The mechanism of proteinuria in three different models of renovascular hypertension in the rat.

The proteinuria was measured in two-kidney hypertensive rats, in rats made hypertensive by aortic stenosis, in one-kidney hypertensive rats and in a group of control sham-operated animals. It was significantly increased in those of the first and second groups in direct correlation with the PRA which was elevated, while it was only slightly raised in those of the third group with a normal PRA. Following removal of the clip the proteinuria decreased in the two-kidney hypertensive rats, whilst it increased in the other two groups. It is suggested that in the latter cases the increase in protein excretion after removal of the clip could be due to an increase in the blood flow and filtration rate of the revascularized kidneys, whilst in the former this effect could be masked by the constant decreases in proteinuria from the intact kidney due to the fall in the PRA.