[The effect of amlodipine, bisoprolol on the myocardial ultrastructure of the hypertensive rats].

Abstract Calcium channel blockers and beta1-adrenoblockers are effective antihypertensive agents, but their cell protective properties are not investigated well. Spontaneously hypertensive rats received a 10 mg/kg/day amlodipine dose and 25 mg/kg/day bisoprolol dose via an orogastric tube during three months. We performed examination of the myocardium's fragments under a scanning electron microscope. Morphometric investigation of mitochondrions we performed using special program what is named "ORGANELLE". Amlodipine significantly normalizes the ultrastructure of the myocardium. This antihypertensive drug prevented the signs of over-contractility of myofibrils. Amlodipine causes the fusion mitochondrions which has compensatory character on the background of good safety of mitochondrial ultrastructures. Another feature of amlodipine is a significant increase in the number of capillaries. Bisoprolol significantly reduced over-contractility of the myofibrils, but the signs of dystrophic-destructive processes in myofibrils and mitochondrions of cardiomyocytes remained. Bisoprolol improved the condition of the endothelial cells, but the activation of the functional activity of these cells has not been observed. The combined use of two antihypertensive drugs amlodipine and bisoprolol led to a better recovery of myofibrils than their separate use, whereas the effect on mitochondrions noted similar as in the group of rats received bisoprolol and that effect was worse than during amlodipine's monotherapy. Also we didn't reveal a reason to combine these drugs after analysis of the effect of the drug combination on the conditions of blood microvessels, which number was increased compared with hypertensive rats, but significantly less than when rats received only amlodipine. These essential cell-protective effects of amlodipine and bisoprolol in spontaneously hypertensive rats could be a significant additional factor in the treatment of hypertension complicated with pathological changes in the heart.