[Chronic sodium chloride load--a possibility for the increase of tolerance for ischemia in the kidney]

After an ischaemia lasting 1 hour as well as after an extreme hypertension lasting 210 minutes in the kidney of a rat a significant increase of the renin activity in the juxtaglomerular apparatus was found. By chronic load with sodium chloride was tried to produce a decrease of renin. In contrast to an ischaemic lesion the kidneys of the animals loaded with salt revealed a better ischaemia tolerance than those of the unloaded animals. This is expressed by a significantly increased total blood supply and cortical blood supply. On the two experimental conditions a change of the distribution of the blood supply in favour of the inner compartments of the kidneys may be observed. In the oxygen histogram of the surface of the kidney the salt-loaded kidneys reveal a better oxygenation before and after the ischaemic lesion. The kidneys loaded before show an essentially more insignificant decrease of the urine excretion than the unloaded ones.