Premium
The binding of [ 3 H]‐tiotidine to homogenates of guinea‐pig lung parenchyma
Author(s) -
Foreman J.C.,
Norris D.B.,
Rising T.J.,
Webber S.E.
Publication year - 1985
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1985.tb08917.x
Subject(s) - guinea pig , parenchyma , dissociation constant , receptor , agonist , lung , dissociation rate , biology , dissociation (chemistry) , medicine , endocrinology , chemistry , biochemistry , botany
1 By use of a rapid filtration assay, the binding of [ 3 H]‐tiotidine to homogenates of guinea‐pig lung parenchyma was found to be saturable and of a high affinity. Mean values for the K D and B max were calculated as 8.5 ± 1.5 nM and 28 ± 5 fmol mg −1 protein respectively. 2 The association and dissociation rate constants for [ 3 H]‐tiotidine binding at 4°C were calculated to be 0.81 ± 0.06 μM min −1 and 0.063 ± 0.005 min −1 respectively, yielding a kinetically derived K D of 7.8 nM. 3 A wide range of H 2 ‐receptor agonist and antagonists displaced [ 3 H]‐tiotidine binding from lung parenchyma homogenates in a biphasic manner. 4 Examination of the first phase of the displacement of [ 3 H]‐tiotidine yielded K i values for the antagonists tested similar to those found in other binding studies using this ligand and similar to K B values calculated for the antagonists in pharmacological studies.