Acetylcholine synthesizing activity and nicotinic binding sites in rat hind limb muscles during reinnervation.
Acetylcholine synthesizing (ACh-s) activity and binding of the nicotinic ligands 3H-alpha-bungarotoxin (alpha-Btx) and 3H-d-tubocurarine (d-TC) were analysed in rat hind limb muscles for up to 6 months after a cryolesion of the sciatic nerve. Muscles of the contralateral leg served as controls. After cryolesion there was a rapid decrease in ACh-s activity parallel to a considerable increase in alpha-Btx binding. A clearcut increase in ACh-s activity was first seen at 32 days and complete restoration in ACh-s activity was seen from 2-3 months postoperatively. From the 16th day there was a rapid decrease in alpha-Btx bindings sites and initial values were seen at the 32nd day postoperatively. D-TC binding sites were relatively unchanged during the experimental period. The first neurophysiological signs of reinnervation were seen at 16 days. The rats were observed to move normally about 2 months postoperatively. Normalization of alpha-Btx binding sites seems to be an earlier sign of reinnervation than normalization of ACh-s activity.
D000109:Acetylcholine / Q000378:metabolism*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002038:Bungarotoxins / Q000378:metabolism; D003714:Denervation; D005071:Evoked Potentials / Q000187:drug effects; D005615:Freezing; D006614:Hindlimb; D009132:Muscles / Q000294:innervation / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000378:metabolism*; D012584:Sciatic Nerve / Q000502:physiology; D014403:Tubocurarine / Q000378:metabolism
D002038:Bungarotoxins; D011950:Receptors, Cholinergic; D011978:Receptors, Nicotinic; D000109:Acetylcholine; D014403:Tubocurarine