DISTRIBUTIONAL PATTERNS OF PHOSPHOLIPASE-C ISOZYMES IN RAT-KIDNEY

As the first step to investigate the physiological function of phospho lipase C (PLC), we determined the distribution patterns of PLC isozyme s in normal rat kidneys using Western blotting analysis and immunohist ochemistry. Western blotting analysis was performed in four regions (c ortex, outer stripe and inner stripe of the outer medulla, and the inn er medulla). PLC-beta 1 and beta 3 were detected in the inner stripe o f the outer medulla and the inner medulla. PLC-gamma 1 was distributed homogeneously along the corticomedullary axis. PLC-gamma 2 was observ ed in the medulla and PLC-delta 1 showed a gradual increase from the c ortex to the inner medulla, In contrast, no PLC-beta 4 was detected in all regions. On immunohistochemistry, the immunoreactivities to PLC a ntibodies were observed as follows: PLC-beta 1, from the thick ascendi ng limb (TAL) to the inner medullary collecting tubule (IMCT); PLC-bet a 3, in the glomerulus (Glm), the ascending thin limb (ATL) and the co llecting tubule; PLC-beta 4, Glm, the proximal convoluted tubule (PCT) , ATL, the distal convoluted tubule, the connecting tubule, and the co llecting tubules; PLC-gamma 1, PCT, TAL and IMCT; PLC-delta 1, homogen eously from PCT to IMCT. PLC-beta 3 immunoreactivities were detected i n the nuclei of the TAL, ATL, outer medullary collecting tubule (OMCT) and IMCT. PLC-beta 4 and gamma 2 were observed in Glm, MTAL, ATL, OMC T and IMCT. These results suggest the intrarenal site-specific existen ce of PLC isozymes that may regulate kidney functions through the PLC- mediated signal transductions.