The maximal capacity of low affinity ouabain binding sites in kidney medulla was found to be increased by 20 ± 3.8% after 2 weeks, and by 35 ± 4.5% in 4 weeks diabetes. However, in kidney cortex no similar changes could be detected. Westen blot analysis of Na+/K+-ATPase subunits in kidney medulla indicated a significant enhancement of both the α1 and β1 subunit in two and four weeks diabetic rats (α1: 35 ± 3.1, 51 ± 5.8% and β1: 31.3 ± 5.2 and 43.2 ± 6.8%, respectively). However, kidney cortex showed no significant change in any condition tested. In diabetes we could detect a significant change only in the medulla in case of the b subunit mRNA transcript, which showed 1.69 ± 0.59 and 2.89 ± 0.81 times increased in two and four weeks diabetic state, respectively. There was no change in the α1 subunit mRNA abundance. Insulin treatment of diabetic animals did not result in a complete reversal of diabetes-induced changes in ouabain binding capacity or in the amount of Na+/K+-ATPase α1 and β1 subunit protein and mRNA levels. Our data indicate a good correlation between changes in low affinity ouabain binding capacity and the level of α1 isoform in diabetic rats, and suggest an important role of the b subunit in the regulation of enzyme quantity.
|Number of pages||10|
|Journal||Acta physiologica Hungarica|
|Publication status||Published - Dec 1 1995|
- streptozotocin-induced diabetes
- α and β subunit
ASJC Scopus subject areas
- Physiology (medical)