title: Atubular glomeruli in a rat model of polycystic kidney disease.
abstract: BACKGROUND
  Autosomal-dominant polycystic kidney disease (ADPKD) is associated with a progressive decline in glomerular filtration rate (GFR) that often leads to end-stage renal disease. The basis for this decline in GFR is poorly understood.
  
  
  METHODS
  Glomeruli in heterozygous Han:SPRD rats with ADPKD and their normal litter mates were studied by light microscopy, using serial sectioning techniques. The connections of the renal corpuscles to proximal tubules were classified as normal, atrophied, or absent (atubular glomerulus). Renal corpuscles also were examined by scanning electron microscopy. Single nephron glomerular blood flows were determined using microspheres.
  
  
  RESULTS
  In the kidneys of six-month-old rats with ADPKD, 50% of the glomeruli were atubular and another 26% were associated with atrophied neck segments; these glomeruli were most often smaller in size than normal. About 16% of the glomeruli were hypertrophied and had normal connections to proximal tubules. Sclerotic changes in cystic kidney glomeruli were usually mild or moderate, and belied the failure of glomerular function. Glomerular blood flow in the cystic kidneys averaged half of normal and was markedly heterogeneous; the majority of small glomeruli displayed very low blood flows and a few showed relatively high blood flows. Fewer glomerular abnormalities were found in rats treated for five months with potassium citrate in their drinking water.
  
  
  CONCLUSIONS
  The diminished GFR in the rat with ADPKD can be accounted for largely by the formation of atubular glomeruli. Compensatory glomerular hypertrophy also is present and may contribute to the progression of the renal disease.
authors.affiliation: Department of Cellular and Integrative Physiology, Indiana UniversitySchool of Medicine, Indianapolis, Indiana, USA. gtanner@iupui.edu
authors.forename: George A
authors.initials: GA
authors.lastname: Tanner
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Tielker
authors.forename: Bret A
authors.initials: BA
authors.lastname: Connors
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Phillips
authors.forename: Judith A
authors.initials: JA
authors.lastname: Tanner
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Evan
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005919:Glomerular Filtration Rate; D007678:Kidney Glomerulus / Q000473:pathology* / Q000648:ultrastructure; D007687:Kidney Tubules, Proximal / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning; D007690:Polycystic Kidney Diseases / Q000473:pathology*; D051381:Rats; D011922:Rats, Mutant Strains; D017207:Rats, Sprague-Dawley