Binding sites for [125I]-Bolton-Hunter scyliorhinin II in guinea-pig ileum: a radioligand binding, functional and autoradiographic study

1994 ◽  
Vol 350 (3) ◽  
Author(s):  
ChristianJ. Mussap ◽  
Elizabeth Burcher
Keyword(s):  
Guinea Pig ◽  
Binding Sites ◽  
Radioligand Binding ◽  
Autoradiographic Study ◽  
Guinea Pig Ileum

Binding sites for [3H][Sar9, Met(O2)11]substance P in rat bain and guinea pig ileum

1991 ◽  
Vol 560 (1-2) ◽  
pp. 1-11 ◽  
Author(s):  
Christine Tousignant ◽  
Gaétan Guillemette ◽  
Domenico Regoli
Keyword(s):  
Substance P ◽  
Guinea Pig ◽  
Binding Sites ◽  
Guinea Pig Ileum

Characterization of kinin binding sites: identity of B2 receptors in the epithelium and the smooth muscle of the guinea pig ileum

1991 ◽  
Vol 69 (6) ◽  
pp. 818-825 ◽  
Author(s):  
C. Tousignant ◽  
G. Guillemette ◽  
J. Barabé ◽  
N.-E. Rhaleb ◽  
D. Regoli
Keyword(s):  
Smooth Muscle ◽  
Epithelial Cell ◽  
Guinea Pig ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Binding Sites ◽  
Cell Membranes ◽  
Specific Binding ◽  
Scatchard Analysis ◽  
Guinea Pig Ileum

Binding of [125I-Tyr8]bradykinin (BK) was measured in homogenates of epithelial and smooth muscle layers of the guinea pig ileum. Binding assays were performed at 4 °C for 40 min (smooth muscle) or 90 min (epithelium) in 25 mM PIPES buffer at pH 6.8 in the presence of 1 mM 1,10-phenanthroline, 140 μg/mL bacitracin, 1 mM captopril, 1 mM dithiothreitol, and 0.1% bovine serum albumin. Specific binding of [125I-Tyr8]BK (0.32 nM) to epithelial and smooth muscle cell membranes was linearly related to protein concentration between 0.05 and 0.5 mg/mL. Equilibrium experiments showed that specific binding of [125I-Tyr8]BK was saturable and Scatchard analysis indicated the presence of a high affinity site with a Kd value of 1.6 nM and a Bmax. of 156 fmol/mg of protein in the epithelial cell membranes. In smooth muscle membranes, Kd was 1.8 nM and the maximum number of binding sites was 58 fmol/mg of protein. Unlabelled peptides, namely bradykinin, [Tyr8]BK, [Hyp3]BK, D-Arg[Hyp3]BK, [Hyp3,Tyr(Me8)]BK, and kallidin displaced [125I-Tyr8]BK binding while other peptides, angiotensin II and substance P, had no effect. A series of B2-receptor antagonists displaced [125I-Tyr8]BK from specific binding sites with IC50 values ranging from 16 to 152 nM on epithelial cell membranes; similar values were obtained from smooth muscle cell membranes. These findings suggest that the binding sites in both preparations are of the B2 type. B1-receptor agonists and antagonists were found to be inactive at concentrations up to 10−4 M. Results obtained in the two preparations were compared and a positive highly significant correlation was demonstrated between the two sets of data. It is therefore concluded that B2 receptors found in the epithelium and the smooth muscle membranes of the guinea pig ileum are identical. These sites are similar to the functional receptor mediating the myotropic effect of bradykinin in the ileum.Key words: kinins, epithelium, smooth muscle, guinea pig ileum, binding and biological assays.

A comparative autoradiographic study of 5-HT1D binding sites in human and guinea-pig brain using different radioligands

1994 ◽  
Vol 21 (1-2) ◽  
pp. 19-29 ◽  
Author(s):  
Anne T. Bruinvels ◽  
Bernhard Landwehrmeyer ◽  
Alphonse Probst ◽  
JoséM. Palacios ◽  
Daniel Hoyer
Keyword(s):  
Guinea Pig ◽  
Binding Sites ◽  
Autoradiographic Study ◽  
Pig Brain ◽  
Guinea Pig Brain

Ischemia- and agonist-induced changes in alpha- and beta-adrenergic receptor traffic in guinea pig hearts

1987 ◽  
Vol 253 (5) ◽  
pp. H1159-H1166 ◽  
Author(s):  
A. S. Maisel ◽  
H. J. Motulsky ◽  
M. G. Ziegler ◽  
P. A. Insel
Keyword(s):  
Guinea Pig ◽  
Binding Sites ◽  
Adrenergic Receptors ◽  
Adrenergic Receptor ◽  
Radioligand Binding ◽  
Subcellular Fractionation ◽  
Beta Adrenergic Receptors ◽  
Beta Adrenergic ◽  
Beta Receptors ◽  
Induced Changes

We have used radioligand binding techniques and subcellular fractionation to assess whether changes in expression of myocardial alpha 1- and beta-adrenergic receptors are mediated by a redistribution of receptors between various membrane fractions. Three fractions were prepared from the left ventricles of guinea pigs that underwent either 1 h of ischemia or injection of epinephrine (0.25 mg/kg ip): a crude membrane, a purified sarcolemma, and a light vesicle fraction. In control animals alpha 1-adrenergic receptors ([3H]prazosin binding) in light vesicles was only 25% of the total alpha 1-receptor density found in sarcolemmal and light vesicle fractions as compared with 50% for beta-adrenergic receptors ([125I]iodocyanopindolol binding sites). Although ischemia was associated with a 53% decrease in the number of light vesicle beta-adrenergic receptors and a 42% increase in the number of sarcolemma beta-receptors (P less than 0.05), there was no change in the number of light vesicle alpha 1-receptors, even though the number of sarcolemmal alpha 1-receptors increased 34%. Epinephrine treatment promoted internalization of beta-adrenergic receptors; sarcolemma beta-receptors decreased 37% and light vesicle beta-receptors increased 28% (P less than 0.025). For alpha 1-receptors, epinephrine treatment decreased the number of sarcolemmal receptors 41% (P less than 0.025) but failed to increase the number of receptors in the light vesicle fraction. The changes in receptor binding to beta-adrenergic receptors in sarcolemmal fractions were mirrored by parallel changes in isoproterenol-stimulated adenylate cyclase activity. These results indicate that alpha 1- and beta-adrenergic receptors may undergo a different cellular itinerary in guinea pig myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)

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