title: Links between Osmoregulation and Nitrogen-Excretion in Insects and Crustaceans.
abstract: The epithelia involved in ionoregulation and detoxification in crustaceans and insects are quite distinct: the gills, hepatopancreas, and antennal gland serve these functions in crustaceans, whereas the Malpighian tubules, hindgut, and, to some extent, the midgut, are involved in insects. This article compares the means by which the Na(+)/K(+)-ATPase and the vacuolar type H(+)-ATPase are used to energize ionoregulatory processes in both groups. The vacuolar H(+)-ATPase is particularly important as a generator of both H(+) gradients and transmembrane electrical gradients that can be used to energize electroneutral or electrogenic exchange of Na(+) and/or K(+) for H(+). In addition to cation:proton antiporters, epithelia in both groups depend upon the activity of Na(+):K(+):2Cl(-) cotransporters, Cl(-)/[Formula: see text] exchangers, and channels for K(+) and Cl(-) for transepithelial ion transport. This article also contrasts the dominant role of ammonia as the primary nitrogenous waste in crustaceans, with the excretion of ammonia, uric acid, or both in insects.
authors.affiliation: *Department of Biological Science, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba, Canada R3T 2N2.
authors.forename: Dirk
authors.initials: D
authors.lastname: Weihrauch
authors.affiliation: Department of Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1 odonnell@mcmaster.ca.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: O'Donnell
mesh_terms: D000641:Ammonia; D000818:Animals; D005075:Biological Evolution; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003445:Crustacea / Q000502:physiology*; D004573:Electrolytes; D005786:Gene Expression Regulation / Q000502:physiology; D005880:Gills / Q000378:metabolism; D007313:Insecta / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism*; D064587:Osmoregulation / Q000235:genetics / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D004573:Electrolytes; D000641:Ammonia; D009584:Nitrogen