title: Novel selective cannabinoid CB(1) receptor antagonist MJ08 with potent in vivo bioactivity and inverse agonistic effects.
abstract: OBJECTIVE
  To characterize the biological profiles of MJ08, a novel selective CB(1) receptor antagonist.
  
  
  METHODS
  Radioligand binding assays were performed using rat brain and spleen membrane preparations. CB(1) and CB(2) receptor redistribution and intracellular Ca(2+) ([Ca(2+)](i)) assays were performed with IN CELL Analyzer. Inverse agonism was studied using intracellular cAMP assays, and in guinea-pig ileum and mouse vas deferens smooth muscle preparations. In vivo pharmacologic profile was assessed in diet-induced obesity (DIO) mice.
  
  
  RESULTS
  In radioligand binding assay, MJ08 selectively antagonized CB(1) receptor (IC(50)=99.9 nmol/L). In EGFP-CB(1)_U2OS cells, its IC(50) value against CB(1) receptor activation was 30.23 nmol/L (SR141716A: 32.16 nmol/L). WIN 55,212-2 (1 μmol/L) increased [Ca(2+)](i) in the primary cultured hippocampal neuronal cells and decreased cAMP accumulation in CHO-hCB(1) cells. MJ08 (10 nmol/L-10 μmol/L) blocked both the WIN 55,212-2-induced effects. Furthermore, MJ08 reversed the inhibition of electrically evoked twitches of mouse vas deferens by WIN 55,212-2 (pA(2)=10.29±1.05). MJ08 and SR141716A both showed an inverse agonism activity by markedly promoting the contraction force and frequency of guinea pig ileum muscle. MJ08 significantly increased the cAMP level in CHO-hCB(1) cells with an EC(50) value of 78.6 nmol/L, which was lower than the EC(50) value for SR141716A (159.2 nmol/L). Besides the more potent pharmacological effects of cannabinoid CB(1) receptor antagonism in DIO mice, such as reducing food intake, decreasing body weight, and ameliorating dyslipidemia, MJ08 (10 mg/kg) unexpectedly raised the fasted blood glucose in vivo.
  
  
  CONCLUSIONS
  MJ08 is a novel, potent and selective CB(1) receptor antagonist/inverse agonist with potent bioactive responses in vitro and in vivo that may be useful for disclosure the versatile nature of CB(1) receptors.
authors.affiliation: Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Cheng
authors.initials: C
authors.lastname: Xu
authors.forename: Hong-ying
authors.initials: HY
authors.lastname: Liu
authors.forename: Long
authors.initials: L
authors.lastname: Long
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Zhi-bing
authors.initials: ZB
authors.lastname: Zheng
authors.forename: Yun-de
authors.initials: YD
authors.lastname: Xie
authors.forename: Li-li
authors.initials: LL
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Li
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D050171:Dyslipidemias / Q000188:drug therapy*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009765:Obesity / Q000188:drug therapy*; D010880:Piperidines / Q000494:pharmacology*; D011720:Pyrazoles / Q000494:pharmacology*; D051381:Rats; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors*; D043885:Receptor, Cannabinoid, CB2 / Q000037:antagonists & inhibitors; D014649:Vas Deferens / Q000187:drug effects
chemical_list: C569010:(5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazol-3-yl)(piperidin-1-yl)methanone; D010880:Piperidines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D000242:Cyclic AMP