Muscarinic receptors on rat lymphocytes; internalization of receptor-ligand complex.
In the light of the data presented, the previously described explanation of the unusual shape of the kinetic curve of the muscarinic antagonist 3H-QNB binding to rat lymphocytes, with apparent maximum of bound radioactivity after 5 min of incubation, followed by decrease of specific binding, is not satisfactory. The kinetics of this binding carried out at 4 degrees C, 20 degrees C and 37 degrees C, or in the presence of the metabolic poison sodium azide, suggests involvement of an energy-consuming mechanism in this process. The surface receptors, sensitive to bacterial protease degradation before 3H-QNB binding, become somehow resistant to this protease action after 5 min of incubation of the cells with 3H-QNB. A possible explanation for this phenomenon, based on internalization in cell endosomes, is presented.
Bortkiewicz
H
H
Department of Pathophysiology, Institute of Rheumatology, Warsaw, Poland.
Maśliński
W
W
Ryzewski
J
J
D000818:Animals; D001386:Azides / Q000494:pharmacology; D008024:Ligands; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D008297:Male; D010277:Parasympathomimetics / Q000037:antagonists & inhibitors; D010447:Peptide Hydrolases / Q000378:metabolism; D011812:Quinuclidines / Q000378:metabolism*; D011813:Quinuclidinyl Benzilate / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000378:metabolism*; D019810:Sodium Azide; D013696:Temperature; D014316:Tritium
D001386:Azides; D008024:Ligands; D010277:Parasympathomimetics; D011812:Quinuclidines; D011976:Receptors, Muscarinic; D014316:Tritium; D011813:Quinuclidinyl Benzilate; D019810:Sodium Azide; D010447:Peptide Hydrolases