[Analysis of the relationship between temperatures and the process of diaphragmatic cell membrane repolarization in...

The temperature dependence (TD) of the membrane repolarization process (RP) in muscle cells within the range of 10--20 degrees C following preliminary cooling of muscles, the effect of treatment of diaphragmatic muscles (DM) with ouabain (Ou) (10(-4) M) and administration of 2,4-dinitrophenol (2,4-DNP) (1.5 mg/100g) on RP were studied in experiments on isolated DM of adult (7--8-month-old) and old (28--32-month-old) male white rats. Ou and 2,4-DNP decrease the temperature coefficient Q10 of cell membrane RP of DM in the adult animals to the magnitudes approximating one, while in the old animals, 2,4-DNP does not change TD of RP and Ou reduces it from 3.824 +/- 0.440 but to 2.725 +/- 0.245. A possible age-associated reconstitution of the mechanisms of active transmembrane ion transport is suggested.