In Korea, hypertension is the most common cause of death, however, it´s pathogenesis is still unknown. There´s a well-known hypothesis that essential hypertension is a disorder of accluturated peoples and is caused specifically by the acquired habit of eating salt.
The study is made to know the ultrastructural change of rat kidney by salt only. Three different concentrations of salt(0.4％, 4.0％ and 8.0％ of diet) were fed for 20 weeks.
The results were as follows：
1. There was no specific change in control and low salt(0.4％) diet group.
2. In middle range salt(4.0％) diet group, widening of the glomerular capillary endothelial junction, focal adhesion of foot processes of podocytes, a few myeline formation, and focal irregularity of the capillary basement membrane were observed from 6th week, and the changes were more severe in long-feeding groups. The small arteries were showing marked hypertrophy of the smooth muscle cells with degeneration of the internal elastic lamina. However, the changes were somewhat different between animals.
3. In high salt(8.0％) diet group, the similar change with the middle range salt diet group was noted, but it was more early developed and more severe for time.
There was striking myelin formation of the capillary endothlial cells, degeneration of the proximal convoluted tubular cells, widening of the intercellular space of small arterial smooth media, and proliferation of the mesangial cells. These degrees of change were also variable among animals.
In summary, the results obtained by present study indicate that high salt intake alone alsobrings about hyperplastic and degenerative change that is similar to changes of hypertension in rats kidney.
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