title: Small intestinal hydrolysis of plant glucosides: higher glucohydrolase activities in rodents than passerine birds.
abstract: Glycosides are a major group of plant secondary compounds characterized by one or more sugars conjugated to a lipophilic, possibly toxic aglycone, which is released upon hydrolysis. We compared small intestinal homogenate hydrolysis activity of three rodent and two avian species against four substrates: amygdalin and sinigrin, two plant-derived glucosides, the sugar lactose, whose hydrolysis models some activity against flavonoid and isoflavonoid glucosides, and the disaccharide sugar maltose (from starch), used as a comparator. Three new findings extend our understanding of physiological processing of plant glucosides: (1) the capacity of passerine birds to hydrolyze plant glucosides seems relatively low, compared with rodents; (2) in this first test of vertebrates' enzymic capacity to hydrolyze glucosinolates, sinigrin hydrolytic capacity seems low; (3) in laboratory mice, hydrolytic activity against lactose resides on the enterocytes' apical membrane facing the intestinal lumen, but activity against amygdalin seems to reside inside enterocytes.
authors.affiliation: Department of Forest and Wildlife Ecology, Russell Laboratories, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Krista M
authors.initials: KM
authors.lastname: Lessner
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: M Denise
authors.initials: MD
authors.lastname: Dearing
authors.affiliation: Department of Evolutionary and Environmental Biology, University of Haifa, Haifa 31905, Israel.
authors.forename: Ido
authors.initials: I
authors.lastname: Izhaki
authors.affiliation: Department of Biology, Technion, Haifa 32000, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Samuni-Blank
authors.affiliation: Department of Biology, Technion, Haifa 32000, Israel.
authors.forename: Zeev
authors.initials: Z
authors.lastname: Arad
authors.affiliation: Department of Forest and Wildlife Ecology, Russell Laboratories, University of Wisconsin-Madison, Madison, WI 53706, USA wkarasov@wisc.edu.
authors.forename: William H
authors.initials: WH
authors.lastname: Karasov
mesh_terms: D000678:Amygdalin / Q000378:metabolism; D000818:Animals; D020895:Enterocytes / Q000378:metabolism; D005960:Glucosides / Q000378:metabolism*; D005961:Glucosinolates / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006868:Hydrolysis; D007421:Intestine, Small / Q000378:metabolism*; D010694:Lactase-Phlorizin Hydrolase / Q000378:metabolism; D007785:Lactose / Q000378:metabolism; D008320:Maltose / Q000378:metabolism; D051189:Murinae / Q000378:metabolism*; D046109:Passeriformes / Q000378:metabolism*; D013045:Species Specificity; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D005960:Glucosides; D005961:Glucosinolates; D000678:Amygdalin; C010330:sinigrin; D008320:Maltose; D006026:Glycoside Hydrolases; D001617:beta-Glucosidase; D010694:Lactase-Phlorizin Hydrolase; D007785:Lactose
keywords: Cytosolic β-glucosidase; Digestion; Enzyme; Lactase phlorizin hydrolase; Plant secondary compounds