Use este identificador para citar ou linkar para este item: http://repositorio.inpa.gov.br/handle/123/841
Título: Why is there no carbonic anhydrase activity available to fish plasma?
Autor(es): Joanne Lessard
Adalberto Luis Val
Sumihisa Aota
Assunto: Anidrase Carbônica
Peixes
Truta
ISSN: 0022-0949
Revista: Journal of Experimental Biology
Volume: 198
Resumo: Carbonic anhydrase (CA) is absent from the plasma of vertebrates. In vitro, CA in fish plasma will short-circuit the effect of catecholamines, which is to increase red blood cell (RBC) pH and volume, both of which enhance the affinity of hemoglobin for O2. CA was infused into trout for a period of 6 h and injected after 48 h, during which the animal was submitted to deep hypoxia (PO2=30­35 mmHg; 4.0­4.7 kPa). O2 content, lactate content, catecholamine levels, hematocrit, hemoglobin concentration and pHi were similar to those in the saline-infused control group. In contrast, cell volume was significantly higher and pHe, total CO2 content and organic phosphate levels were significantly lower than in the control group. The concentration of CA was not high enough completely to short-circuit the increase in pHi and red blood cell volume caused by catecholamines. The lower pHe in the CA-infused animals could enhance the activity of the Na+/H+ pump, which would keep the nucleotide triphosphate levels low. pH is a balance between acid loading at the muscle and acid excretion at the gills or the kidneys; we cannot distinguish between which of these resulted in a decrease of plasma pH. In conclusion, CA in plasma did not cause the expected reduction in blood oxygen content but did have a marked effect on plasma total CO2 content.
URI: http://repositorio.inpa.gov.br/handle/123/841
ISSN: 0022-0949
Local de publicação: Brasil
Aparece nas coleções:Coordenação de Biodiversidade (CBIO)

Arquivos associados a este item:
Arquivo Descrição TamanhoFormato 
why is there no carbonic.pdf229,78 kBAdobe PDFVisualizar/Abrir


Este item está licenciada sob uma Licença Creative Commons Creative Commons