“本体论哲学”的发展，还是哲学形态的彻底革命——论理论与实际关系视野下的马克思哲学

Abstract

We have investigated the effect of isoprenaline on the amplitude of the transient contraction of isolated arteries induced by releasing the intracellular Ca with an agonist during incubation in a Ca-free solution. Under some conditions this force development is an indication of the amount of Ca in the intracellular store. Loading the store in high K+ solution in the presence of isoprenaline increases the amplitude of the subsequent contraction in Ca-free solution by 6 to 16% as compared to the control. The presence of isoprenaline during the loading procedure in the control solution with 5.9 mM K+ does not affect the amplitude of the subsequent contraction of the rabbit ear artery. In the rabbit coronary artery such pretreatment with isoprenaline inhibits the contraction to 40% of the control. These results indicate that beta-agonists may stimulate the Ca uptake in the intracellular store and, depending on the tissue, inhibit the influx of Ca.