Goldner M M, Rosen G M
Res Commun Chem Pathol Pharmacol. 1977 Mar;16(3):393-400.
The spin labeled acetylcholine analog, SL-2, which is a potent, non-stimulating muscarinic antagonist on the isolated frog heart, is a potent agonist a low concentrations (3x10-5 M) and an antagonist at slightly higher concentrations (4.5x10-5 M) on the mixed cholinergic receptors of the leech. Ion the other hand, the spin labeled acetylcholine analog, SL-1, possesses no agonist activity while it retains the antagonist activity of SL-2. Furthermore, the spin labeled analog, SL-3, which causes hyperpolarization and a decrease in action potential frequency, exhibits neither agonist nor antagonist activity.
自旋标记的乙酰胆碱类似物SL-2，在离体蛙心上是一种强效的、无刺激作用的毒蕈碱拮抗剂，而在水蛭的混合胆碱能受体上，它在低浓度（3×10⁻⁵M）时是强效激动剂，在稍高浓度（4.5×10⁻⁵M）时是拮抗剂。另一方面，自旋标记的乙酰胆碱类似物SL-1不具有激动剂活性，但保留了SL-2的拮抗剂活性。此外，自旋标记类似物SL-3可引起超极化并降低动作电位频率，它既不表现出激动剂活性也不表现出拮抗剂活性。
