Cardiac effects of hypoxia in the neotenous tiger salamander Ambystoma tigrinum
Tom McKean*,
Guolian Li and
Kong Wei
WWAMI Medical Program and Department of Biological Sciences,
University of Idaho, Moscow, ID 83843-3051, USA

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Fig. 1. Rate of oxygen consumption of salamanders in metabolism chambers at three
levels of chamber oxygen. An asterisk denotes a significant difference
(P<0.05) between normoxia and hypoxia. Values are means + S.D.
N=3 for the high-oxygen group; N=6 for the other two
groups.
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Fig. 2. Flow and pressure traces for a buffer-perfused heart from a normoxic
salamander. Preload was set at 2 cmH2O (0.2 kPa) and afterload was
set at 16 cmH2O (1.6 kPa). 1 cmH2O=98.1 Pa.
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Fig. 3. FrankStarling relationship for buffer-perfused salamander hearts.
Values are means + S.D. 1 cmH2O=98.1 Pa.
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Fig. 4. Heart rate and cardiac output during 5 days of hypoxia in an unanesthetized
salamander. The range of oxygen levels during hypoxia was 5-8 %.
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Fig. 5. 1.8 % agarose gel showing amplicons from normoxic (E) and hypoxic (F)
salamanders. Lanes A-D show the first, second, third and fourth difference
products respectively. The scale shown on the right is in base pairs for
fragment size.
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Fig. 6. Ventricular cardiomyocytes from salamander. Two or three myocyes are
visible and are incompletely separated. Scale bar, 100 µm.
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Fig. 7. Micrographs from (A) heart, (B) gill, (C) lung and (D) ileum of
hypoxia-exposed salamanders that had been injected with colchicine. The
asterisks indicate nuclei in which chromosomal separation has been arrested by
the colchicine administration. Scale bars, 20 µm.
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© The Company of Biologists Ltd 2002