| Popis: |
The investigation were performed on trabeculae extracted from right auricle of IHD patients aged 40-55 years during aortocoronary bypass. In transitory increase of stimulation frequency from 0.5 up to 1 Hz, a significant decrease of developed tension (Tmax), of the rate of its increase (T'max) and decrease (T'min) by 37% on the average were observed. On the contrary, stimulation frequency decrease up to 0.1 Hz caused, Tmax, T'min and T'max increase, by 20 + 4, 16 + 3 and 13 + 4 respectively (p0.05). The effect of hypercalcium (4 mM Ca2+) solution led to Tmax increase by 324%, T'max--by 254% and T'min by 383%, meanwhile the T'min/T'max ratio being initially equal to 0.3, increased to 0.4. Adrenalin caused not only the same Tmax increase (by 322%) as did Ca2+ but the same response of the rate parameters (T'min/T'max, 0.4--fold). The decrease of stimulation frequency to 0.1 Hz associated with Ca2+ or adrenalin effects resulted in additional increase of contractile activity. It was concluded that the contractile apparatus of myocardium in IHD patients retained sufficient functional reverse, accompanied by changes in the regulation of Ca(2+)-transporting systems. |
