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Evidence for the presence of cannabinoid CB 1 receptors in mouse urinary bladder
Author(s) -
Pertwee Roger G.,
Fernando Susanthi R.
Publication year - 1996
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1996.tb15643.x
Subject(s) - cannabinoid , chemistry , cannabinoid receptor , tetrahydrocannabinol , endocrinology , medicine , δ9 tetrahydrocannabinol , tetrodotoxin , anandamide , antagonist , urinary bladder , cannabinoid receptor agonists , receptor , pharmacology , biology , biochemistry
1 CP 55,244, (−)−11‐hydroxy‐dimethylheptyl‐Δ 8 ‐tetrahydrocannabinol, WIN 55,212‐2, Δ 9 ‐tetrahydro‐cannabinol, nabilone and anandamide each inhibited electrically‐evoked contractions of the mouse isolated urinary bladder in a concentration‐related manner, their EC 50 values being respectively 15.9, 18.27, 27.23, 1327.6, 1341.5 and 4950.3 nM. (+)‐11‐hydroxy‐dimethylheptyl‐Δ 8 ‐tetrahydrocannabinol was inactive at the highest concentration used (10 μ m ). 2 SR141716A (31.62 or 100 nM) produced parallel rightward shifts in the log concentration‐response curves of CP 55,244, (−)−11‐hydroxy‐dimethylheptyl‐Δ 8 ‐tetrahydrocannabinol, WIN 55,212‐2, Δ 9 ‐tetrahydrocannabinol and anandamide for inhibition of electrically‐evoked bladder contractions. The effect of the antagonist on the log concentration‐response curve of CP 55,244 was shown to depend on the concentration of SR141716A used (31.62 to 1000 nM). 3 The amplitudes of contractions evoked by acetylcholine or β, γ‐methylene‐L‐ATP were not decreased by 316.2 nM CP 55,244 or 3162 nM Δ 9 ‐tetrahydrocannabinol. Electrically‐evoked contractions were almost completely abolished by 200 nM tetrodotoxin. 4 The above results support the hypothesis that mouse urinary bladder contains prejunctional CB 1 cannabinoid receptors which can mediate inhibition of electrically‐evoked contractions, probably by reducing contractile transmitter release. 5 AM 630 which behaves as a cannabinoid receptor antagonist in the mouse isolated vas deferens did not antagonize the ability of CP 55,244 or Δ 9 ‐tetrahydrocannabinol to inhibit electrically‐evoked contractions of the mouse bladder. 6 SR141716A produced small but significant increases in the amplitude of electrically‐evoked contractions of the bladder suggesting that this tissue may release an endogenous cannabinoid receptor agonist or that some cannabinoid receptors in this tissue are precoupled to the effector system.