Effect of diuretics on adrenergic receptors in the rat.
Diuretics have been reported to alter arteriolar smooth muscle responses to adrenergic stimulation as well as lymphocyte beta-adrenoceptor density. We have investigated the effect of four days treatment with hydrochlorothiazide or furosemide (10 mg/kg and day) injected subcutaneously in the rat on alpha 1-,alpha 2- and beta-adrenoceptors in different tissues. alpha 1-Adrenoceptor density and affinity in whole kidney and heart ventricle as determined by 3H-prazosin binding (in the absence and presence of 10(-5) M phentolamine) were unaltered by diuretic treatment, as were beta-adrenoceptor density and affinity in whole kidney, heart ventricle and skeletal muscle as determined by 125I-iodocyanopindolol binding (in the absence and presence of 10(-7) M (-)-propranolol). The density of alpha 2-adrenoceptors in particulate fraction from whole kidney homogenate as determined by 3H-rauwolscine binding was 12.8% higher in the hydrochlorothiazide-treated group (P less than 0.05) and 15.0% higher in the furosemide-treated group (P less than 0.01) than in the control group. The receptor affinity was similar in the different groups. Thus diuretic-induced alterations in adrenoceptors reported in previous studies were not observed in this study.
Brørs
O
O
Department of Pharmacology, University of Oslo, Norway.
Sandnes
D
D
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D004232:Diuretics / Q000494:pharmacology*; D005665:Furosemide / Q000494:pharmacology; D006321:Heart / Q000187:drug effects; D006852:Hydrochlorothiazide / Q000494:pharmacology; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects*
D004232:Diuretics; D007457:Iodine Radioisotopes; D011941:Receptors, Adrenergic; D006852:Hydrochlorothiazide; D005665:Furosemide