title: Calcium beta-hydroxy-beta-methylbutyrate. 1. Potential role as a phosphate binder in uremia: in vitro study.
abstract: The binding capacity of calcium beta-hydroxy-beta-methylbutyrate (calcium HMB), compared to other binders, was investigated in an in vitro study. Fifty milliequivalents of either calcium HMB, calcium acetate, calcium carbonate, aluminum hydroxide gel or non-gel aluminum hydroxide was added to a phosphate solution, titrated (HCl or NaOH), shaken and centrifuged to four different pH levels at 37 degrees C (simulating the gastrointestinal milieu). The difference in phosphate concentration between that of the initial and that of the supernatant represented from the bound phosphate in the precipitate. After 4 h at a pH of 6 (representing the intestinal condition after a meal), the binding percentage was: calcium acetate = 95.6%, calcium HMB = 92.6%, calcium carbonate = 46.4%, aluminum hydroxide gel = 33.4% and non-gel aluminum hydroxide = 17.8%. There was no significant difference (p > 0.05) between calcium HMB and calcium acetate. These results suggest that calcium HMB is an efficient phosphate binder in vitro, which may predict its effective role in vivo.
authors.affiliation: Department of Medicine, Evangelic School of Medicine, Curitiba, Brazil.
authors.forename: M F
authors.initials: MF
authors.lastname: Sousa
authors.forename: N N
authors.initials: NN
authors.lastname: Abumrad
authors.forename: C
authors.initials: C
authors.lastname: Martins
authors.forename: S
authors.initials: S
authors.lastname: Nissen
authors.forename: M C
authors.initials: MC
authors.lastname: Riella
mesh_terms: D000085:Acetates / Q000378:metabolism / Q000494:pharmacology; D000535:Aluminum / Q000378:metabolism / Q000494:pharmacology; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002119:Calcium Carbonate / Q000378:metabolism / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000378:metabolism; D013997:Time Factors; D014511:Uremia / Q000188:drug therapy* / Q000378:metabolism; D014631:Valerates / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000085:Acetates; D010710:Phosphates; D014631:Valerates; C004961:beta-hydroxyisovaleric acid; D000535:Aluminum; D002119:Calcium Carbonate; D002118:Calcium