Effects of the endocannabinoid transport inhibitors AM404 and UCM707 on diabetic neuropathy in rats.
1. Diabetic rats display increased pain responses following injection of formalin into the paw, suggesting the presence of hyperalgesia. In the present study, we investigated the efficacy of the systemic administration of the endocannabinoid transport inhibitors UCM707 and AM404 (1, 10 and 50 mg/kg, i.p.) on hyperalgesia during the formalin test in streptozocin (STZ)-induced diabetic rats. 2. Nociceptive testing was performed in male adult Wistar rats 4 weeks after the onset of hyperglycaemia. At the end of the experiment, all rats were weighed and then underwent plasma glucose measurements. 3. Diabetes caused significant hyperalgesia during both phases of the formalin test. At 10 and 50 mg/kg, both UCM707 and AM404 reversed chemical hyperalgesia in diabetic rats. UCM707 (10 and 50 mg/kg) caused less intensive nociceptive behaviour during both phases of the test, whereas AM404 (10 and 50 mg/kg) only affected pain scores during Phase 1 of the formalin test. At 1 mg, neither drug had any effect on pain behaviour in control and diabetic groups compared with their respective controls. Neither UCM707 nor AM404 had any effect on bodyweight or plasma glucose levels of treated compared with non-treated rats at any of the doses tested. 4. The results of the present study indicate that systemic administration of UCM707 and AM404 is effective in ameliorating chemical hyperalgesia in STZ-diabetic rats. Thus, endocannabinoid transport inhibitors may have potential in the treatment of painful diabetic neuropathy.
Department of Biology, School of Basic Sciences, Bu-Ali Sina University, Hamadan, Iran. p.hasanein@basu.ac.ir
Parisa
P
Hasanein
Nepton
N
Soltani
D000818:Animals; D001095:Arachidonic Acids / Q000627:therapeutic use*; D001786:Blood Glucose / Q000187:drug effects; D001835:Body Weight; D063385:Cannabinoid Receptor Modulators / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000188:drug therapy*; D003929:Diabetic Neuropathies / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D063388:Endocannabinoids; D005663:Furans / Q000627:therapeutic use*; D006930:Hyperalgesia / Q000150:complications / Q000188:drug therapy*; D006943:Hyperglycemia / Q000150:complications / Q000188:drug therapy*; D008297:Male; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy; D010147:Pain Measurement / Q000187:drug effects; D050480:Plasma Membrane Neurotransmitter Transport Proteins / Q000037:antagonists & inhibitors*; D053284:Polyunsaturated Alkamides / Q000627:therapeutic use*; D051381:Rats
D001095:Arachidonic Acids; D001786:Blood Glucose; D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D005663:Furans; C443680:N-(3-furylmethyl)eicosa-5,8,11,14-tetraenamide; D050480:Plasma Membrane Neurotransmitter Transport Proteins; D053284:Polyunsaturated Alkamides; C107594:N-(4-hydroxyphenyl)arachidonylamide