First published online October 7, 2004
Journal of Experimental Biology 207, 3855-3864 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01180
No hemoglobin but NO: the icefish (Chionodraco hamatus) heart as a paradigm
D. Pellegrino1,2,
C. A. Palmerini3 and
B. Tota2,4,*
1 Department of Pharmaco-Biology, University of Calabria, 87030, Arcavacata
di Rende, CS, Italy
2 Department of Cellular Biology, University of Calabria, 87030, Arcavacata
di Rende, CS, Italy
3 Department of Cellular and Molecular Biology, University of Perugia,
06126, Perugia, Italy
4 Zoological Station `A. Dohrn', Villa Comunale, 80121, Napoli,
Italy
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Fig. 1. (A) Scheme of the perfusion apparatus (left) connected with the
amperometric gas sensor (right) used for nitrite detection in the cardiac
effluent. (B,C) The myoarchitecture of the icefish heart showing the extensive
and fully trabeculate ventricular wall. (B) Histological longitudinal section
(Sirius Red staining) (bar, 0.25 cm); (C) scanning electron micrograph with
details of the myocardial trabeculae and the intertrabecular spaces (lacunae)
(bar, 100 µm). (D) Transmission electron micrograph showing mitocondria and
myofibrils in ventricular myocytes. (J. M. Icardo and B. Tota, unpublished
material). P, perfusate; PT, pressure transducer.
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Fig. 2. Cumulative concentration-response curve showing the effect of
L-arginine (L-Arg; from 10–7 to
10–5 mol l–1) on stroke volume
(VS) and stroke work (WS) in isolated
and perfused icefish hearts. Percentage changes were evaluated as means
± S.E.M. of five experiments. Asterisks indicate values
significantly different from the control value:
*P<0.05, **P<0.025.
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Fig. 4. Effects of
L-N5-N-iminoethyl-L-ornithine
(L-NIO; 10–5 mol l–1),
1H-[1,2,4]oxadiazole-[4,3-a]quinoxalin-1-one (ODQ; 10–5 mol
l–1) and 8-bromo-guanosine 3'5'-cyclic
monophosphate (8Br-cGMP; 10–5 mol l–1) on
stroke volume (VS) and stroke work
(WS) in isolated and perfused icefish hearts. Percentage
changes were evaluated as means ± S.E.M. of four experiments
for each group. Asterisks indicate values significantly different from the
control value: *P<0.05;
**P<0.025).
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Fig. 3. (A) Cumulative concentration–response curve showing the effect of
3-morpholinosydnonimine (SIN-1; from 10–7 to
10–5 mol l–1) on stroke volume
(VS) and stroke work (WS) in isolated
and perfused icefish hearts. (B) Effects of 3-morpholinosydnonimine (SIN-1;
10–5 mol l–1) before and after treatment
with superoxide dismutase (SOD; 10 i.u. ml–1) on stroke
volume (VS) and stroke work (WS) in
isolated and perfused icefish hearts. Percentage changes were evaluated as
means ± S.E.M. of five (A) and four (B) experiments.
Asterisks indicate values significantly different from the control value:
*P<0.05; **P<0.025.
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Fig. 5. (A) NADPH-diaphorase in the icefish ventricle. (Bottom) Representative
image showing the localization of NOS in paraformaldehyde-fixed transverse
ventricular sections (5 µm) processed as described in Materials and
methods. Note the dark blue reaction product detecting NOS activity in
endocardial endothelial (EE) cells (arrowhead) and cardiomyocytes (arrow)
(100x). (Top) Control image obtained by incubating transverse
ventricular sections in absence of NADPH (100x). (B) iNOS
immunofluorescence. Frozen transverse ventricular sections (7 µm) were
incubated with 1:100 anti-iNOS antibody as described in Materials and methods.
Fluorescent immunolabeling of iNOS in the icefish ventricle is densely
localized in the cytoplasm of the myocardiocytes (white arrowhead). Note the
absence of iNOS in the subepicardial layer (white arrow) and in the EE cells
(yellow arrow). Bar, 40 µm.
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© The Company of Biologists Ltd 2004
