Alpha 2B-adrenergic receptors: immunolocalization and regulation by potassium depletion in rat kidney.
Regulation of transport processes in renal epithelial cells in response to alpha 2-adrenergic receptor (alpha 2-AR) stimulation is likely due to specific effects of the A-, B-, or C-subtype alpha 2-AR. The purpose of the present study was 1) to examine the precise localization, using subtype-specific antibodies, the B-subtype alpha 2-AR protein, the most abundant alpha 2-AR in rat kidney; and 2) to determine the effect of dietary potassium restriction, a factor known to increase alpha 2B-ARs, on the distribution of receptors. We employed a method to generate a specific antibody to the third intracellular loop of the alpha 2B-AR and demonstrated the specificity of this antibody. Our results demonstrated, for the first time, evidence for the alpha 2B-receptor protein in the basolateral membrane of proximal convoluted and straight tubules. No specific immunoreactivity was detected in other nephron segments. Finally, the increase in alpha 2B-AR expression observed previously was due to the recruitment of alpha 2B-ARs to the basolateral membrane of proximal tubules.
Huang
L
L
Department of Medicine, University of Virginia Health Sciences Center, Charlottesville 22908, USA.
Wei
Y Y
YY
Momose-Hotokezaka
A
A
Dickey
J
J
Okusa
M D
MD
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D004032:Diet; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D011191:Potassium Deficiency / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011942:Receptors, Adrenergic, alpha / Q000235:genetics / Q000378:metabolism*; D014018:Tissue Distribution; D014158:Transcription, Genetic
D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D011942:Receptors, Adrenergic, alpha