Alpha-2b adrenergic receptors: immunolocalization and regulation by
potassium depletion in rat kidney.
Huang, Liping, Yuan Yuan Wei, Akemi Hotokezaka, Jennifer Dickey, and
Mark D. Okusa.
Department of Medicine, University of Virginia Health Sciences
Center, Charlottesville, VA 22908
APStracts 3:0012F, 1996.
Regulation of transport processes in renal epithelial cells in
response to alpha-2 adrenergic receptors ([alpha]2-ARs) stimulation
is likely due to specific effects of the A, B or the 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-adrenergic receptor 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. Lastly, 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.
Received 25 September 1995; accepted in final form 26 December
1995.
APS Manuscript Number F323-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 22 January 96