EVIDENCE SUGGESTING A ROLE FOR PHOSPHOLIPASE-C ISOZYME, PLC-DELTA(1) IN CORTICOMEDULLARY OSMOTIC GRADIENTS IN RAT KIDNEYS

We determined the distributional patterns of phospholipase C isozymes within the rat kidneys. PLC-beta(1) was localized in the inner medulla at the highest degree followed by the inner stripe of the outer medul la, the cortex and the outer stripe of the outer medulla. PLC-gamma(1) was distributed homogeneously along the corticomedullary axis. PLC-de lta(1) showed gradual increase from the cortex to the inner medulla. T issue osmotic gradients were measured using 4 slices, resulting in gra dual increase from the cortex to the inner medulla. The pattern of PLC -delta(1) appeared very similar to the osmotic gradient in the kidney. The results suggest that the distinct patterns of the PLC isozymes ma y be associated with different signal transduction pathways along the corticomedullary axis and PLC-delta(1) may play a role in the osmoregu lation of the medullary region.