title: Physical plugging does not account for attenuation of capillary leakage by hydroxyethyl starch 130/0.4: a synthetic gel layer model.
abstract: Hydroxyethyl starch (HES) solutions, widely used plasma substitutes, reportedly attenuate capillary leakage via physical plugging of capillary defects. We investigated how 2% HES solutions of different molecular weights (HES(70): 70 kDa, HES(130): 130 kDa, HES(200): 200 kDa, and HES(670): 670 kDa) affect dye release from polyacrylamide gels (PAGs) as a model of endothelial glycocalyx. We assessed dye release from 4% PAG with varying concentrations of albumin [0, 1, 2, 4, and 8% (w/v)] by measuring the change in dye absorbance (ΔAbs) at 5 h for each HES solution. For PAG containing no albumin, ΔAbs for HES(130) was 30% lower than that for HES(70) and HES(200), and 50% lower than that for HES(670). At concentrations of 1-8% albumin, ΔAbs at 5 h with HES(70), HES(130), and HES(200) solutions were almost half that with the HES(670) solution, but no significant differences were noted in ΔAbs at 5 h among HES(70), HES(130), and HES(200) solutions. The inhibition of dye release by HES(670) is likely due to the hindering effect of HES molecules partitioned into gel pores. However, a unique property of HES(130) , including the heavy hydroxyethylation at the C(2) position, may promote specific interactions with PAG and thereby inhibit solute release.
authors.affiliation: Department of Anesthesiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan. ttatara@hyo-med.ac.jp
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Tatara
authors.forename: Motoi
authors.initials: M
authors.lastname: Itani
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugi
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Fujita
mesh_terms: D002196:Capillaries / Q000187:drug effects*; D002199:Capillary Permeability / Q000187:drug effects*; D005782:Gels; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*
chemical_list: D005782:Gels; D006895:Hydroxyethyl Starch Derivatives