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Blood lactate accumulation in forced submerged turtles that can and cannot shunt (879.11)
Author(s) -
Rana Rahul,
Williams Cassondra,
Hicks James
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.879.11
Subject(s) - shunt (medical) , shunting , anaerobic exercise , biology , blood lactate , acclimatization , hypoxia (environmental) , metabolism , medicine , cardiology , physiology , anesthesia , anatomy , endocrinology , chemistry , heart rate , ecology , oxygen , blood pressure , organic chemistry
Freshwater turtles are capable of remaining underwater for over four months. This is in part due to their ability to reduce their metabolism in order to survive long periods of anoxia. Another unique ability freshwater turtles possess is the ability to shunt blood, or cause blood to deviate from the normal cardiovascular circuit due to pulmonary and vascular resistance changes. Although the functional significance of cardiac shunting is not well understood, one hypothesis for its function is that hypoxemia, induced by cardiac shunting, causes a reduction in metabolism. To test this hypothesis, levels of blood lactate, a product of anaerobic metabolism, were measured in animals that could and could not shunt. Atropine was given to the turtles to eliminate the ability to shunt. Higher blood lactate levels in turtles that cannot shunt would support the relationship between cardiac shunting and reduced metabolism. Red‐eared sliders were anesthetized and surgically fitted with catheters inserted into a blood vessel in the neck. The turtles were forcibly submerged for one hour. Blood samples were taken through the catheter. Alternatively, blood samples were collected from the tail vein before and after the submersion. Preliminary data showed no difference in lactate levels between turtles that can shunt and those that cannot. Lactate data were also analyzed to determine the aerobic dive limit (ADL) during forced submersions. The ADL is the duration of a submergence at which a significant increase in blood lactate concentration is observed. Results suggest turtles that were capable of shunting had an ADL falling between 20‐30 minutes. Grant Funding Source : Supported by NSF (1121324‐IOS)