Tissue content of adenosine, inosine and hypoxanthine in the rat kidney after ischemia and postischemic recirculation

Changes in lipid peroxidation and activities of xanthine oxidase, superoxide dismutase and catalase in kidneys of cephaloridine-administered rats.

“…As regards to this dissociation in time courses of the changes of the enzyme and the substrates, the following was speculated as its cause: not only were the cellular injuries progres sively aggravated, but simultaneously, cellular restoration was initiated and progressed during this period. Namely, repair of the in jured renal mitochondria where the level of the high-energy phosphate pool is adjusted may have been initiated similar to what was reported in the reflow of the ischemic kidney (40,41). As to the renal contents of hypoxan thine and xanthine, these levels were quan titatively sufficient enough to be oxidized by xanthine oxidase.…”

“…It is generally known that the adenine nucleotides are me tabolized into hypoxanthine, and the hy poxanthine is furthermore oxidized, in turn, to xanthine and to uric acid by xanthine oxidase (39). In addition, renal ischemia has been reported to inhibit mitochondrial respiration, to decrease the adenosine triphosphate level, and to increase the hypoxanthine and xan thine levels in the kidney (40,41). Also CER administration has been known to inhibit mitochondrial respiration in the renal cortex (7).…”

RELEASE OF 3H‐PURINES FROM [3H]‐ADENINE LABELLED RABBIT KIDNEY FOLLOWING SYMPATHETIC NERVE STIMULATION, AND ITS INHIBITION BY α‐ADRENOCEPTOR BLOCKADE

“…Thus, Haddy & Scott (1971) showed that a vasoactive substance with properties similar to adenosine was released into the venous effluent following 1 min occlusion of the renal artery. Osswald, Schmitz & Kemper (1977) recently reported significant elevation of renal adenosine content following ischaemia in the rat kidney. The tissue content of inosine and hypoxanthine was also increased.…”

Theophylline Inhibition of Renal and Cerebral Nucleoside Formation

“…Furthermore, theophylline reduces the cerebral blood flow (Gottstein & Paulson, 1972) but increases the renal blood flow (Osswald, Schmitz & Kemper, 1977). Theophylline decreases the survival of mice exposed to hypoxia and increases the cerebral concentration of adenosine 5'-monophosphate (AMP) (Thurston, Hauhart & Dirgo, 1978).…”

“…Further, theophylline per se has the opposite effect to adenosine on the release of noradrenaline from electrically stimulated adrenergic nerves (Hedquist etal., 1978). Adenosine is a potent vasodilator and increases the blood flow in the brain (Berne, Rubio & Curnish, 1974) but in the kidney adenosine is a vasoconstrictor and decreases blood flow (Osswald et al, 1977).…”