Open AccessEffects of Deoxyribonuclease I and Neuraminidase Treatments on the Specific Binding of 3H-Prazosin and 3H-Quinuclidinyl Benzilate (3H-QNB) to α-Adrenergic and Muscarinic Receptors in Rat Myocardial Membranes
Author(s) -
Takafumi Nagatomo,
Hiroshi Tsuchihashi,
Shoichi Imai
Publication year - 1986
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.41.135
Subject(s) - quinuclidinyl benzilate , muscarinic acetylcholine receptor , neuraminidase , medicine , prazosin , endocrinology , receptor , dissociation constant , adrenergic receptor , sialic acid , biology , chemistry , biochemistry , enzyme , antagonist
The effects of neuraminidase and deoxyribonuclease I (DNase) treatments on the specific binding of 3H-prazosin and 3H-quinuclidinyl benzilate (3H-QNB) to alpha-adrenoceptors and muscarinic cholinergic receptors in the membrane of the rat myocardium was examined, and the dissociation constant (Kd) and the maximum number of binding sites (Bmax) was analyzed using the method of Scatchard analysis. Although no changes in Kd values were observed when DNA or sialic acid was removed from cardiac muscles by treatments with DNase or neuraminidase, the Bmax values of alpha-adrenergic and muscarinic receptors were markedly decreased after treatment with DNase, while neuraminidase treatment induced an increase in the Bmax values of the alpha-adrenoceptors. The possibility that these results provide the basis for elucidation of the characteristics of these receptors in the rat myocardium was discussed.