Long-term studies of the juxtaglomerular apparatus in young microalbuminuric type 1 diabetic patients.
OBJECTIVE
To determine the long-term changes of the juxtaglomerular apparatus in incipient diabetic nephropathy.


METHODS
Three renal needle biopsies were performed on 15 young type I diabetic patients with microalbuminuria; at baseline and after an average of 2.4 and 8.2 years. Using light microscopy, 1 microm serial sections of the plastic-embedded biopsies were investigated and volumes of the juxtaglomerular apparatus and glomerulus and areas of the macula densa and lumina of the afferent and efferent arterioles were measured.


RESULTS
From baseline to second follow-up there was a significant decrease in JGA relative to glomerular volume. There was an increase in luminal area of the efferent arteriole which was paralleled by (non-significant) changes in the afferent arteriole.


CONCLUSIONS
Over a period of 8.2 years JGA size remained stable, but decreased relative to glomerular size. Also, an increase in luminal area was noted in efferent arterioles. This may be due to increased single nephron blood flow secondary to nephron loss.
Gulmann
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C
Electron Microscopy Laboratory, Institute of Experimental Clinical Research and Institute of Pathology, Aarhus Kommunehospital, Denmark.
Osterby
R
R
Bangstad
H J
HJ
D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000473:pathology*; D001160:Arterioles / Q000473:pathology; D001707:Biopsy, Needle; D003922:Diabetes Mellitus, Type 1 / Q000473:pathology*; D003928:Diabetic Nephropathies / Q000473:pathology*; D005260:Female; D006801:Humans; D007606:Juxtaglomerular Apparatus / Q000473:pathology*; D007678:Kidney Glomerulus / Q000098:blood supply / Q000473:pathology; D008297:Male; D013997:Time Factors