In the present study we investigated the in vivo (acute and chronic) and in vitro effects of
proline on NTPDase and
5'-nucleotidase activities in synaptosomes obtained from cerebral cortex of rats. For acute administration, 29-day-old rats received one
subcutaneous injection of
proline (18.2 micromol/g
body weight) or an equivalent volume of
0.9% saline solution (control) and were killed 1 h later. For chronic treatment, buffered
proline was injected subcutaneously into rats twice a day
at 10 h intervals from the 6th to the 28th day of age. Rats were killed 12 h after the last injection. Results showed that acute and chronic
proline administration provoked a reduction (25%) of
ATP hydrolysis, but did not alter
ADP and
AMP hydrolysis. We also verified the in vitro effect of
proline (3.0 microM-1.0 mM) on
nucleotide hydrolysis in synaptosomes from cerebral cortex of rats. In contrast to the in vivo studies, it was not observed any statistically significant alteration on
ATP,
ADP and
AMP hydrolysis. In conclusion, according to our results, it seems reasonable to postulate that
proline administration alters the hydrolysis of
ATP and probably affects the responses mediated by
adenine nucleotides in the central nervous system of
proline treated rats.