The effect of
adenosine (
ADO) on the recovery of cellular
adenine nucleotides (AN) was evaluated in the cultured cells deprived of
oxygen and substrates (
ischemia) and in nonischemic cells (control). The primary cultured cells were obtained from microdissected rabbit proximal straight tubules. Ten-day-old cultured cells were made ischemic for 6 hr, and allowed to recover for 24 hr. At the end of
ischemia, cells were incubated with
ADO,
theophylline (T),
dipyridamole (D),
coformycin (C) or combined agents for 3 hr. Total AN (TAN) were determined after 3 and 24 hr of recovery. The results, after 3 hr of incubation, suggest that in both control and ischemic cells,
ADO is taken up by cultured cells and is preferentially converted to
nucleotides. This effect is blocked by D, which inhibits
ADO uptake, uninfluenced by C, which inhibits
ADO deaminase and potentiated by T, which inhibits
5'-nucleotidase. After 24 hr of recovery, the beneficial effects of
ADO alone or combined D, C, or T, on TAN were not seen in control cells. In contrast, in the ischemic cells, after 24 hr of recovery,
ADO + T normalized
ATP,
ADP and TAN to the preischemic levels. T alone significantly increased
ATP after 24 hr of recovery. To demonstrate further that the beneficial effect of T is due to inhibition of
5'-nucleotidase, cells were treated with
adenosine alpha, beta-methylene diphosphate in the same manner as T. Combined
ADO +
adenosine alpha, beta-methylene diphosphate normalized
ATP,
ADP and TAN after 24 hr of recovery. This finding suggests that inhibition of
5'-nucleotidase improves postischemic AN.(ABSTRACT TRUNCATED AT 250 WORDS)