Binding characteristics of pancreatic polypeptide receptors on rat hepatic membranes.
OBJECTIVE
To study the binding characteristics of pancreatic polypeptide (PP) receptors on rat hepatic membranes.


METHODS
125I-PP suitable to study interaction between ligand and receptors were prepared. 125I-porcine PP and 125I-duck PP were used to study PP receptor binding in the controlled conditions.


RESULTS
The binding of 125I-porcine PP to receptors on rat hepatic membranes was time- and temperature-dependent. The specific binding of 125I-porcine PP was inhibited by unlabeled porcine PP in a concentration-dependent manner, whereas duck PP was only partially inhibited in the high concentration (> 500 nmol.L-1). Scatchard analysis produced a curvilinear plot, suggesting multiple affinity binding sites, i.e., high-affinity and low-affinity with dissociation constants (Kd) 5.4 and 158 nmol.L-1, respectively.


CONCLUSIONS
Rat hepatic membranes possessed specific PP receptors and porcine PP binding activity was much higher than that of duck PP.
Zhang
X T
XT
Shanghai Institute of Biochemistry, Chinese Academy of Sciences, China.
Yao
S Y
SY
Xu
Y G
YG
Zhu
S Q
SQ
D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D004372:Ducks; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure; D010179:Pancreas / Q000378:metabolism; D010191:Pancreatic Polypeptide / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011964:Receptors, Gastrointestinal Hormone / Q000302:isolation & purification / Q000378:metabolism*; D013045:Species Specificity; D013552:Swine
D011964:Receptors, Gastrointestinal Hormone; C029438:receptors, pancreatic polypeptide-specific; D010191:Pancreatic Polypeptide