title: Increased production and excretion of urea in the kuruma shrimp (Marsupenaeus japonicus) exposed to combined environments of increased ammonia and nitrite.
abstract: Marsupenaeus japonicus (6.37 +/- 1.29 g) individually exposed to 9 different combined solutions of ambient ammonia (C) and nitrite (C') ammonia at 0.003 [control], 0.39, and 1.49 mmol/L combined with nitrite at 0.001 [control], 0.38, and 1.49 mmol/L in 30 ppt were examined for nitrogenous excretion accumulations of ammonia, nitrite, urea, and uric acid in tissues after 48 hours. M. japonicus exposed to 0.39 mmol/L ammonia-0.38 mmol/L nitrite displayed higher levels of urea-nitrogen (UNE) and organic-N (ONE) excretion by a factor of 2.2 and 5.7, respectively, compared with shrimp exposed only to 0.39 mmol/L ammonia. Exposure to 0.39 mmol/L ammonia-0.38 mmol/L nitrite resulted in lower levels of hemolymph uric acid (HUA), gill ammonia (GAM), gill urea (GUE), gill uric acid (GUA), hepatopancreas ammonia (HPAM), hepatopancreas urea (HPUE), and hepatopancreas uric acid (APUA), respectively, compared with shrimp exposed only to 0.39 mmol/L ammonia. We concluded that M. japonicus exposed to combined environments of ammonia and nitrite display increased nitrogen metabolism and production of urea-N and other organic-N.
authors.affiliation: Department of Aquaculture, College of Life and Resources Sciences, National Taiwan Ocean University, Keelung, Taiwan, 202, China.
authors.forename: S-Y
authors.initials: SY
authors.lastname: Cheng
authors.forename: W C
authors.initials: WC
authors.lastname: Lee
authors.forename: L W
authors.initials: LW
authors.lastname: Shieh
authors.forename: J-C
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000641:Ammonia / Q000633:toxicity*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure; D005880:Gills / Q000502:physiology; D043143:Hepatopancreas / Q000502:physiology; D009573:Nitrites / Q000633:toxicity*; D009584:Nitrogen / Q000378:metabolism*; D033561:Penaeidae / Q000502:physiology*; D014508:Urea / Q000493:pharmacokinetics*; D014873:Water Pollutants / Q000633:toxicity*
chemical_list: D009573:Nitrites; D014873:Water Pollutants; D000641:Ammonia; D014508:Urea; D009584:Nitrogen