Response of the medullary thick ascending limb to @entity1375 in the XXXX .

@entity1375 @entity10664 @entity3584 @entity56072 @entity1955 @entity7083 @entity35
@entity1375 in the @entity35 is associated with a decrease in kidney size and weight. We have shown previously that this decrease involves all nephron segments in the cortex and outer medulla and is especially pronounced in the medullary thick ascending limb ( @entity56072 ). Therefore, the present study was undertaken for examination of the effect of @entity1375 on the ultrastructure of the @entity35 @entity56072 . @entity1375 was induced by feeding @entity7083 ( @entity10664 ), 0.5 g/kg of food, for 4 weeks. A second group of animals received @entity10664 plus a daily injection of @entity1955 (T4). A third group was fed a normal diet only and served as control animals. The kidneys were preserved by in vivo perfusion with 3% @entity3584 , and tissue from the inner and outer stripe of the outer medulla was processed for electron microscopy. Morphometric analysis revealed a significant decrease in the cross-sectional area of the @entity56072 in both the inner and outer stripe of the outer medulla in @entity1375 animals. No changes were observed in the surface density of either the apical or basolateral plasma membranes following @entity10664 treatment. However, when calculated per millimeter tubule, there was a significant decrease in the surface area (SL) of both the apical and basolateral plasma membranes of the @entity56072 of @entity1375 animals in comparison with control animals. Simultaneous treatment with T4 prevented the @entity10664 -induced reduction in both tubule cross-sectional area and in the SL of the plasma membrane. These findings suggest that the observed changes in SL of the plasma membrane of the @entity56072 are due to a regulatory role of thyroid hormone in membrane proliferation as well as in cell growth in general.
