[Effects of bradykinin and capsaicin intramuscular injections on stretch-evoked postsynaptic response of motoneurones of the gastrocnemius-soleus muscle].
Responses of gastrocnemius-soleus motoneurones to stretches of the homonymous muscles were recorded intracellularly in the decerebrated cats during intramuscular injections (IMI) of bradykinin or capsaicin into the muscles. Effects of IMI on EPSPs and spikes evoked by stretches of the G-S muscles were studied in 6 motoneurones. Stretch-evoked EPSPs and firing were predominantly suppressed after IMIs, with the exception of slight increase of EPSPs up to 150 s after bradykinin injection, followed by theirs distinct decrease. The suppression of spike activity was followed by restoration within 500-800 s after bradykinin injection. Stretch-evoked EPSPs and firing were depressed after capsaicin injection; control level of motoneurones activity was seemed to be unrecoverable for quite a long time. No background IPSPs were observed after algesic injections and presynaptic inhibition was considered as plausible reason for the observed suppression of motoneurones activity.
L A
LA
Buhaĭchenko
O I
OI
Piliavs'kyĭ
O I
OI
Kostiukov
D000818:Animals; D001920:Bradykinin / Q000008:administration & dosage / Q000494:pharmacology*; D002211:Capsaicin / Q000008:administration & dosage / Q000494:pharmacology*; D002415:Cats; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects*; D007273:Injections, Intramuscular; D008297:Male; D009046:Motor Neurons / Q000187:drug effects* / Q000502:physiology; D009470:Muscle Spindles / Q000187:drug effects* / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D010146:Pain / Q000503:physiopathology
D002211:Capsaicin; D001920:Bradykinin