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Angeli,J.K.; Ramos,D.B.; Casali,E.A.; Souza,D.O.G.; Sarkis,J.J.F.; Stefanon,I.; Vassallo,D.V.; Fürstenau,C.R.. |
Gadolinium (Gd) blocks intra- and extracellular ATP hydrolysis. We determined whether Gd affects vascular reactivity to contractile responses to phenylephrine (PHE) by blocking aortic ectonucleoside triphosphate diphosphohydrolase (E-NTPDase). Wistar rats of both sexes (260-300 g, 23 females, 7 males) were used. Experiments were performed before and after incubation of aortic rings with 3 µM Gd. Concentration-response curves to PHE (0.1 nM to 0.1 mM) were obtained in the presence and absence of endothelium, after incubation with 100 µM L-NAME, 10 µM losartan, or 10 µM enalaprilat. Gd significantly increased the maximum response (control: 72.3 ± 3.5; Gd: 101.3 ± 6.4%) and sensitivity (control: 6.6 ± 0.1; Gd: 10.5 ± 2.8%) to PHE. To investigate the blockade... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gadolinium; E-NTPDase; Adenosine; Angiotensin II; AT1receptor. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000500010 |
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Casali,E.A.; Silva,T.R. da; Gelain,D.P.; Kaiser,G.R.R.F.; Battastini,A.M.O.; Sarkis,J.J.F.; Bernard,E.A.. |
Sertoli cells have been shown to be targets for extracellular purines such as ATP and adenosine. These purines evoke responses in Sertoli cells through two subtypes of purinoreceptors, P2Y2 and P A1. The signals to purinoreceptors are usually terminated by the action of ectonucleotidases. To demonstrate these enzymatic activities, we cultured rat Sertoli cells for four days and then used them for different assays. ATP, ADP and AMP hydrolysis was estimated by measuring the Pi released using a colorimetric method. Adenosine deaminase activity (EC 3.5.4.4) was determined by HPLC. The cells were not disrupted after 40 min of incubation and the enzymatic activities were considered to be ectocellularly localized. ATP and ADP hydrolysis was markedly increased by... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sertoli cells; Purine nucleotides; ATP diphosphohydrolase; Ecto-5'-nucleotidase; Ectoadenosine deaminase. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001001000003 |
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