Meeting Abstract

98.3  Monday, Jan. 6 14:00  Mechanistic correlates of paracellular nutrient absorption in protein specialists PRICE, E.R.*; CAVIEDES-VIDAL, E.; KARASOV, W.H.; University of Wisconsin-Madison; Universidad Nacional de San Luis; University of Wisconsin-Madison eprice2@wisc.edu

Water-soluble nutrients (e.g., glucose and amino acids) can be absorbed across enterocytes via protein-mediated transport, or paracellularly through the tight junctions between enterocytes. Previously we demonstrated that absorption of arabinose (a nutrient-sized paracellular probe) was higher in intact insectivorous bats (Tadarida brasiliensis and Myotis lucifugus) when compared to insectivorous rodents (Onychomys leucogaster and Peromyscus leucopus). This phenomenon can also be observed in isolated intestines: in intestinal perfusions, arabinose clearance was higher in insectivorous bats compared to insectivorous rodents when compared on a nominal surface area basis. This implies that bats have either more tight junctions per nominal surface area (for example via longer villi) and/or bats have leakier tight junctions (perhaps achieved via differential expression of the proteins that form the tight junctions). We investigated these mechanistic correlates using histological examination of intestines and by measuring gene expression of several claudin proteins. Supported by NSF Award 1025886.