Renal prostaglandin excretion and metabolism in male and female New Zealand normotensive and genetically hypertensive rats.

Reduced renal 15-hydroxyprostaglandin dehydrogenase (PGDH) activity has been proposed as a cause, subsequent to elevation of intrarenal prostaglandin (PG) E2 levels, of the development or maintenance of high blood pressure (BP) in the New Zealand genetically hypertensive (NZGH) rat. To test this hypothesis, PGDH activity in homogenates of kidneys and lungs and in urine concentration and excretion of PGE2 were determined in male and female NZGH and normotensive control (NZNR) rats. Lung PGDH activities of the four groups were similar. Renal PGDH activity was 50% lower for the male NZGH than for the male NZNR, but for the female rats no difference in renal PGDH activity was found between NZGH and NZNR. In addition, there was a large sex-related difference in renal PGDH activities, values for the female rats being only 5% to 10% of the values for males. Urine PGE2 concentration and excretion were two to five times greater for the female rats than for the males, but did not differ between male NZGH and male NZNR. From these observations, it appears that neither renal PGDH activity nor urine PGE2 levels is associated with hypertension in the New Zealand genetically hypertensive strain of rats.