Gene-gene interaction in the RAS system in the predisposition to myocardial infarction in elder population of St. Petersburg (Russia).

The aim of this study was to estimate the frequencies of some DNA polymorphisms of two genes of the renin-angiotensin system (RAS), M235T angiotensinogen gene and insertion-deletion polymorphism in angiotensin-converting enzyme gene, in older (>55 years old) myocardial infarction survival and control groups. For this purpose 198 myocardial infarction (MI) patients and 152 randomly selected healthy persons have been analyzed. We have not found any differences in allele and genotype distribution in the above-mentioned genes for either group.

[Role of structural polymorphism of the angiotensin-converting enzyme gene in the development of myocardial infarction].

Genotyping of angiotensin-converting enzyme (ACE) using polymerase chain reaction was conducted in 184 males with acute macrofocal infarction versus 72 males free of arterial hypertension and ischemic heart disease (controls). The age of the patients ranged from 30 to 70 years. Normotensive patients who survived myocardial infarction at the age under 60 had significantly more frequent genotype DD (in the system I/D-polymorphism of ACE gene) than controls or hypertensive patients.

[Mechanism of the antiarrhythmic effect of laser irradiation].

Acute experiments were performed to study the role of afferent impulses from the heart receptors which pass by different vagal fibers during intraatrial laser irradiation. Double laser irradiation of the right atrium seemed more effective than a single one as to decreasing ventricular arrhythmias during cardiac ischemia. It is shown that the antiarrhythmic effect of intraatrial laser irradiation may be due to the change of the afferent information passing by myelinated vagal fibers.