Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/43810
Title: Capillary supply and fiber morphometry in rat myocardium after intermittent exposure to hypobaric hypoxia.
Author: Panisello Tafalla, Pere
Torrella Guio, Joan Ramon
Pagés, Teresa
Viscor Carrasco, Ginés
Keywords: Miocardi
Rates (Animals de laboratori)
Respiració
Anoxèmia
Influència de l'altitud
Myocardium
Rats as laboratory animals
Respiration
Anoxemia
Influence of altitude
Issue Date: 2007
Publisher: Mary Ann Liebert, Inc.
Abstract: Panisello, Pere, Joan Ramon Torrella, Teresa Pagés, and Ginés Viscor. Capillary supply and fiber morphometry in rat myocardium after intermittent exposure to hypobaric hypoxia. High Alt. Med. Biol. 8:322-330, 2007. Three groups of male rats were submitted to an intermittent hypobaric hypoxia (IHH) program for 22 days (4 h/day, 5 days/week) in a hypobaric chamber at a simulated altitude of 5000 m. Hearts were removed at the end of the program (H group) and 20 and 40 days later (P20 and P40 groups). A control group (C) was maintained at sea-level pressure. Transverse sections from myocardium were cut and histochemically stained in order to measure fiber morphometry and capillaries. We observed a progressive increase from C to H to P20 animals in capillary (4124 to 4733 to 4816 capillaries/mm2) and fiber densities (2844 to 3125 to 3284 fibers/mm2) associated with significant reductions in fiber area (273, 235, and 227 μm2), perimeter (69, 64, and 62 μm), and diffusion distances (18.2, 16.9, and 16.6 μm). The most significant differences between C and hypoxic groups were found when morphometrical and vascular fiber parameters were combined. The myocardium of the latter had more capillaries per fiber area and per fiber perimeter. These findings indicate that the IHH program elicits an adaptive response of rat myocardium to a more efficient O2 delivery to mitochondria of cardiac muscle cells. Capillarization and fiber morphometric changes showed marked differences over time. In all cases, P20 had higher capillarization parameters and fiber morphometry reductions than H, thus indicating that a delay of about 20 days exists after the hypoxic stimulus ceases to reach complete angiogenesis and fiber morphometry changes. However, P40 animals showed a recovery to basal values of the parameters related to fiber morphometry (area, perimeter, and diffusion distances), but maintained high capillarity values (capillary density, NCF, CCA, CCP).
Note: Reproducció del document publicat a: http://dx.doi.org/10.1089/ham.2007.1030
It is part of: High Altitude Medicine & Biology, 2007, vol. 8, num. 4, p. 322-330
Related resource: http://dx.doi.org/10.1089/ham.2007.1030
URI: http://hdl.handle.net/2445/43810
ISSN: 1527-0297
Appears in Collections:Articles publicats en revistes (Biologia Cel·lular, Fisiologia i Immunologia)

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