Pharmacological blockade of the cardiovascular dive response : effects on heart rate and diving behaviour in the harbour seal (Phoca vitulina) ...
While diving, harbour seals (Phoca vitulina) manage their oxygen stores through cardiovascular adjustments including bradycardia, a concurrent reduction in cardiac output, and peripheral vasoconstriction. At the surface, post-dive tachycardia facilitates rapid reloading of these oxygen stores. Altho...
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| Format: | Text |
| Language: | English |
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University of British Columbia
2009
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| Online Access: | https://dx.doi.org/10.14288/1.0090203 https://doi.library.ubc.ca/10.14288/1.0090203 |
| Summary: | While diving, harbour seals (Phoca vitulina) manage their oxygen stores through cardiovascular adjustments including bradycardia, a concurrent reduction in cardiac output, and peripheral vasoconstriction. At the surface, post-dive tachycardia facilitates rapid reloading of these oxygen stores. Although harbour seals can tolerate over 20 min of submergence, the majority of their natural dives are only 2 to 6 min and are usually followed by surface intervals that are less than 1 min, so they spend about 80 % of their time at sea submerged. Given that harbour seals meet their ecological needs through repetitive short aerobic dives, I was interested in the functional role, if any, of the cardiovascular dive response during these short dives. During voluntary diving in an 11 m deep tank, the cardiovascular responses to submergence of five captive harbour seals were manipulated using specific pharmacological antagonists, and the effects on diving behaviour were observed. Effects of pharmacological blockade on mean ... |
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