Stengel_2002_Am.J.Physiol.Regul.Integr.Comp.Physiol_282_R1443

Reference

Title : M(3)-receptor knockout mice: muscarinic receptor function in atria, stomach fundus, urinary bladder, and trachea - Stengel_2002_Am.J.Physiol.Regul.Integr.Comp.Physiol_282_R1443
Author(s) : Stengel PW , Yamada M , Wess J , Cohen ML
Ref : American Journal of Physiology Regul Integr Comp Physiol , 282 :R1443 , 2002
Abstract :

Negative chronotropic and smooth muscle contractile responses to the nonselective muscarinic agonist carbamylcholine were compared in isolated tissues from M(3)-muscarinic receptor knockout and wild-type mice. Carbamylcholine (10(-8)-3.0 x 10(-5) M) induced a concentration-dependent decrease in atrial rate that was similar in atria from M(3)-receptor knockout and wild-type mice, indicating that M(3) receptors were not involved in muscarinic receptor-mediated atrial rate decreases. In contrast, the M(3) receptor was a major muscarinic receptor involved in smooth muscle contraction of stomach fundus, urinary bladder, and trachea, although differences existed in the extent of M(3)-receptor involvement among the tissues. Contraction to carbamylcholine was virtually abolished in urinary bladder from M(3)-receptor knockout mice, suggesting that contraction was predominantly due to M(3)-receptor activation. However, approximately 50-60% maximal contraction to carbamylcholine occurred in stomach fundus and trachea from M(3)-receptor knockout mice, indicating that contraction in these tissues was also due to M(2)-receptor activation. High concentrations of carbamylcholine relaxed the stomach fundus from M(3)-receptor knockout mice by M(1)-receptor activation. Thus M(3)-receptor knockout mice provided unambiguous evidence that M(3) receptors 1) play no role in carbamylcholine-induced atrial rate reduction, 2) are the predominant receptor mediating carbamylcholine-induced urinary bladder contractility, and 3) share contractile responsibility with M(2) receptors in mouse stomach fundus and trachea.

PubMedSearch : Stengel_2002_Am.J.Physiol.Regul.Integr.Comp.Physiol_282_R1443
PubMedID: 11959688

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Citations formats

Stengel PW, Yamada M, Wess J, Cohen ML (2002)
M(3)-receptor knockout mice: muscarinic receptor function in atria, stomach fundus, urinary bladder, and trachea
American Journal of Physiology Regul Integr Comp Physiol 282 :R1443

Stengel PW, Yamada M, Wess J, Cohen ML (2002)
American Journal of Physiology Regul Integr Comp Physiol 282 :R1443