Biomedical subjects

A M Battastini

Publications and source records attributed to A M Battastini.

24 records · Page 2Linked to original sources

PubMed1993

Postnatal development of ATPase-ADPase activities in synaptosomal fraction from cerebral cortex of rats.

ATPase-ADPase activities in synaptosomes from cerebral cortex was measured in rats of various ages (0-, 7-, 10-, 14- and 21- and 60-90-days). The activities (nmol Pi/min/mg) increased steadily from birth, reaching maximum values at 21 days of age. The increase was primarily due to increases in Vmax; the Km values are the same from birth until adult age. The developmental profile was similar for ATPase-ADPase activities and acetylcholinesterase from the same fraction. Several specific ATPase inhibitors and Ap5A (P1P5-di(adenosine-5)-pentaphosphate) did not interfere with the hydrolysis of ATP and ADP at all ages studied, suggesting that classical ATPases and adenylate kinase were not involved in the degradation of both nucleotides by synaptosomal fraction in the assay conditions. Other phosphatases were also ruled out. It is conceivable that ATPase-ADPase activities play an important role in neurotransmitter metabolism.

Adenosine Triphosphatases↗

PubMed1991

Characterization of an ATP diphosphohydrolase (EC 3.6.1.5) in synaptosomes from cerebral cortex of adult rats.

Data from the literature have demonstrated that synaptosomal preparations from various sources can hydrolyze externally added ATP. Various authors characterized this activity as an ecto-ATPase. In the present report, we demonstrate that synaptosomal preparations obtained from the cerebral cortex of rats show ATPase activity that could not be dissociated from ADPase activity, suggesting that an ATP-diphosphohydrolase is involved in ATP and ADP hydrolysis. Furthermore, the ATP and ADP hydrolysis could not be attributed to associations of enzymes that could mimic an ATP-diphosphohydrolase because none of the following activities were detected in our assay conditions inorganic pyrophosphatase, adenylate kinase, or nonspecific phosphatases. A possible association between an ATPase and an ADPase was excluded on the basis of both the kinetics and much additional data on inhibitors, ion dependence, pH, etc. The present results demonstrate that in synaptosomal preparations from cerebral cortex an ATP-diphosphohydrolase is involved, at least in part, in ATP and ADP hydrolysis.

Adenosine Diphosphate↗

PubMed1991

Effects of undernutrition during suckling on ATP and ADP hydrolysis by synaptosomes from the cerebral cortex of adult rats.

1. Early undernutrition can cause permanent functional changes in the central nervous system. Alterations in enzymes involved in neurotransmitter metabolism have been reported to result from early undernutrition. 2. In a previous study, we demonstrated that undernutrition during suckling decreases ATP and ADP hydrolysis by synaptosomes from cerebral cortex by about 20% of the value found in 20-day-old well-nourished rats (J. B. T. Rocha, C. F. Mello, J. J. F. Sarkis and R. D. Dias, British Journal of Nutrition, 63:273-283, 1990). In the present study, we investigated whether this deficit persists in synaptosomes from cerebral cortex of nutritionally rehabilitated adult rats. 3. Rats were undernourished from birth to 25 days of life by feeding their dams a 7% casein (w/w) diet, while well-nourished offspring were fed by mothers maintained on a 28% casein diet. 4. In contrast to the results previously obtained in young rats, the synaptosomes obtained from the cerebral cortex of early undernourished adult rats hydrolyzed ATP and ADP more efficiently than did those obtained from well-nourished rats. Specific activity (nmol min-1 mg protein-1, mean +/- SD) was 114.9 +/- 9.5 for undernourished rats (N = 8) vs 94.1 +/- 9.5 for well-nourished rats (N = 8) for ATP, and 50.4 +/- 6.1 (N = 8) vs 38.8 +/- 4.5 (N = 8) for ADP. These results suggest that the deficits found in young rats disappear in rehabilitated adult rats.

Adenosine Diphosphate↗

PubMed1990

Ontogeny of ATP and ADP hydrolysis by cerebral cortex synaptosomes from rats.

In the present study, we examined the ontogeny of ATP and ADP hydrolysis by cerebral cortex synaptosomes from rats of various ages (0-, 7-, 14-, 21- and 60 to 90-day-old rats) in order to learn whether hydrolytic activity increases during the period of intense brain growth, as has been reported for other enzymes involved in neurotransmitter metabolism. The results demonstrate that ATP and ADP hydrolyzing activities increase in parallel from birth until the second postnatal week (about 4-fold), followed by a slight and statistically insignificant increase until the animal reaches adulthood. The maximum increase in nucleotide hydrolysis coincided with maximum brain growth, which may indicate a role for the enzyme in neurotransmission. Furthermore, the parallel development of both activities (ATPase and ADPase) strongly suggest that a single enzyme, an ATP diphosphohydrolase, is involved in ATP and ADP hydrolysis by the synaptosomal fraction.

Adenosine Diphosphate↗

PubMed1990

Effects of chronic treatment with high doses of chlorpromazine on ATP and ADP hydrolysis by synaptosomal fractions from the rat caudate nucleus.

Several studies have indicated that chlorpromazine and its metabolites affect ATP hydrolysis by brain and liver plasma membranes in vitro. The present report examines whether chronic treatment (12 days) with high doses of chlorpromazine (10 and 40 mg/kg) could affect ATP and ADP hydrolysis by synaptosomal fractions from the rat caudate nucleus. Both doses of chlorpromazine caused significant and parallel decreases (23 to 31%) in the ATP and ADP hydrolysis. The parallelism between the effects of chlorpromazine on ATP and ADP hydrolysis suggests the participation of a single enzyme (ATP diphosphohydrolase) in nucleotide hydrolysis.

Adenosine Diphosphate↗

PubMed1988

Effects of Piper sp extract on pregnancy in rats.

Abortive effects on cattle have been attributed to Piper sp, popularly called Pariparoba. In the present study we tested the possible toxicity of this plant by analyzing gestational outcome parameters in female rats given 300 mg/kg of an aqueous extract of Piper sp leaves and stalks per os, daily, between the 9th and the 21st day of pregnancy. The animals were killed just before delivery and the following features were observed: numbers of corpora albicantia, fetuses and reabsorptions; weights of fetuses, placentae and fetal membranes; fetal sex and the presence of overt malformations in fetuses; and implantation and reabsorption indices. No significant differences were detected between control and treated groups. The results suggest that Piper sp does not modify gestational outcome in rats.

Abortion, Spontaneous↗