Increase and regression of the protective effect of high altitude acclimatization on the isoprenaline-induced necrotic lesions in the rat myocardium
Faltová, E.; Mráz, M.; Pelouch, V.; Procházka, J.; Ostádal, B.
Physiologia Bohemoslovaca 36(1): 43-52
1987
ISSN/ISBN: 0369-9463 PMID: 2954170 Document Number: 287227
Cardiac resistance to the cardiotoxic effect of isoprenaline--ISO (single dose of 0.1 mg X kg-1) was studied in rats acclimatized to intermittent high altitude--IHA (barochamber, 8 h a day, 5 days a week, stepwise up to 7000 m). The extent of lesions was evaluated quantitatively by means of the increased accumulation of 203HgCl2. Five weeks' acclimatization was followed by a marked increase in the resistance of the myocardium to the necrogenic effect of ISO; this effect was more expressed in the left ventricle, so that the right to left difference generally observed under normoxic conditions disappeared. The increased resistance of the myocardium to ISO-induced damage persisted long after the animals had been returned to normoxic conditions; even six weeks after the last hypoxic exposure the sensitivity of the myocardium to damage had still not returned to the values of unacclimatized animals.