| Autor: |
Pogorelov AG; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russia., Pogorelova VN, Dubrovkin MI, Demin IP, Khrenova EV |
| Jazyk: |
ruština |
| Zdroj: |
Biofizika [Biofizika] 2002 Jul-Aug; Vol. 47 (4), pp. 744-51. |
| Abstrakt: |
Electron probe microanalysis was employed to determine the elemental concentration (K,Na,Cl) in a myocyte on cryosections of the papillary muscle of the isolated rat (Wistar) heart. Protocols of global ischemia and ischemic conditions under glucose-free anoxic perfusion were applied. It was shown that global ischemia induces potassium deficiency (94 +/- 2 mM) in the myocyte and an increase in the level of sodium (72 +/- 4 mM) and chlorine (42 +/- 1 mM) in the cytoplasm compared with intact cell (122 +/- 2; 36 +/- 1; 24 +/- 1 mM). Glucose-free anoxic perfusion leads to a smooth fall of potassium concentration in the cell up to 54 +/- 2 mM with the retention of intracellular sodium (40 +/- 1 mM) and chlorine (26 +/- 1 mM) level. The present finding suggest that, in early ischemia, specific membrane mechanisms of ion transport are activated. Among these are KNa channel, Hi(+)-Nao+ exchange, KATP channel, lactate transport from the cell, associated either with potassium efflux to the extracellular space or chlorine influx into the myocyte. It is assumed that Na/K-ATPase is also activated under ischemic conditions. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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