In vitro binding of dantrolene to bovine serum albumin and rabbit red blood cell ghosts.
The binding of dantrolene to rabbit red blood cell (RBC) ghosts and bovine serum albumin as models of receptor sites was studied using fluorescence techniques. Dantrolene upon binding to rabbit RBC ghosts and bovine serum albumin showed fluorescence with emission maxima at 495 and 500 nm, respectively. Dantrolene bound to rabbit RBC ghosts with an association constant of 6.06 X 10(4) M-1 and there were 2.4 X 10(6) dantrolene binding sites per ghost. The binding of dantrolene to bovine serum albumin showed an anomaly with respect to dantrolene concentration. Dantrolene at concentrations of 1.25-3.75 microM bound to bovine serum albumin with an association constant of 1.72 X 10(4) M-1 and there were 1.078 binding sites/mol bovine serum albumin. The higher affinity of dantrolene toward blood cells was confirmed by studying the distribution of dantrolene between blood cells and plasma after a single i.p. injection of dantrolene sodium (3 mg/kg) to albino rabbits. It was found that the concentration of dantrolene in rabbit blood cells was 2.76 times that of plasma.
D000818:Animals; D001667:Binding, Competitive; D002417:Cattle; D003620:Dantrolene / Q000097:blood*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D011485:Protein Binding; D011817:Rabbits; D012710:Serum Albumin, Bovine / Q000378:metabolism; D014700:Verapamil / Q000494:pharmacology
D012710:Serum Albumin, Bovine; D014700:Verapamil; D003620:Dantrolene