Branchial O-2 chemoreceptors in Nile tilapia Oreochromis niloticus: Control of cardiorespiratory function in response to hypoxia

Autor(es)

Zeraik, Vivian M. ^[1] ; Belao, Thiago C. ^[1] ; Florindo, Luiz Henrique ^[2] ; Kalinin, Ana L. ^[1] ; Tadeu Rantin, F. ^[1]

Afiliação do(s) autor(es)

^[1] Fed Univ Sao Carlos UFSCar, Dept Physiol Sci, Lab Zoophysiol & Comparat Biochem, BR-13565905 Sao Carlos, SP - Brazil

^[2] Sao Paulo State Univ UNESP IBILCE, Dept Bot & Zool, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY; v. 166, n. 1, p. 17-25, SEP 2013.
• Citações Web of Science: 5

Resumo

This study examined the distribution and orientation of gill O-2 chemoreceptors in Oreochromis niloticus and their role in cardiorespiratory responses to graded hypoxia. Intact fish, and a group with the first gill arch excised (operated), were submitted to graded hypoxia and their cardiorespiratory responses (oxygen uptake - (V) over dotO(2), breathing frequency - f(R), ventilatory stroke volume - V-T, gill ventilation - (V) over dot(G), O-2 extraction from the ventilatory current - EO2, and heart rate - f(H)) were compared. Their responses to bolus injections of NaCN into the bloodstream (internal) or ventilatory water stream (external) were also determined. The (V) over dotO(2) of operated fish was significantly lower at the deepest levels of hypoxia. Neither reflex bradycardia nor ventilatory responses were completely abolished by bilateral excision of the first gill arch. EO2 of the operated group was consistently lower than the intact group. The responses to internal and external NaCN included transient decreases in f(H) and increases in f(R) and V-amp (ventilation amplitude). These cardiorespiratory responses were attenuated but not abolished in the operated group, indicating that chemoreceptors are not restricted to the first gill arch, and are sensitive to oxygen levels in both blood and water. (c) 2013 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 10/03599-2 - Localização, distribuição e orientação dos quimiorreceptores de O2 branquiais em tilápia-do-Nilo (Oreochromis niloticus): Controle das respostas cardio-respiratórias à hipóxia
• Beneficiário: Vivian Maria Zeraik
• Modalidade de apoio: Bolsas no Brasil - Mestrado