Aufnahme von Fluorescein-markierter Hdroxyäthylstärke durch organgebundene und zirkulierende Zellen des retikuloendothelialen Systems

Abstract

Background: Intravenously administered hydroxyethyl starch (HES) is ingested and stored by organ-bound cells of the reticuloendothelial system (RES). Aim of the present study was to examine the transport mechanisms for HES between these organs of the RES. Material and Methods: Male Wistar rats were infused with 1 ml of a 1% fluorescein-labeled HES (FITC-HES). Before FITC-HES infusion, lymphocyte, granulocyte and monocyte clusters were identified by flow cytometry. Prior to as well as 180 and 360 min after FITC-HES infusion, blood samples were collected and cell-bound fluorescence was examined by flow cytometry. For histochemical examinations, animals which had received the same FITC-HES infusion were sacrificed 180 and 360 min after infusion. Results: The infusion of FITC-HES increased the cell-bound fluorescence expression in peripheral blood. The highest fluorescence intensities could be located in the monocyte cluster of the cytograms. Most of the cells with lower increases of fluorescence expression were polymorphonuclear granulocytes. In the lymphocyte cluster the fluorescence did not change. Splenic fluorescence appeared in the marginal-zone macrophages, where circular structures with high fluorescence intensities could be recognized. Additionally, we found intracellular fluorescence vesicles in Kupffer cells. Conclusions: The commonly suggested mechanism of the tissue storage of HES is a direct uptake of the intravascularly persisting colloid by sessile cells of the RES. The existence of clusters of circulating cells expressing significantly increased fluorescence intensities after infusion of a fluorescence-labeled HES indicates that a further cellular transport system does exist for HES.

Pharmacokinetics of Hydroxyethyl Starch (70/0.5) following Repeated Infusions

“…Nevertheless, other mechanisms besides glycosidase action are necessary to explain the increase of MS in the second urine sampling periods. Intracellular lysis after tissue storage especially in sessile or circulating cells of the reticuloendothelial system is another possibility [20]. Tissue storage of HES was also described in organs with effective immunological and detoxicating abilities like liver, spleen, or lung [8,21].…”

Acetylstärke als Volumenersatz, eine mögliche Alternative zu HES

“…Zeit ACS200/0,5 HES200/0,5 ACS200/0,5 HES200/0,5 ACS200/0,5 ACS200/0,5 (10) und kann dort über Jahre gespeichert werden (30) ohne zu einer Funktionseinschränkung zu führen (8,20,22,28). In Einzelfällen kann unter extremen Umständen die intensive Speicherung in den Hepatozyten eine reversible mechanische Beeinträchtigung der Leberfunktion auslösen (17,23).…”