Showing papers by "Ana Maria Oliveira Battastini published in 2002"
TL;DR: It is suggested that adenosine A1 receptors in the posterior cingulate cortex inhibit memory consolidation in a way that their blockade facilitates memory for inhibitory avoidance in rats.
54 citations
TL;DR: Chronic stress reduced ADP hydrolysis and increased 5'-nucleotidase activity in the spinal cord in male rats, while no effect was observed in females with chronic stress, or after acute stress neither in males or females.
48 citations
TL;DR: The sum of ADP, GDP and UDP hydrolysis upon individual incubations with CSF was similar to the hydrolytic pattern observed when all three nucleotides were incubated together, which strongly suggests the involvement of more than one enzyme activity.
37 citations
TL;DR: The results suggest that the stimulation of the nucleotidase pathway may play an important role in attenuating seizure activity.
30 citations
TL;DR: Activation of ATPase activity by glutamate may constitute an important role in this developmental period, possibly protecting against the neurotoxicity induced by ATP, as well as producing high levels of ADP, by increasing adenosine production, a neuroprotective compound.
28 citations
TL;DR: The results suggest that the ectonucleotidase pathway responds to a mild foot-shock in AC, PC and Fr2 and may be involved in memory consolidation of step-down inhibitory avoidance in the cingulate cortex.
25 citations
TL;DR: Reduced ADP hydrolysis was observed in the blood serum of chronic stressed rats and it is possible that altered levels of ADPase activity in the serum may be a biochemical marker for chronic stress situations.
Abstract: We have previously observed that adenosine 5'-diphosphate (ADP) hydrolysis was decreased 25% in spinal cord synaptosomes of chronically stressed male rats, while no changes were observed in ATPase activity. In the present study, we investigated the effect of chronic stress on the hydrolysis of adenine nucleotides in two cerebral structures (frontal cortex and hypothalamus) and in the blood serum of male rats. Adult male Wistar rats were submitted to 1-h restraint stress/day for 45 days (chronic) and were sacrificed 24 h after the last session of stress. Adenosine 5'-triphosphate (ATP) or ADP hydrolysis was assayed in the synaptosomal fraction obtained from the frontal cortex and hypothalamus of control and chronically stressed animals. No effects on ADP or ATP hydrolysis were observed in any of the cerebral structures analyzed after chronic stress. On the other hand, reduced ADP hydrolysis was observed in the blood serum of chronic stressed rats. It is possible that the effects observed in the blood serum may represent an adaptation to chronic stress and may reflect different functions of nucleotides and/or enzymes in these tissues. It is possible that altered levels of ADPase activity in the serum may be a biochemical marker for chronic stress situations.
22 citations
TL;DR: The results suggest that thyroid hormones could be involved in the regulation of ectonucleotidase activities, such as ecto-ATP diphosphohydrolase and ecto -ATPase, possibly exerting a modulatory role in extracellular adenosine levels.
Abstract: 1. Studies have shown that adenosine transport and adenosine A1 receptors in rat brain are subjected to regulation by thyroid hormone levels. Since the ectonucleotidase pathway is an important source of adenosine extracellular, in the present study the in vitro action of T3 and T4 hormones on ectonucleotidase activities in hippocampal synaptosomes was evaluated.
13 citations