Characterization of muscarinic receptors in human pancreatic membranes.
Crude membranes (27,000 x g pellets) from three normal human pancreata were prepared. Muscarinic receptors were investigated by the ability of three antagonists (atropine, pirenzepine, and AF-DX 116) and three agonists (carbamylcholine, oxotremorine, and pilocarpine) to inhibit [3H]NMS binding. These receptors showed for pirenzepine and AF-DX 116 a M2 beta specificity, typical of secretory glands and smooth muscle, that was comparable to that of rat pancreatic membranes, i.e., a low affinity for the two antagonists (Ki of 0.4 and 0.2 microM, respectively). In addition, these receptors were predominantly in a low affinity state for the agonist carbamylcholine (Ki of 100 microM).
Waelbroeck
M
M
Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium.
Camus
J
J
Tastenoy
M
M
De Neef
P
P
Scemama
J L
JL
Fourmy
D
D
Vaysse
N
N
Pradayrol
L
L
Robberecht
P
P
Christophe
J
J
D002217:Carbachol / Q000378:metabolism; D002462:Cell Membrane / Q000032:analysis / Q000648:ultrastructure; D006801:Humans; D010095:Oxotremorine / Q000378:metabolism; D010179:Pancreas / Q000032:analysis* / Q000648:ultrastructure; D010862:Pilocarpine / Q000378:metabolism; D010890:Pirenzepine / Q000031:analogs & derivatives / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000032:analysis* / Q000378:metabolism
D011976:Receptors, Muscarinic; D010862:Pilocarpine; D010890:Pirenzepine; D010095:Oxotremorine; D002217:Carbachol; C048593:otenzepad