
Type: Artigo de periódico
Title: Bay 41-2272, A Soluble Guanylate Cyclase Stimulator, Relaxes Isolated Human Ureter In A Standardized In Vitro Model.
Author: Miyaoka, Ricardo
Mendes, Camila
Schenka, André
Gonzalez, Paulo Gabriel
de Nucci, Gilberto
Antunes, Edson
Monga, Manoj
Levi D'Ancona, Carlos Arturo
Mónica, Fabíola Zakia
Abstract: To characterize the relaxation induced by BAY 41-2272 in human ureteral segments. Ureter specimens (n = 17) from multiple organ human deceased donors (mean age 40 ± 3.2 years, male/female ratio 2:1) were used to characterize the relaxing response of BAY 41-2272. Immunohistochemical analysis for endothelial and neuronal nitric oxide synthase, guanylate cyclase stimulator (sGC) and type 5 phosphodiesterase was also performed. The potency values were determined as the negative log of the molar to produce 50% of the maximal relaxation in potassium chloride-precontracted specimens. The unpaired Student t test was used for the comparisons. Immunohistochemistry revealed the presence of endothelial nitric oxide synthase in vessel endothelia and neuronal nitric oxide synthase in urothelium and nerve structures. sGC was expressed in the smooth muscle and urothelium layer, and type 5 phosphodiesterase was present in the smooth muscle only. BAY 41-2272 (0.001-100 μM) relaxed the isolated ureter in a concentration dependent manner, with a potency and maximal relaxation value of 5.82 ± 0.14 and 84% ± 5%, respectively. The addition of nitric oxide synthase and sGC inhibitors reduced the maximal relaxation values by 21% and 45%, respectively. However, the presence of sildenafil (100 nM) significantly potentiated (6.47 ± 0.10, P <.05) this response. Neither glibenclamide or tetraethylammonium nor ureteral urothelium removal influenced the relaxation response by BAY 41-2272. BAY 41-2272 relaxes the human isolated ureter in a concentration-dependent manner, mainly by activating the sGC enzyme in smooth muscle cells rather than in the urothelium, although a cyclic guanosine monophosphate-independent mechanism might have a role. The potassium channels do not seem to be involved.
Subject: Adult
In Vitro Techniques
Muscle Relaxation
Muscle, Smooth
Citation: Urology. v. 83, n. 1, p. 256.e1-7, 2014-Jan.
Rights: fechado
Identifier DOI: 10.1016/j.urology.2013.09.005
Address: http://www.ncbi.nlm.nih.gov/pubmed/24231204
Date Issue: 2014
Appears in Collections:Unicamp - Artigos e Outros Documentos

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