SEM) in the duration of ventricular fibrillation in hearts treated with N-methyl acetohydroxamic acid (101 +/- 31 s) and desferrioxamine (112 +/- 30 s). This improvement was offset by an increase in the duration of ventricular tachycardia, in hearts treated with N-methyl acetohydroxamic acid, N-methyl butyrohydroxamic acid and desferrioxamine. These results suggest that these novel monohydroxamates, particularly N-methyl acetohydroxamic acid, attenuate reperfusion-induced arrhythmias in this model when introduced during the ischaemic period.

AB - The novel monohydroxamates N-methyl hexanoylhydroxamic acid, N-methyl acetohydroxamic acid, and N-methyl butyrohydroxamic acid have antioxidant and iron chelating properties. They attenuated reperfusion-induced contractile dysfunction following long periods of ischaemia (50 min) in the isolated rat heart. Here we compare their effects and that of the trihydroxamate desferrioxamine on reperfusion-induced arrhythmias following short duration ischaemia (10 min). Isolated rat hearts were perfused by the Langendorff method, subjected to regional ischaemia and reperfusion. Arrhythmias induced during the first 5 min of reperfusion were quantified. Drugs (all at 150 microM) were introduced during the last 2 min of ischaemia and remained throughout reperfusion. Although the monohydroxamate- and desferrioxamine-treated hearts showed a reduction in the incidence of ventricular tachycardia and fibrillation, only the reduction in the incidence of sustained fibrillation ( > 3 min duration) in N-methyl acetohydroxamic acid--(27%), N-methyl hexanoylhydroxamic acid--(27%) and desferrioxamine-treated hearts (20%) was statistically significant (p < 0.05 vs control 73%; n = 15). There was a reduction in the severity of the arrhythmias, manifest as a significant increase in the duration of sinus rhythm in all the monohydroxamate-treated hearts, and a significant reduction (vs control 218 +/- 29 s; mean +/- SEM) in the duration of ventricular fibrillation in hearts treated with N-methyl acetohydroxamic acid (101 +/- 31 s) and desferrioxamine (112 +/- 30 s). This improvement was offset by an increase in the duration of ventricular tachycardia, in hearts treated with N-methyl acetohydroxamic acid, N-methyl butyrohydroxamic acid and desferrioxamine. These results suggest that these novel monohydroxamates, particularly N-methyl acetohydroxamic acid, attenuate reperfusion-induced arrhythmias in this model when introduced during the ischaemic period.

KW - Animals

KW - Anti-Arrhythmia Agents

KW - Cardiotonic Agents

KW - Electrocardiography

KW - Hemodynamics

KW - Hydroxamic Acids

KW - In Vitro Techniques

KW - Male

KW - Molecular Structure

KW - Myocardial Contraction

KW - Myocardial Reperfusion Injury

KW - Rats

KW - Rats, Wistar

KW - Ventricular Fibrillation

M3 - Journal article

C2 - 9026351

VL - 28

SP - 405

EP - 413

JO - International Journal of Biochemistry & Cell Biology

JF - International Journal of Biochemistry & Cell Biology

SN - 1357-2725

IS - 4

ER -