In vitro quantitative autoradiography of [125I]alpha-bungarotoxin binding at the motor end-plates of experimental autoimmune myasthenia gravis.
A quantitative evaluation was made of nicotinic acetylcholine receptors (AChR) at the motor end-plates in experimental autoimmune myasthenia gravis (EAMG). Female Lewis rats were immunized with AChR protein purified from electric organs of Narke japonica. The forelimb digit extensor muscle obtained in the chronic stage of the controls and EAMG were studied using [125I]alpha-bungarotoxin, in vitro and autoradiographically. The maximum binding capacity (Bmax) values of the controls and EAMG were calculated to be 237.7 +/- 13.0 fmol/mg (n = 4) and 42.0 +/- 4.1 fmol/mg (n = 4), respectively (P less than 0.001), and the dissociation constant (Kd) values were 11.7 +/- 1.6 nM and 7.6 +/- 0.9 nM, respectively. This in vitro autoradiographic method revealed a quantitative reduction of AChR at the motor end-plates in EAMG.
Motomura
M
M
Department of Internal Medicine I, Nagasaki University School of Medicine, Japan.
Niwa
M
M
Kataoka
Y
Y
Ootsuru
I
I
Yoshimura
T
T
Tsujihata
M
M
Nagataki
S
S
D000818:Animals; D001323:Autoantibodies / Q000097:blood; D001327:Autoimmune Diseases / Q000276:immunology / Q000378:metabolism*; D002038:Bungarotoxins / Q000378:metabolism*; D005260:Female; D009045:Motor Endplate / Q000378:metabolism*; D009157:Myasthenia Gravis / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D011917:Rats, Inbred Lew; D011978:Receptors, Nicotinic / Q000378:metabolism*; D064569:alpha7 Nicotinic Acetylcholine Receptor
D001323:Autoantibodies; D002038:Bungarotoxins; C579165:Chrna7 protein, rat; D011978:Receptors, Nicotinic; D064569:alpha7 Nicotinic Acetylcholine Receptor