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STUDIES OF INTESTINAL AND FÆCAL SUBSTANCES FROM GERMFREE RATS INHIBITING BACTERICIDAL ACTIVITY OF RAT SERUM
Author(s) -
Winsnes Randi,
Trippestad Arne,
Midtvedt Tore,
Wold Jens K.
Publication year - 1973
Publication title -
acta pathologica microbiologica scandinavica section b microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0365-5563
DOI - 10.1111/j.1699-0463.1973.tb00216.x
Subject(s) - fucose , hydrolysate , pronase , polysaccharide , sialic acid , chemistry , biochemistry , intestinal mucosa , hydrolysis , proteolysis , glycoprotein , in vitro , fructose , chromatography , trypsin , enzyme , medicine
Evidence that extracts of intestinal contents and intestinal mucosa from germfree rats fed a defined diet, inhibit the bactericidal activity of rat serum on E.coli is presented and a partial chemical characterization of the active factor, FIB, is given. FIB was present in an aqueous extract of intestinal mucosa and fœees and was non‐dialysable. Extraction with chloroform—methanol (4:1, by vol.) followed by acetone did not reduce the activity of FIB, indicating that lipids were not necessary for effect. The inhibiting factor resisted 100° C for 30 min. FIB was also resistant to proteolysis (pronase) for 8 days, and was recovered in the resulting non‐dialysable hydrolysate, whereas the dialysable fraction was inactive. Thiol‐blocking agents had no effect on FIB activity, indicating that the factor was not dependent upon intact thiol groups. FIB activity was enhanced by weak acid hydrolysis, causing liberation of sialic acid and fucose. These observations suggest that FIB is either of polysaccharide or glycoprotein nature. A general inhibition of the bactericidal activity of serum exerted by polar high molecular substances was unlikely, since this effect could neither be demonstrated for the plant polysaccharides nor for the bovine glycoprotein fraction tested.