title: Heterogeneous downregulation of angiotensin II AT1-A and AT1-B receptors in arterioles in STZ-induced diabetic rat kidneys.
abstract: BACKGROUND
  The renin granulation of kidney arterioles is enhanced in diabetes despite the fact that the level of angiotensin II in the diabetic kidney is elevated. Therefore, the number of angiotensin II AT1-A and AT1-B receptors in afferent and efferent arteriole's renin-positive and renin-negative smooth muscle cells (SMC) was estimated.
  
  
  METHODS
  Immunohistochemistry at the electron microscopic level was combined with 3D stereological sampling techniques.
  
  
  RESULTS
  In diabetes the enhanced downregulation of AT1-B receptors in the renin-positive than in the renin-negative SMCs in both arterioles was resulted: the significant difference in the number of AT1 (AT1-A + AT1-B) receptors between the two types of SMCs in the normal rats was further increased in diabetes and in contrast with the significant difference observed between the afferent and efferent arterioles in the normal animals, there was no such difference in diabetes.
  
  
  CONCLUSIONS
  The enhanced downregulation of the AT1-B receptors in the renin-negative SMCs in the efferent arterioles demonstrates that the regulation of the glomerular filtration rate by the pre- and postglomerular arterioles is changed in diabetes. The enhanced downregulation of the AT1-B receptors in the renin-positive SMCs in the arterioles may result in an enhanced level of renin granulation in the arterioles.
authors.affiliation: Department of Pathology, University of Szeged, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Razga
authors.affiliation: Department of Pediatrics, University of Szeged, Állomás Utca 2, Szeged 6725, Hungary.
authors.forename: Gabor
authors.identifier: 0000-0002-1699-827X
authors.initials: G
authors.lastname: Kovacs
authors.affiliation: Department of Physiology, Anatomy and Neuroscience, University of Szeged, Hungary.
authors.forename: Nikolett
authors.identifier: 0000-0002-9774-1387
authors.initials: N
authors.lastname: Bódi
authors.affiliation: Department of Physiology, Anatomy and Neuroscience, University of Szeged, Hungary.
authors.forename: Petra
authors.initials: P
authors.lastname: Talapka
authors.affiliation: Electron Microscopy and Stereology Research Laboratory, University of Aarhus, Denmark.
authors.forename: Jens Randel
authors.initials: JR
authors.lastname: Nyengaard
mesh_terms: D000804:Angiotensin II / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001160:Arterioles / Q000378:metabolism; D003920:Diabetes Mellitus / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000473:pathology; D004195:Disease Models, Animal; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D051381:Rats; D044140:Receptor, Angiotensin, Type 1 / Q000096:biosynthesis* / Q000235:genetics; D044139:Receptor, Angiotensin, Type 2 / Q000096:biosynthesis* / Q000235:genetics; D012083:Renin / Q000235:genetics / Q000378:metabolism
chemical_list: D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D000804:Angiotensin II; D012083:Renin