[Changes in lipid spectrum in rats with chronic heart failure of different severity on the background of angiotensin-converting enzyme inhibitors and beta-adrenoblockers].

The character of lipid spectrum changes in rats with experimental heart failure of non-ischemic genesis depended on its severity. In mild heart failure there was found an increase in the low density lipoprotein levels, whereas in the severe one--a decrease of total cholesterol levels at the expense of the low density lipoproteins. The ACE inhibitors produced no significant changes in the lipid spectrum.

[Effect of angiotensin-converting enzyme inhibitors, beta-adrenoblockers, and their combinations on survival and plasma catecholamine levels in rats with chronic heart failure with induced exacerbations].

By using model of chronic heart failure (CHF) occurring with induced decompensations, it was shown that inhibitors of angiotensin-converting enzyme (ACE) and beta-adrenoblockers promoted to different degree the correction of hypercatecholaminemia and an increase of survival of rats. The most pronounced effect was characteristic of beta-adrenoblockers atenolol, propranolol, and carvedilol. The lower activity was demonstrated by other adrenoblockers that had no intrinsic sympathomimetic activity, as well as captopril.

[Plasma lipid spectrum and survival in rats with heart failure varied by severity under the influence of neurohormonal modulators].

In rats with relatively mild chronic heart failure (CHF) there was an increase in plasma LDL levels. In turn, in severe CHF it was revealed a significant decrease in total cholesterol concentration due to LDL levels decline. ACE inhibitors (captopril, enalapril and lisinopril) and the most selective beta1-adrenoblockers (metoprolol, nebivolol) had not any significant influence on plasma lipids.

Peculiarities of heart rhythm variability in narcotized and immobilized wakeful rats during blockade of calcium channels.

In narcotized rats, verapamil and cinnarizine modified some heart rate variability (HRV) indices and heart rate (HR) indicating up-regulation of parasympathetic tone in contrast to nifedipine that elevated activity of sympathetic subdivision of ANS producing no influence on HR. In wakeful stressed rats, the time-domain and geometric analysis established that verapamil decreased HR and up-regulated sympathetic tone; nifedipine elevated sympathetic tone and produced no effect on HR, while cinnarizine enhanced parasympathetic tone without any effect on HR. Spectrum analysis of HRV revealed probable activation of some other neurohumoral mechanisms by the employed calcium blockers.

Heart rate variability in conscious and anesthetized rats under the action of angiotensin converting enzyme inhibitors.

We studied the effects of three various angiotensin converting enzyme inhibitors (enalapril, lisinopril and quinapril) on heart rhythm variability in anesthetized and immobilized rats. In all cases (except for quinapril in experiments on anesthetized animals), the preparations reduced the total rhythm variability and, according to spectrum analysis, increased activity of the parasympathetic autonomic nervous system to different degrees and decreased sympathetic tone. Quinapril and lisinopril produced the most pronounced influence on heart rhythm in anesthetized rats; enalapril was less potent in this respect.