Onnen I, Olive G
J Pharmacol Methods. 1981 May;5(3):249-53. doi: 10.1016/0160-5402(81)90092-9.
Guinea pig ileums in Tyrode solution develop a progressive desensitization to the effects of atropine (2-min exposure). This desensitization, followed carefully by a simplified method, is significant from the fourth hr. On the other hand, no desensitization develops to the effects of equilibrium exposure to atropine.