Vornovitskiĭ E G, Ignat'eva V B, Gollash M, Kulikov V I, Kuznetsova T I, Khodorov B I
Biull Eksp Biol Med. 1989 Aug;108(8):137-9.
The effects of platelet activating factor (PAF) and three its antagonists on the transmembrane intracellular potentials and stimulated (0.5 Hz) contraction amplitude (CA) of the left auricle has been studied. PAF (1-5 X 10(-7) M) was added to the standard Tyrode solution or the same perfusing solution with 15 mM K+, and 6 mM Ca++ (t = 30 degrees C, pH = 7,2). PAF induced the straight cardio-depressing action: the CA always was suppressed during 20 min. The electrical activity was depressed in parallel; in the Tyrode the action potential (AP) duration was lowered, but in the atrial depolarized preparations PAF resulted in a decrease of the slow calcium potential (Ca-AP) amplitude from 100% to 20.2 +/- 2.0%. After 20 min PAF-acting the perfusing solutions contained also one of PAF-antagonists. Antagonist U-66985 led to the weakening of the PAF-depressing effects in the myocardium U-66985 is also able to increase electrical and mechanical activity in myocardium depressed by the blood serum from patients with virulent infections.
研究了血小板活化因子（PAF）及其三种拮抗剂对左心房跨膜细胞内电位和刺激（0.5赫兹）收缩幅度（CA）的影响。将PAF（1 - 5×10⁻⁷ M）添加到标准台氏液或含有15 mM K⁺和6 mM Ca²⁺的相同灌注液中（温度t = 30℃，pH = 7.2）。PAF引起直接的心脏抑制作用：在20分钟内CA始终受到抑制。电活动也同时受到抑制；在台氏液中动作电位（AP）持续时间缩短，但在心房去极化制剂中，PAF导致慢钙电位（Ca - AP）幅度从100%降至20.2±2.0%。PAF作用20分钟后，灌注液中还含有一种PAF拮抗剂。拮抗剂U - 66985导致PAF对心肌抑制作用的减弱。U - 66985还能够增加被恶性感染患者血清抑制的心肌的电活动和机械活动。
