Differential expression of pkc isoforms in fresh and cultured rabbit ccd. Wilborn, Teresa W., and James A. Schafer. Departments of Physiology and Biophysics, Nephrology Training and Research Center, University of Alabama at Birmingham, Birmingham, AL 35294
APStracts 2:0201F, 1995.
Growth of rabbit cortical collecting duct (CCD) cells in primary culture results in a phenotype in which there is a stable stimulation of Na+ transport by AVP. Our objective was to determine if this altered phenotype was associated with altered expression of protein kinase C (PKC) isoforms. Western blot analysis of extracted proteins and RT/PCR analysis of extracted RNA both showed expression of PKC-a, e and z in microdissected CCD segments, and in both fresh and cultured immunodissected CCD cells. These techniques also suggested that the rabbit CCD expresses PKC-h and q-like isoforms, which have not as yet been identified in this species. Growth of CCD cells in primary culture produced no apparent change in the level of expression of PKC-a, e or z; however, the q-like isoform was strongly expressed in fresh but only weakly expressed in cultured CCDs. The putative h isoform was more heavily expressed in cultured than in fresh CCD cells. The consequences of altered expression of these two isoforms in fresh and cultured rabbit CCD remains unknown but the possiblility exists that they are involved in the altered AVP -response of cultured cells.

Received 12 September 1995; accepted in final form 3 November
1995.
APS Manuscript Number F310-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 November 95