Showing papers by "Maria Rosa Chitolina Schetinger published in 2004"
TL;DR: It is suggested that temperature and time of exposure influence metabolic parameters in the plasma, liver and white muscle of silver catfish.
127 citations
TL;DR: Results demonstrate that alloxan-induced diabetes interferes with ATP, ADP, and AMP hydrolysis in platelets and synaptosomes and speculate that platelets could be used as a potential peripheral marker of central alterations in NTPDase and 5'-nucleotidase activities in diabetes.
92 citations
TL;DR: The results indicate that HS and HF diets produced mainly inhibition in acetylcholine degradation, which probably indicates a chronic alteration induced by these diets on the cholinergic system.
Abstract: In the present study we investigated a potential mechanism by which high sugar (HS) and high fat (HF) diets could affect acetylcholinesterase (AChE) activity The treatment with HS and HF diet was done for six months on male and female rats The results showed decreased hippocampal AChE activity in male and females receiving HS and HF diets (HS 24% and 36%; HF 38% and 32%, males and females, respectively; P < 005) The activity in the cerebral cortex was reduced in males (49 and 40%) and females (19 and 17%) (P < 005) on HS and HF diets, respectively In the hypothalamus AChE activity was decreased on HS diet in males (46%) and female (25%) (P < 005) and also on HF diet in males (34%) and females (21%) (P < 005) However, in the cerebellum no changes in AChE activity were observed These results indicate that HS and HF diets produced mainly inhibition in acetylcholine degradation It probably indicates a chronic alteration induced by these diets on the cholinergic system
42 citations
TL;DR: Al3+, Ga3+, and In3+ inhibit PBGS by competing with Zn2+, whereas Tl3+ and In 3+ inhibit bovinePBGS by directly oxidizing essential sulfhydryl groups.
40 citations
TL;DR: It is shown for the first time that exposure to low levels of Hg2+, which resembles occupational exposure toLow levels of mercury, caused a marked increase in NTPDase and AChE activities and the relationship of these alterations with the neurotoxicity of inorganic mercury deserves further studies.
30 citations
TL;DR: The results suggest that NTPDase-like activity shows a different behavior among the vertebrate species and tissues studied and it is proposed thatNTPDase1 is the main enzyme present in this preparation.
Abstract: We investigated NTPDase-like activity [ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases)] in liver and kidney membrane from silver catfish (Rhamdia quelen), chicken (Gallus gallus) and rat (Rattus norvegicus) under different conditions and in the presence of several inhibitors. The cation concentration required for maximal activity was 0.5, 1.5 and 2.0 mM for fish, chicken and rat liver, respectively (with ATP and ADP as substrates). The maximal activity in the kidney was observed at calcium concentrations of 0.5, 2.0, 1.5 mM (ATP) and 0.5, 1.5, 1.0 (ADP) for fish, chickens and rats, respectively. The results showed that the pH optimum for all animals and for the two tissues was close to 8.0. The temperature chosen was 25 degrees C for fish and 36 degrees C for chicken and rat preparations. Ouabain had no effect on the NTPDase-like activity of fish, chickens or rats. NTPDase activity was decreased in the presence of lanthanum in the chicken (ADP) and rat (ATP and ADP) liver. In the kidney, lanthanum inhibited fish ATP and rat ATP and ADP (0.2 mM) hydrolysis. N-ethylmaleimide (NEM) had an inhibitory effect on the kidney of all species at the concentration of 3.0 mM (ADP). Orthovanadate only inhibited fish membrane NTPDase; azide only inhibited the preparation at high concentrations (10 mM) and fluoride inhibited it at 10 mM (fish and chicken) and 5 mM (rat). Trifluoperazine (0.05-0.2 mM) and suramin (0.03-0.3 mM) inhibited NTPDase at all concentrations tested. These results suggest that NTPDase-like activity shows a different behavior among the vertebrate species and tissues studied. Additionally, we propose that NTPDase1 is the main enzyme present in this preparation.
4 citations
TL;DR: Results indicate that the bark extract of "Jambolao" has an inhibitory effect on AChE in the cerebellum and cerebral cortex and an stimulatory effect on striatum, indicating a possible alteration in the functionality of the cholinergic system in such cerebral structures.
Abstract: The present study verified the efficiency of the bark ethanol extract of Syzygium cumini on the cholinergic system of normal and alloxan induced diabetic rats. Thirty-nine female rats were divided in control (C), treated with Syzygium cumini (TS), diabetic (D) and diabetic treated with Syzygium cumini (DS). The activity of acetylcholinesterase (AChE) was analyzed in the following cerebral structures: cerebellum, cortex, striatum and hippocampus. The extract of the bark of Syzygium cumini in the dose of 1g.kg-1 was administered orally daily for a period of thirty days. After this period the extract inhibited the activity of the AChE in the cerebellum and cerebral cortex of the rats in the DS group (P<0.05) as, compared to TS. In the striatum there was a significant increase in the activity of the AChE in rats of the TS group (P<0.01) when compared to the C group, and in the hippocampus there was no significant variation. These results indicate that the bark extract of "Jambolao"has an inhibitory effect on AChE in the cerebellum and cerebral cortex and an stimulatory effect on striatum, indicating a possible alteration in the functionality of the cholinergic system in such cerebral structures.
3 citations