Renal thromboxane synthesis in excised kidney distal to renovascular lesions

Excision of a kidney with three distinct zones of perfusion was required in a patient with renovascular hypertension. One third of the kidney was normal, one third was ischemic from a stenotic artery, and one third was severely ischemic from a completely occluded artery. This provided a unique opportunity to study renal prostaglandin production in hypoperfused and control tissue by radioimmunoassays of incubated tissue slices. The thromboxane-prostacyclin synthesis ratio for the outer cortex increased from 2.2 in control tissue to 5.8 in moderately ischemic tissue and 11.3 in severely ischemic tissue; for the inner cortex, 2.1 to 6.3 and 8.8; and for the medulla, 0.4 to 1.2 and 3.0, respectively . Similar ratios were noted for thromboxane-prostaglandin E2. This correlates, for the first time in man, absolute and relative increases in renal thromboxane synthesis with renovascular hypertension.