ATTENUATION OF RENOMEDULLARY PHOSPHOLIPASE-C ISOZYME, PLC-DELTA-1, INSPONTANEOUSLY HYPERTENSIVE RATS

The distributional patterns of PLC isozymes within the kidney were inv estigated using spontaneously hypertensive rats (SHRs) and normotensiv e Wistar-Kyoto (WKY) rats at 4 and 12 weeks of age. PLC-beta 1, PLC-be ta 3 and PLC-delta 1 quantified by Western blot analysis, were present in the highest concentrations in the inner medulla of fats at both 4 and 12 weeks of age. On the other hand, PLC-beta 4, PLC-gamma 1 and PL C-gamma 2 were distributed almost equally among the regions for the ra ts of both ages. When compared with WKY rats at 12 weeks of age, the a mounts of PLC-beta 1, PLC-beta 3, PLC-gamma 1, PLC-gamma 2, and PLC-de lta 1 in the inner medulla of SHRs were significantly lower, and the a mount of PLC-delta 1 in the inner stripe of the outer medulla was also significantly lower. Even at the prehypertensive stage at 4 weeks of age, the inner medullary concentration of PLC-delta 1 was significantl y lower in SHRs than WKY rats. These results suggest that PLC-delta 1 would play an important role in the development of hypertension.