Data/hora: 01/06/2024 02:20:06

Provedor de dados: 	83	
País: 	Brazil	
Título: 	NTPDase and acetylcholinesterase activities in silver catfish, Rhamdia quelen (Quoy &amp;amp; Gaimard, 1824) (Heptapteridae) exposed to interaction of oxygen and ammonia levels	
Autores: 	Kaizer,Rosilene Rodrigues; Loro,Vania Lúcia; Schetinger,Maria Rosa Chitolina; Morsch,Vera Maria; Tabaldi,Luciane Almeri; Rosa,Cíntia Saydelles da; Garcia,Luciano de Oliveira; Becker,Alexssandro G.; Baldisserotto,Bernardo.	
Data: 	2009-01-01	
Ano: 	2009	
Palavras-chave: 	Fish; ATP; ADP; AChE.	
Resumo: 	The effects of various levels of oxygen saturation and ammonia concentration on NTPDase (ecto-nucleoside triphosphate diphosphohydrolase, E.C. 3.6.1.5) and acetylcholinesterase (AChE, E.C. 3.1.1.7) activities in whole brain of teleost fish (Rhamdia quelen) were investigated. The fish were exposed to one of two different dissolved oxygen levels, including high oxygen (6.5 mg.L-1) or low oxygen (3.5 mg.L-1), and one of two different ammonia levels, including high ammonia (0.1 mg.L-1) or low ammonia (0.03 mg.L-1) levels. The four experimental groups included the following (A) control, or high dissolved oxygen plus low NH3; (B) low dissolved oxygen plus low NH3; (C) high dissolved oxygen plus high NH3; (D) low dissolved oxygen plus high NH3. We found that enzyme activities were altered after 24 h exposure in groups C and D. ATP and ADP hydrolysis in whole brain of fish was enhanced in group D after 24 h exposure by 100% and 119%, respectively, compared to the control group. After 24 h exposure, AChE activity presented an increase of 34% and 39% in groups C and D, respectively, when compared to the control group. These results are consistent with the hypothesis that low oxygen levels increase ammonia toxicity. Moreover, the hypoxic events may increase blood flow by hypoxia increasing NTPDase activity, thus producing adenosine, a potent vasodilator.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000400012	
Editor: 	Sociedade Brasileira de Ictiologia	
Relação: 	10.1590/S1679-62252009000400012	
Formato: 	text/html	
Fonte: 	Neotropical Ichthyology  v.7 n.4 2009	
Fonte: 	info:eu-repo/semantics/openAccess