title: Bile benzo[a]pyrene concentration and hepatic CYP1A induction in hypoxic adult tilapia (Oreochromis niloticus).
abstract: Aquatic hypoxia is a seasonal condition in some coastal and continental wetlands where co-exposure with polycyclic aromatic hydrocarbons (PAHs) pollution may be detrimental to the biota. In the present study, adult tilapia, an euryoxic fish of high economic importance, were intraperitoneally injected with benzo[a]pyrene (BaP) (20 mg kg(-1)) and then exposed to graded hypoxia to assess combined effects on some detoxification and fitness parameters. Seventy-two hours after a stepped decrease in dissolved oxygen (<2 mg L(-1)), BaP treatment resulted in a significant diminution on the biliary BaP concentration (70% of normoxic group) and an increase in blood glucose levels (2.17-fold compared with normoxic group). These effects returned to control values in the following 48 h of hypoxia exposure. BaP-induced CYP1A mRNA levels were unaffected by hypoxia, suggesting that reduced bile BaP concentration may be related with effects on protein amount or enzyme activities. LDH mRNA levels, blood lactate and hematocrit remained without change, suggesting no extreme detrimental effects for tilapia in the short-term of the BaP-hypoxia challenge. Our results indicate that BaP treatment and hypoxia targeted glucose metabolism and biliary BaP elimination, probably by favoring the storage of BaP in tilapia tissues.
authors.affiliation: Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Mérida, Mérida, Yucatán 97310, Mexico.
authors.forename: José Luis
authors.initials: JL
authors.lastname: García-Tavera
authors.forename: David
authors.initials: D
authors.lastname: Valdés-Lozano
authors.forename: Irais
authors.initials: I
authors.lastname: Poblete-Naredo
authors.forename: Arnulfo
authors.initials: A
authors.lastname: Albores-Medina
authors.forename: Omar
authors.initials: O
authors.lastname: Zapata-Pérez
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000737:chemistry / Q000633:toxicity*; D001646:Bile / Q000737:chemistry*; D001786:Blood Glucose / Q000032:analysis; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics / Q000378:metabolism*; D006400:Hematocrit; D000860:Hypoxia; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D019344:Lactic Acid / Q000097:blood; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017210:Tilapia / Q000378:metabolism*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D001786:Blood Glucose; D012333:RNA, Messenger; D014874:Water Pollutants, Chemical; D019344:Lactic Acid; D001564:Benzo(a)pyrene; D007770:L-Lactate Dehydrogenase; D019363:Cytochrome P-450 CYP1A1