Next Article in Journal
Hydrogeochemistry and Precursory Anomalies in Thermal Springs of Fujian (Southeastern China) Associated with Earthquakes in the Taiwan Strait
Next Article in Special Issue
Differential Molecular Responses of Zebrafish Larvae to Fluoxetine and Norfluoxetine
Previous Article in Journal
Organic Pollutants Removal from Olive Mill Wastewater Using Electrocoagulation Process via Central Composite Design (CCD)
Previous Article in Special Issue
Meeting the Salinity Requirements of the Bivalve Mollusc Crassostrea gigas in the Depuration Process and Posterior Shelf-Life Period to Improve Food Safety and Product Quality
Article

Urea Excretion and Arginase Activity as New Biomarkers for Nitrite Stress in Freshwater Aquatic Animals

1
Dipartimento di Scienze e Tecnologie, Università degli Studi di Napoli Parthenope, Via Acton n. 38, I-80133 Napoli, Italy
2
Dipartimento di Biologia, Università di Napoli Federico II, Complesso Universitario Monte Sant’Angelo, Via Cinthia, I-80126 Napoli, Italy
*
Author to whom correspondence should be addressed.
Academic Editors: Laura Guimarães and Carlos Gravato
Water 2021, 13(24), 3521; https://doi.org/10.3390/w13243521
Received: 28 October 2021 / Revised: 5 December 2021 / Accepted: 6 December 2021 / Published: 9 December 2021
Background: In recent years, the concern has been growing on increasing aquatic nitrite levels due to anthropogenic activities. Crustaceans and fish easily uptake nitrite via the chloride uptake system of gills. High nitrite body levels may interfere with nitric oxide (NO) production by nitric oxide synthase (NOS). The arginase, which catalyzes arginine conversion to ornithine and urea, is central to NO homeostasis. In vivo, changes in the arginase activity alter urea body levels and urea excretion and modulate NOS by altering arginine availability for NO synthesis. Excess arginase activity may uncouple NOS and induce oxidative stress. Methods: We tested muscle arginase activity and urea excretion in two fish species, zebrafish and convict cichlid, and the crustacean Yamato shrimp, under sub-lethal nitrite stress. Results: Exposure to nitrite (2 mM in the fish, 1 mM in the shrimp) significantly increased blood nitrite concentration in all species. Concomitantly, nitrite stress significantly increased arginase activity, urea excretion, and urea levels in the blood. In Yamato shrimp, urea levels also increased in muscle. Conclusion: Our results agree with the hypothesis that nitrite stress affects NO homeostasis by arginase stimulation and urea excretion. These parameters might function as markers of sub-lethal nitrite stress in freshwater fish and crustaceans. View Full-Text
Keywords: nitrite; arginase; nitric oxide; nitric oxide synthase; urea excretion; Danio rerio; Amatitlania nigrofasciata; Caridina multidentata nitrite; arginase; nitric oxide; nitric oxide synthase; urea excretion; Danio rerio; Amatitlania nigrofasciata; Caridina multidentata
Show Figures

Graphical abstract

MDPI and ACS Style

Napolitano, G.; Fasciolo, G.; Agnisola, C.; Venditti, P. Urea Excretion and Arginase Activity as New Biomarkers for Nitrite Stress in Freshwater Aquatic Animals. Water 2021, 13, 3521. https://doi.org/10.3390/w13243521

AMA Style

Napolitano G, Fasciolo G, Agnisola C, Venditti P. Urea Excretion and Arginase Activity as New Biomarkers for Nitrite Stress in Freshwater Aquatic Animals. Water. 2021; 13(24):3521. https://doi.org/10.3390/w13243521

Chicago/Turabian Style

Napolitano, Gaetana, Gianluca Fasciolo, Claudio Agnisola, and Paola Venditti. 2021. "Urea Excretion and Arginase Activity as New Biomarkers for Nitrite Stress in Freshwater Aquatic Animals" Water 13, no. 24: 3521. https://doi.org/10.3390/w13243521

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop