| Cod (Gadus morhua) Cardiorespiratory Physiology and Hypoxia Tolerance following Acclimation to Low-Oxygen Conditions. | |
| | |
MedLine Citation:
|
PMID: 21050128 Owner: NLM Status: In-Data-Review |
Abstract/OtherAbstract:
|
Abstract Previous research has shown that hypoxia-acclimated Atlantic cod (Gadus morhua) have significantly reduced cardiac function but can consume more oxygen for a given cardiac output (Q). However, it is not known (1) which physiological changes permit a greater "oxygen pulse" (oxygen consumed per mL of blood pumped) in hypoxia-acclimated individuals or (2) whether chronic exposure to low-oxygen conditions improves the hypoxia tolerance of cod. Thus, we exposed normoxia- and hypoxia-acclimated (>6 wk at a water oxygen partial pressure [P(w)o(2)] of ∼8-9 kPa) cod to a graded normoxia challenge until loss of equilibrium occurred while recording the following cardiorespiratory variables: oxygen consumption (Mo(2)), ventilatory rate, cardiac function (Q, heart rate f(H), and stroke volume S(V)), ventral aortic blood pressure (P(VA)), venous oxygen partial pressure (P(v)o(2)) and oxygen content (C(v)o(2)), plasma catecholamines, and blood hemoglobin ([Hb]) and hematocrit (Hct). In addition, we performed in vitro hemoglobin oxygen binding curves to examine whether hypoxia acclimation influences hemoglobin functional properties. Numerous physiological adjustments occurred in vivo during the >6 wk of hypoxia acclimation: that is, increased f(H), decreased S(V) and Q, elevated [Hb], enhanced tissue oxygen extraction (by 10% at a P(w)o(2) of 20 kPa), and a more robust stress response as evidenced by circulating catecholamine levels that were two to eight times higher when fish were acutely exposed to severe hypoxia. In contrast, chronic hypoxia had no significant effect on the affinity of hemoglobin for oxygen, on in vitro hemoglobin oxygen carrying capacity, or on the cod's hypoxia tolerance (H(crit); the P(w)o(2) at which the fish lost equilibrium, which was 4.3 ± 0.2 and 4.8 ± 0.3 kPa in normoxia- and hypoxia-acclimated fish, respectively). These data suggest that while chronic hypoxia results in numerous physiological adjustments, these changes do not improve the cod's capacity to tolerate low-oxygen conditions. |
| | |
Authors:
|
L H Petersen; A Kurt Gamperl |
Related Documents
:
|
5965898 - The effects of hypoxia in the new-born lamb before and after denervation of the carotid... 18206428 - Intermittent hypoxia reduces cerebrovascular sensitivity to isocapnic hypoxia in humans. 2594738 - Pulmonary vasodilator action of ligustrazine, active principle of a traditional chinese... 3356658 - Role of barometric pressure in pulmonary fluid balance and oxygen transport. 5770898 - The kidneys and arterial pressure in immature and adult rabbits. 18463668 - Endothelium-dependent vasodilation in conduit and resistance vessels in relation to the... |
Publication Detail:
|
Type: Journal Article |
Journal Detail:
|
Title: Physiological and biochemical zoology : PBZ Volume: 84 ISSN: 1537-5293 ISO Abbreviation: Physiol. Biochem. Zool. Publication Date: 2011 Jan-Feb |
Date Detail:
|
Created Date: 2011-04-04 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 100883369 Medline TA: Physiol Biochem Zool Country: United States |
Other Details:
|
Languages: eng Pagination: 18-31 Citation Subset: IM |
Affiliation:
|
Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, A1C 5S7 Newfoundland, Canada. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Type 2 vaccine-derived poliovirus from patients with acute flaccid paralysis in china: current immun...
Next Document: The evolution of cold tolerance in Drosophila larvae.