Alabovskiĭ V V, Vinokurova A A
Vestn Ross Akad Med Nauk. 1996(5):45-51.
Nucleotides were examined for their effects on the development of calcium paradox in the isolated rat heart. The protective action of nucleotides was found to be unassociated with the structure of their nitrogen base. The products of extracellular hydrolysis, such as ribose (deoxyribose), uridine or adenosine at a concentration of 100 microM caused no less protective effects than nucleotides. In calcium paradox, the protective action of adenosine was not suppressed by theophylline, but sensitive to dipyridamole and transmembrane Na gradient values. Nucleotides and their hydrolytic products were demonstrated to exert a positive myocardial effect not only at the physiological (140 microM), but increased Na ion concentrations. The high extracellular Na concentration-induced potentiation of the protective action of nucleotides or their hydrolytic products was blocked by strophanthin. It is suggested that the high Na gradient can increase the protective action of nucleotides and their hydrolytic products due to decreased Na-Ca metabolism and to the altered metabolism of nucleotide hydrolytic products.
研究了核苷酸对离体大鼠心脏钙反常发展的影响。发现核苷酸的保护作用与其氮碱基结构无关。细胞外水解产物，如浓度为100微摩尔的核糖（脱氧核糖）、尿苷或腺苷，其保护作用不亚于核苷酸。在钙反常中，腺苷的保护作用不受茶碱抑制，但对双嘧达莫和跨膜钠梯度值敏感。已证明核苷酸及其水解产物不仅在生理浓度（140微摩尔）时对心肌有积极作用，而且在钠离子浓度增加时也有此作用。高细胞外钠浓度诱导的核苷酸或其水解产物保护作用的增强被毒毛花苷阻断。提示高钠梯度可通过降低钠钙代谢和改变核苷酸水解产物的代谢来增强核苷酸及其水解产物的保护作用。
