Tyr8-Substance P Binding Study on a Plasma Membrane from Dog Ileum Smooth Muscle
Binding of 125I-Tyr8-substance P (125I-Tyr8-SP) to a plasma membrane enriched fraction (PM) from the circular muscle of canine small intestine was studied. The binding was fast, reversible and saturable with a KD and Bmax of 0.5 ± 0.06 nm and 742 ± 173 fmol/mg protein, respectively. 125Ieledoisin did not bind to PM. These results together with competition studies suggest that PH possesses SP-P receptors but not SP-E receptors.
KeywordsCircular Muscle Tachykinin Receptor Plasma Membrane Enzyme Circular Muscle Strip Canine Small Intestine
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