The role of striatal adenosine A2A receptors in regulation of the muscle tone in rats.
The aim of the present study was to assess contribution of striatal adenosine A2A receptors to regulation of the muscle tone in rats. The muscle tone was examined by a combined mechano- and electromyographic method, which measured simultaneously muscle resistance (MMG) of a rats hind foot to passive extension and flexion in the ankle joint and the electromyographic activity (EMG) of the antagonistic muscles: gastrocnemius and tibialis anterior. CGS 21680 (1 and 2 microg/0.5 microl), injected bilaterally into the rostral part of the striatum, dose-dependently increased both MMG and the EMG. The present results show that stimulation of striatal adenosine A2A receptors by CGS 21680 evokes parkinsonian-like muscle rigidity which may be due to activation of the GABAergic strio-pallidal pathway.
Wardas
J
J
Department of NeuroPsychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Kraków. wardas@if-pan.krakow.pl
Konieczny
J
J
Lorenc-Koci
E
E
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D000843:Ankle Joint / Q000187:drug effects*; D003342:Corpus Striatum / Q000187:drug effects; D004576:Electromyography; D008297:Male; D009127:Muscle Rigidity / Q000503:physiopathology*; D009129:Muscle Tonus / Q000187:drug effects* / Q000502:physiology; D010627:Phenethylamines / Q000494:pharmacology*; D058906:Purinergic P1 Receptor Agonists; D051381:Rats; D017208:Rats, Wistar; D043705:Receptor, Adenosine A2A; D018047:Receptors, Purinergic P1 / Q000187:drug effects* / Q000502:physiology
D010627:Phenethylamines; D058906:Purinergic P1 Receptor Agonists; D043705:Receptor, Adenosine A2A; D018047:Receptors, Purinergic P1; C061282:2-(4-(2-carboxyethyl)phenethylamino)-5'-N-ethylcarboxamidoadenosine; D000241:Adenosine