Insulin regulates ionic metabolism in a fresh water teleost, anabas testudineus (bloch).
Indian J Exp Biol
;
2005 Aug; 43(8): 702-9
Artigo
em Inglês
| IMSEAR
| ID: sea-57084
ABSTRACT
Short term effects of insulin on total brain and branchial Na+K+ ATPase, Ca2+ ATPase and Na+, K+ and Ca2+ ions were investigated in A. testudineus. The increase in brain Ca2+ ATPase after alloxan treatment may account for an increased amount of intracellular calcium required for biochemical events taking place inside the cells. Branchial Na+K+ATPase was significantly stimulated while Ca2+ ATPase significantly inhibited after alloxan treatment. This suggests that alloxan exerts its inhibitory effect on the ATP-driven Ca2+ transport via; its action on the Ca2+ pump protein rather than the membrane permeability to Ca2+. The increased activity of brain Na+K+ ATPase at 3 and 24 hr by insulin to alloxan pretreated fish may account for the stimulated co-transport of glucose and its utilization for energy requirements and the excitatory action on neurons in the brain. The elevated brain Ca2+ ATPase may be due to the role of calcium as a second messenger in hormone action. At 24 hr, the activity of branchial Na+K+ ATPase and Ca2+ ATPase in alloxan pretreated specimens was significantly stimulated by insulin. This may be due to increased synthesis of these enzyme units. Administration of insulin (lU/fish) in normal fish significantly inhibited the activity of brain and branchial Na+K+ ATPase while brain Ca2+ ATPase showed a stimulatory effect at 3 and 24 hr compared to control. Inhibition of total branchial Ca2+ ATPase activity by insulin may be due to increased Ca2+ concentration. Higher plasma glucose level in alloxan treated groups confirms the diabetic effect of alloxan. Insulin reverses this effect. The possible mechanism by which insulin controls Na+K+ ATPase activity appears to be tissue specific. The results seem to be the first report on the effect of insulin on ATPase activity in a teleost. These data are consistent with the hypothesis that insulin performs a role in hydro mineral regulation in freshwater teleosts.
Texto completo:
DisponíveL
Índice:
IMSEAR (Sudeste Asiático)
Assunto principal:
Potássio
/
Sódio
/
Glicemia
/
Perciformes
/
Encéfalo
/
Cálcio
/
ATPases Transportadoras de Cálcio
/
ATPase Trocadora de Sódio-Potássio
/
Proteínas de Peixes
/
Aloxano
Idioma:
Inglês
Revista:
Indian J Exp Biol
Ano de publicação:
2005
Tipo de documento:
Artigo
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