Watts J A, Hoogmoed R P
Biochem Pharmacol. 1984 Feb 1;33(3):365-9. doi: 10.1016/0006-2952(84)90227-2.
The heart rate of the isolated, perfused, working rat heart was significantly and equally depressed by 1 X 10(-6)M acetylcholine (ACh) and by 6 X 10(-5)M 4-ketoamyltrimethylammonium (4K), a cholinomimetic agonist. Dimethyl sulfoxide (DMSO) (10 microliter/ml, 140 mM) strongly potentiated the effect of ACh but did not alter the effect of 4K. DMSO (10 microliter/ml, 140 mM) strongly potentiated the effect of ACh but did not alter the effect of 4K. DMSO (10 microliter/ml, 140 mM final concentration) alone had no significant effect upon heart rate when added to the perfusate in incremental additions of 1 microliter X (ml perfusate)-1 X min-1 over a 10-min period. The specific activity of atrial homogenate cholinesterase was 48.8 +/- 3.46 nmoles X min-1 X (mg protein)-1 (mean +/- S.E.M.), 38.2 +/- 1.60 for butyrylcholinesterase, and 11.2 +/- 0.86 for acetylcholinesterase (AChE). True AChE activity (measured in the presence of a maximally effective concentration of tetraisopropylpyrophosphoramide) had a Vmax of 13.4 +/- 0.17 nmoles X min-1 X mg protein)-1 and an apparent Km value of 1 X 10(-4)M acetylthiocholine. At this Km substrate concentration, DMSO inhibited atrial AChE activity (I50 = 9 microliter/ml). At the concentration tested, DMSO inhibited atrial AChE and potentiated ACh effects.
1×10⁻⁶M乙酰胆碱（ACh）和6×10⁻⁵M 4-酮戊基三甲基铵（4K，一种拟胆碱激动剂）可使离体、灌注、工作状态的大鼠心脏心率显著且同等程度地降低。二甲基亚砜（DMSO）（10微升/毫升，140毫摩尔）强烈增强了ACh的作用，但未改变4K的作用。DMSO（10微升/毫升，140毫摩尔）强烈增强了ACh的作用，但未改变4K的作用。在10分钟内以1微升×（每毫升灌注液）⁻¹×分钟⁻¹的增量添加到灌注液中时，单独的DMSO（最终浓度10微升/毫升，140毫摩尔）对心率没有显著影响。心房匀浆胆碱酯酶的比活性为48.8±3.46纳摩尔×分钟⁻¹×（毫克蛋白质）⁻¹（平均值±标准误），丁酰胆碱酯酶为38.2±1.60，乙酰胆碱酯酶（AChE）为11.2±0.86。真正的AChE活性（在最大有效浓度的四异丙基焦磷酰胺存在下测量）的Vmax为13.4±0.17纳摩尔×分钟⁻¹×毫克蛋白质⁻¹，乙酰硫代胆碱的表观Km值为1×10⁻⁴M。在这个Km底物浓度下，DMSO抑制心房AChE活性（I50 = 9微升/毫升）。在所测试的浓度下，DMSO抑制心房AChE并增强ACh的作用。
