Please use this identifier to cite or link to this item: https://repositorio.inpa.gov.br/handle/1/19432
Title: Biochemical adjustments to hypoxia by Amazon cichlids.
Authors: Val, Vera Maria Fonseca Almeida e
Farias, Izeni P.
Silva, M. N.P.
Duncan, Wallice Luiz Paxiuba
Val, Adalberto Luis
Keywords: Isoenzyme
Lactate Dehydrogenase
Analysis Of Variance
Animals
Anoxia
Brain
Electrophoresis
Enzymology
Heart Muscle
Liver
Metabolism
Perch
Review
Muscle, Skeletal
Analysis Of Variance
Animal
Anoxia
Brain
Electrophoresis
Isoenzymes
L-lactate Dehydrogenase
Liver
Muscle, Skeletal
Myocardium
Perches
Issue Date: 1995
metadata.dc.publisher.journal: Brazilian journal of medical and biological research = Revista brasileira de pesquisas médicas e biológicas / Sociedade Brasileira de Biofísica ... [et al.]
metadata.dc.relation.ispartof: Volume 28, Número 11-12, Pags. 1257-1263
Abstract: The isozyme distribution of cichlid lactate dehydrogenase (LDH) is related to species environmental preferences. Cichlasoma amazonarum occurs in different environments and presents LDH tissue distribution patterns that correlate with oxygen tension at the capture location. Cichlasoma amazonarum was exposed to long-term severe hypoxia (51 days at 36.4 +/- 5.9 mmHg), tissue LDH isozyme distribution was analyzed by electrophoresis and enzyme activities were measured by monitoring the oxidation of NADH as pyruvate was reduced to lactate. The exposure of Cichlasoma amazonarum to long-term severe hypoxia resulted in changes in the tissue distribution of LDH isozymes. The major changes in response to hypoxia occurred in heart, liver and brain: isozyme A4 was activated in heart and brain, whereas isozyme B4 was activated in liver. The most significant quantitative change occurred in brain LDH of hypoxia-exposed animals which adopted muscle type kinetics, reflecting a new LDH isozyme distribution. LDH activity was significantly reduced (P < 0.05) in animals exposed to hypoxia (N = 8), suggesting an overall LDH suppression. Pyruvate inhibition decreased in all hypoxia-exposed tissues. Thus, the ability of Cichlasoma amazonarum to regulate LDH tissue expression according to oxygen availability allows the animal to survive chronic hypoxic environments. This phenotypic plasticity may occur in other hypoxia-tolerant fish species.
Appears in Collections:Artigos

Files in This Item:
There are no files associated with this item.


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.