In the present study equilibrium dialysis has been used to determine the degree of protein binding of the catecholamines adrenaline and noradrenalin and the adrenergic receptor blockers, prazosin and propranolol in diabetics.
The binding of the catecholamines in plasma from Type I and II diabetic patients was not significantly different from that of healthy subjects. The ratio of the bound and free catecholamine concentrations was correlated with the level of albumin (HSA).
Significantly reduced protein binding of prazosin was observed in Type I and II diabetic subjects compared to healthy volunteers. The binding of propranolol was significantly reduced in Type I patients.
The ratios between the bound and unbound concentrations of prazosin and propranolol were significantly correlated with the levels of a,-acid glycoprotein (AAG). The results suggest that non-enzymatic glycosylation of plasma proteins may increase the unbound fraction of the adrenergic blockers prazosin and propranolol.
Diabetes mellitus Drug protein binding Catecholamines adrenoceptor blockers prazosin propranolol
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Ruiz-Cabello F, Erill S (1984) Abnormal serum protein bindingof acidic drugs in diabetes mellitus. Clin Pharmacol Ther 36: 691–695PubMedGoogle Scholar
Barry MG, Collins WCJ, Feely J (1986) Plasma protein binding of drugs in insulin dependent diabetes mellitus. Br J Pharmaco 189: 719pGoogle Scholar
Sager G (1990) Types ofβ-adrenergic binding sites on plasma proteins and blood cells. In: Belpaire F, Bogaert M, Tillement JP, Verbeeck R (eds) Plasma binding of drugs and its consequences. Academia Press, Ghent, pp 43–53Google Scholar
Rubin P, Blaschke T (1980) Prazosin protein binding in health and disease. Br J Clin Pharmacol 9: 177–182PubMedGoogle Scholar
Dale O, Nilsen OG (1984) Differences in the serum protein binding of prazosin in man and rat. Biochem Pharmacol 33: 1719–1724CrossRefPubMedGoogle Scholar
Brunner F, Muller WE (1985) Prazosin binding to human α1-acid glycoprotein (orosomucoid), human serum albumin, and human serum. Further characterization of the „single drug binding site” of orosomucoid. J Pharm Pharmacol 37: 305–309PubMedGoogle Scholar
Sager G, Jæger R, Little C (1989) Binding of prazosin to α1-acid glycoprotein and albumin: effect of protein purity and concentrations. Pharmacol Toxicol 64: 365–368PubMedGoogle Scholar
Sager G, Bratlid H, Little C (1987) Binding of catecholamines to alpha-1 acid glycoprotein, albumin, and lipoproteins in human serum. Biochem Pharmacol 36: 3607–3612CrossRefPubMedGoogle Scholar