Interactions of bambuterol with human serum cholinesterase of the genotypes EuEu (normal), EaEa (atypical) and EuEa.

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Tunek A, Hjertberg E, Mogensen JV

Interactions of bambuterol with human serum cholinesterase of the genotypes EuEu (normal), EaEa (atypical) and EuEa.

Biochem Pharmacol. 1991 Feb 1;41(3):345-8. doi: 10.1016/0006-2952(91)90530-i.

PubMed ID

1994894 [ View in PubMed

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Abstract

Bambuterol, a carbamate ester prodrug of the bronchodilator terbutaline, was tested as inhibitor and substrate of human serum cholinesterases of the genotypes EuEu (the normal enzyme), EaEa (the atypical enzyme) and EuEa. The IC50 for the normal enzyme was 11 +/- 2.2 nM (mean, SD, N = 10) and for the atypical enzyme 140 +/- 6 nM (N = 13), indicating a much higher affinity of bambuterol to the normal enzyme. The heterozygotes showed a mixed behaviour; the major activity was inhibited like the normal enzyme (IC50 = 9.3 +/- 1.9 nM, N = 9), while a residual activity (10-15%) was inhibited by bambuterol like the atypical enzyme. At a bambuterol concentration of 100 nM each of the three cholinesterase genotypes responded uniquely to bambuterol; the normal enzyme was inhibited to 2.2 +/- 0.9%, the atypical enzyme to 58 +/- 4.6%, and the heterozygote to 10 +/- 1.2% of the basal activity. Bambuterol may therefore be added to the list of inhibitors useful in the genotyping of cholinesterases. Bambuterol was much less efficiently hydrolysed in serum containing the atypical cholinesterase than in serum containing the normal enzyme. The results of the hydrolysis experiments once again illustrate the difference in affinity of bambuterol to the genetic forms of cholinesterase, and also strengthen the evidence that cholinesterase is the major serum enzyme catalysing the hydrolysis of bambuterol.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Bambuterol	Cholinesterase	Protein	Humans	Unknown	Inhibitor	Details

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Bambuterol	Cholinesterase	Protein	Humans	Unknown	Substrate Inhibitor	Details