STENOSIS OF THE TUBULAR NECK - A POSSIBLE MECHANISM FOR PROGRESSIVE RENAL-FAILURE

Fibrosis in chronic renal failure is closely associated with declining function, Its role in affecting function is less well defined, The ra diation model of chronic renal failure was used to examine the tissue distribution of fibrosis and scarring and its role in influencing the loss of function in chronic renal disease, A striking and progressive pattern of fibrosis and narrowing of the glomerulotubular neck was fou nd in irradiated pig kidneys, These narrowed necks increased in preval ence with time after irradiation, At 20 weeks after irradiation, the a verage neck diameter reduction was 60%, as compared with nonirradiated controls, a percentage that is consistent with a reduction in flow an d pressure at this critical point of the nephron, Glomerulotubular nec k narrowing may thus directly reduce the glomerular filtration rate of an individual nephron. Fibrotic neck stenoses may be a factor in prog ressive chronic renal failure.