Peripheral benzodiazepine receptor mapping in rat kidney. Effects of angiotensin II-induced hypertension.
Intrarenal distribution and function(s) of the peripheral benzodiazepine receptor (PBR) remain uncertain. The goals of this study were to (1) develop a specific anti-rat PBR antibody and (2) map intrarenal immunoreactive PBR (irPBR) in untreated rats and in rats that received chronic angiotensin II infusion (200 ng/kg per min, subcutaneously, 17 d). A polyclonal rabbit antibody was raised against the C-terminal end of rat PBR (aa 159 to 169). The antibody specifically recognized a single 18-kD protein in whole kidney extracts, and confocal microscopy showed exclusive mitochondrial localization of irPBR in cultured rat glial C6 cells. In control rats, irPBR was found along thick ascending limbs of Henle's loops, including the macula densa area, along distal tubules, and along collecting ducts. Vascular smooth-muscle cells were PBR-positive. General irPBR distribution was unaffected by angiotensin II treatment (systolic BP, 205 +/- 9 mmHg). However, irPBR appeared in parietal glomerular epithelial cells, atrophic proximal tubules, and infiltrating mononuclear cells. In conclusion, the results suggest previously unsuspected roles of PBR in the control of glomerular dynamics and in proximal tubular injury/repair processes.
Bribes
Estelle
E
*Department of Immunology and Oncology, Sanofi Synthélabo Montpellier, France; and Groupe Rein et Hypertension, IURC, Montpellier, France.
Casellas
Pierre
P
*Department of Immunology and Oncology, Sanofi Synthélabo Montpellier, France; and Groupe Rein et Hypertension, IURC, Montpellier, France.
Vidal
Hubert
H
*Department of Immunology and Oncology, Sanofi Synthélabo Montpellier, France; and Groupe Rein et Hypertension, IURC, Montpellier, France.
Dussossoy
Danielle
D
*Department of Immunology and Oncology, Sanofi Synthélabo Montpellier, France; and Groupe Rein et Hypertension, IURC, Montpellier, France.
Casellas
Daniel
D
*Department of Immunology and Oncology, Sanofi Synthélabo Montpellier, France; and Groupe Rein et Hypertension, IURC, Montpellier, France.
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D006973:Hypertension / Q000139:chemically induced* / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000378:metabolism*; D012016:Reference Values; D012709:Serum Albumin / Q000032:analysis; D014018:Tissue Distribution
D011963:Receptors, GABA-A; D012709:Serum Albumin; D000804:Angiotensin II