title: Intestinal paracellular absorption is necessary to support the sugar oxidation cascade in nectarivorous bats.
abstract: We made the first measurements of the capacity for paracellular nutrient absorption in intact nectarivorous bats. Leptonycteris yerbabuenae (20 g mass) were injected with or fed inert carbohydrate probes L-rhamnose and D(+)-cellobiose, which are absorbed exclusively by the paracellular route, and 3-O-methyl-D-glucose (3OMD-glucose), which is absorbed both paracellularly and transcellularly. Using a standard pharmacokinetic technique, we collected blood samples for 2 h after probe administration. As predicted, fractional absorption (f) of paracellular probes declined with increasing Mr in the order of rhamnose (f=0.71)>cellobiose (f=0.23). Absorption of 3OMD-glucose was complete (f=0.85; not different from unity). Integrating our data with those for glucose absorption and oxidation in another nectarivorous bat, we conclude that passive paracellular absorption of glucose is extensive in nectarivorous bat species, as in other bats and small birds, and necessary to support high glucose fluxes hypothesized for the sugar oxidation cascade.
authors.affiliation: Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA Centro de Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala de Xicohténcatl 90062, México.
authors.forename: Nelly
authors.initials: N
authors.lastname: Rodriguez-Peña
authors.affiliation: Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Edwin R
authors.initials: ER
authors.lastname: Price
authors.affiliation: Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA Laboratorio de Biología Integrativa, Instituto Multidisciplinario de Investigaciones Biológicas de San Luis, Consejo Nacional de Investigaciones Científicas y Técnicas, and Departamento de Bioquímica y Ciencias Biológicas, Universidad Nacional de San Luis, San Luis 5700, Argentina.
authors.forename: Enrique
authors.initials: E
authors.lastname: Caviedes-Vidal
authors.affiliation: Laboratorio de Fisiología Vegetal, UBIPRO, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autonoma de México, Tlalnepantla, Estado de Mexico, C.P. 54090, México.
authors.forename: Cesar M
authors.initials: CM
authors.lastname: Flores-Ortiz
authors.affiliation: Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA wkarasov@wisc.edu.
authors.forename: William H
authors.initials: WH
authors.lastname: Karasov
mesh_terms: D019325:3-O-Methylglucose / Q000008:administration & dosage / Q000493:pharmacokinetics; D000818:Animals; D002475:Cellobiose / Q000008:administration & dosage / Q000493:pharmacokinetics; D002685:Chiroptera / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D007408:Intestinal Absorption; D008297:Male; D010084:Oxidation-Reduction; D012210:Rhamnose / Q000008:administration & dosage / Q000493:pharmacokinetics
chemical_list: D019325:3-O-Methylglucose; D002475:Cellobiose; D005947:Glucose; D012210:Rhamnose
keywords: 3-O-methyl-d-glucose; Bioavailability; Intestine; Leptonycteris yerbabuenae; Nutrient absorption; Sugars; d-Cellobiose; l-Rhamnose