title: Widespread Natural Occurrence of Hydroxyurea in Animals.
abstract: Here we report the widespread natural occurrence of a known antibiotic and antineoplastic compound, hydroxyurea in animals from many taxonomic groups. Hydroxyurea occurs in all the organisms we have examined including invertebrates (molluscs and crustaceans), fishes from several major groups, amphibians and mammals. The species with highest concentrations was an elasmobranch (sharks, skates and rays), the little skate Leucoraja erinacea with levels up to 250 μM, high enough to have antiviral, antimicrobial and antineoplastic effects based on in vitro studies. Embryos of L. erinacea showed increasing levels of hydroxyurea with development, indicating the capacity for hydroxyurea synthesis. Certain tissues of other organisms (e.g. skin of the frog (64 μM), intestine of lobster (138 μM) gills of the surf clam (100 μM)) had levels high enough to have antiviral effects based on in vitro studies. Hydroxyurea is widely used clinically in the treatment of certain human cancers, sickle cell anemia, psoriasis, myeloproliferative diseases, and has been investigated as a potential treatment of HIV infection and its presence at high levels in tissues of elasmobranchs and other organisms suggests a novel mechanism for fighting disease that may explain the disease resistance of some groups. In light of the known production of nitric oxide from exogenously applied hydroxyurea, endogenous hydoxyurea may play a hitherto unknown role in nitric oxide dynamics.
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: David I
authors.initials: DI
authors.lastname: Fraser
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Kyle T
authors.initials: KT
authors.lastname: Liu
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Reid
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Emily
authors.initials: E
authors.lastname: Hawkins
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Sevier
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Pyle
authors.affiliation: Durham College, Oshawa, Ontario, Canada.
authors.forename: Jacob W
authors.initials: JW
authors.lastname: Robinson
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Pierre H R
authors.initials: PH
authors.lastname: Ouellette
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: James S
authors.initials: JS
authors.lastname: Ballantyne
mesh_terms: D000755:Anemia, Sickle Cell / Q000188:drug therapy; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D003445:Crustacea / Q000378:metabolism; D015658:HIV Infections / Q000188:drug therapy; D006801:Humans; D006918:Hydroxyurea / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D008974:Mollusca / Q000378:metabolism; D012754:Sharks / Q000378:metabolism; D012860:Skates, Fish / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D006918:Hydroxyurea