Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0393754 (HSA)
 2,996 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Propranolol binding to human albumin (HSA) and to mixtures of alpha 1-acid glycoprotein (AGP) and HSA was examined in the presence of a perfluorochemical (PFC) blood substitute. The per cent free propranolol was determined using a dialysis exchange method at 37 degrees C. In 4% HSA solutions the per cent free propranolol was 51.9% and 53.6% at propranolol concentrations of 100 and 500 ng/ml, respectively. Buffer dilutions of 4% HSA solutions resulted in an increase in free propranolol. However, dilution of the HSA solutions with the PFC emulsion resulted in a significant decrease in free propranolol. In solutions containing 4% HSA with 0.067% AGP, the per cent free propranolol was 22.6% and 23.5% for 100 and 500 ng/ml propranolol, respectively. Again, the per cent free propranolol increased upon plasma protein dilution with buffer solution and decreased upon dilution with the blood substitute. A centrifugation method was utilized to determine the per cent bound propranolol associated with the PFC emulsion droplets in the presence of the proteins. Propranolol was significantly bound by the PFC emulsion even in the presence of a mixture of AGP and HSA. These results indicate that the overall affinity of the PFC blood substitute for propranolol is very substantial. Thus, administration of this PFC blood substitute may not result in the significant increase in per cent free propranolol normally associated with plasma protein dilution.
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PMID:Human albumin and alpha 1-acid glycoprotein binding of propranolol in the presence of a perfluorochemical blood substitute. 273 Feb 40

Propranolol binding to isolated human alpha-1-acid glycoprotein (AGP) and human albumin (HSA) was studied by equilibrium dialysis at 37 degrees C. With AGP (0.067%) and HSA (4%), total propranolol concentration was varied from 0.7 to 93,000 ng mL-1. Over this concentration range the percentage drug bound to HSA declined from 49 to 39% while that to AGP declined from 68 to 4%. Two classes of sites were identified on AGP with n1k1 = 8.50 X 10(4) M-1 and n2k2 = 3.12 X 10(4) M-1. With a pH 7.4 phosphate buffer, propranolol binding to AGP was greatest when the protein was initially dissolved in pH 7.4 water compared with pH 7.2 water or the phosphate buffer. Thus, the method of AGP solution preparation affected propranolol binding by this protein. For both AGP and HSA, greater drug binding was noted with phosphate buffers in comparison with a physiological buffer. With phosphate buffers, decreasing pH from 7.4 to 7.0 decreased propranolol binding by AGP, while decreasing pH from 7.7 to 7.4 had little effect. With HSA, the percent propranolol bound consistently decreased on lowering pH from 7.7 to 7.0.
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PMID:Buffer and pH effects on propranolol binding by human albumin and alpha 1-acid glycoprotein. 290 83