title: Absorption, kinetics, antibody-bound and free serum determination of a 14C-labeled Escherichia coli extract after single oral administration in rats.
abstract: The bioavailability of the major fraction of a 14C-labeled Escherichia coli extract (OM-89) of high molecular mass > 30 kD (HEC) was investigated in rats after a single oral administration of a dose of 100 mg/kg b.w. The determination of radioactivity in blood and plasma showed that HEC was absorbed by the digestive tract, either in its original form or partly degraded. In plasma, the radioactivity reached a Cmax value after 4 h, equivalent to an extract concentration of 31.7 micrograms/g of plasma with an elimination half live of 33 h. High molecular weight molecules of HEC (> 30 kD) were found by radiochromatography in rat serum 4 h after administration. Immunoprecipitation in the serum showed that HEC retains intact determinants throughout the digestive and absorptive processes. It is therefore absorbed either in its original form or partly degraded. A high incorporation of radiolabel was found in liver, secretory glands (adrenals, thyroid gland, pancreas), and in lymphoid organs (spleen, mesenteric lymph nodes).
authors.affiliation: Research & Consulting Company Umweltchemie AG, Department of Biochemistry, Itingen, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: van Dijk
authors.forename: J
authors.initials: J
authors.lastname: Bauer
authors.forename: E A
authors.initials: EA
authors.lastname: Sedelmeier
authors.forename: W G
authors.initials: WG
authors.lastname: Bessler
mesh_terms: D000276:Adjuvants, Immunologic / Q000493:pharmacokinetics*; D000818:Animals; D000942:Antigens, Bacterial; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000378:metabolism*; D005260:Female; D006207:Half-Life; D007408:Intestinal Absorption; D008297:Male; D011233:Precipitin Tests; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000276:Adjuvants, Immunologic; D000942:Antigens, Bacterial; C050501:OM 89