Kidney 15-hydroxy-prostaglandin-dehydrogenase activity during the development of experimental hypertension in the rat

15-hydroxy-prostaglandin-dehydrogenase (PGDH) activity was studied in rat kidney homogenates during the development of hypertension, within 20 days after left renal artery constriction by a solid silver clip. In the ischemic kidney PGDH activity increased at day 6, reached maximum at day 10, then progressively at day 15 and returned to normal levels at day 20. No difference was found between contralateral kidneys and kidneys of normotensive control rats. Variations of PGDH activity did not seem to be related to either renal perfusion pressure or renin production. Increased PGDH activity may be a consequence of an enzyme induction following increased PG-synthetase activity, or it could be viewed as a defence mechanism, according to the hypothesis of a prohypertensive effect of PG in the rat.