Muscarinic receptor subtype in porcine coronary artery.
The specific binding of (-)-[3H]QNB (quinuclidinyl benzilate) in membrane fractions of porcine coronary artery was saturable, of high affinity and stereoselective. It has been shown that there exist (-)-[3H]QNB binding sites with high (Ki = 12 nM)- and low(Ki = 1010 nM)-affinity for pirenzepine in the coronary artery but predominantly low-affinity sites in cardiac muscle. AF-DX 116 and gallamine showed a lower affinity to (-)-[3H]QNB binding sites in the coronary artery compared to cardiac muscle. Thus, the present study suggests that porcine coronary artery contains a significant number of muscarinic receptors, probably both M1 and M2 subtypes.
Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
S
S
Yamada
T
T
Yamazawa
Y
Y
Harada
H I
HI
Yamamura
K
K
Nakayama
D000818:Animals; D003331:Coronary Vessels / Q000378:metabolism; D005260:Female; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D010276:Parasympatholytics / Q000494:pharmacology*; D011813:Quinuclidinyl Benzilate / Q000494:pharmacology; D011976:Receptors, Muscarinic / Q000378:metabolism*; D013552:Swine
D010276:Parasympatholytics; D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate