|
|
| [PMID]: | 25244375 |
| [Au] Autor: | Zimmer AM; Wood CM |
| [Ad] Endereço: | Department of Biology, McMaster University, Hamilton, Ontario L8S 4K1, Canada; 2Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada; 3Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada, and Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, Florida 33149. |
| [Ti] Título: | Exposure to acute severe hypoxia leads to increased urea loss and disruptions in acid-base and ionoregulatory balance in dogfish sharks (Squalus acanthias). |
| [So] Source: | Physiol Biochem Zool;87(5):623-39, 2014 Sep-Oct. | | [Is] ISSN: | 1537-5293 |
| [Cp] País de publicação: | United States |
| [La] Idioma: | eng |
| [Ab] Resumo: | The effects of acute moderate (20% air O2 saturation; 6-h exposure) and severe (5% air O2 saturation; 4-h exposure) hypoxia on N-waste, acid-base, and ion balance in dogfish sharks (Squalus acanthias suckleyi) were evaluated. We predicted that the synthesis and/or retention of urea, which are active processes, would be inhibited by hypoxia. Exposure to moderate hypoxia had negligible effects on N-waste fluxes or systemic physiology, except for a modest rise in plasma lactate. Exposure to severe hypoxia led to a significant increase in urea excretion (Jurea), while plasma, liver, and muscle urea concentrations were unchanged, suggesting a loss of urea retention. Ammonia excretion (Jamm) was elevated during normoxic recovery. Moreover, severe hypoxia led to disruptions in acid-base balance, indicated by a large increase in plasma [lactate] and substantial decreases in arterial pHa and plasma [Formula: see text], as well as loss of ionic homeostasis, indicated by increases in plasma [Mg(2+)], [Ca(2+)], and [Na(+)]. We suggest that severe hypoxia in dogfish sharks leads to a reduction in active gill homeostatic processes, such as urea retention, acid-base regulation and ionoregulation, and/or an osmoregulatory compromise due to increased functional gill surface area. Overall, the results provide a comprehensive picture of the physiological responses to a severe degree of hypoxia in an ancient fish species. |
| [Mh] Termos MeSH primário: |
Oxigênio/metabolismo
Squalus acanthias/fisiologia
Ureia/metabolismo
Equilíbrio Hidroeletrolítico
|
| [Mh] Termos MeSH secundário: |
Anaerobiose
Animais
Concentração de Íons de Hidrogênio
Masculino
Squalus
|
| [Pt] Tipo de publicação: | JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T |
[Nm] Nome de substância:
| 8W8T17847W (Urea); S88TT14065 (Oxygen) |
| [Em] Mês de entrada: | 1507 |
| [Cu] Atualização por classe: | 140923 |
[Lr] Data última revisão:
| 140923 |
| [Sb] Subgrupo de revista: | IM |
| [Da] Data de entrada para processamento: | 140923 |
| [St] Status: | MEDLINE |
| [do] DOI: | 10.1086/677884 |
| |
|
|
