TY - JOUR
T1 - Nitric oxide synthase in Entamoeba histolytica
T2 - Its effect on rat aortic rings
AU - Hernández-Campos, María Elena
AU - Campos-Rodríguez, Rafael
AU - Tsutsumi, Victor
AU - Shibayama, Mineko
AU - García-Latorre, Ethel
AU - Castillo-Henkel, Carlos
AU - Valencia-Hernández, Ignacio
N1 - Funding Information:
This work was partially supported by grants from CONACYT and Coordinación General de Posgrado e Investigación del I.P.N. (México). Hernández-Campos is a recipient of scholarship from CONACYT. Campos-Rodrı́guez, Garcı́a-Latorre, and Valencia-Hernández are fellow of COFAA-IPN and EDI. We are indebted to Mr. Alan Larsen and Dr. Rosa Adriana Jarillo-Luna for providing helpful comments and Hermilo Garcı́a-Farfán for technical photographical assistance.
PY - 2003
Y1 - 2003
N2 - NADPH-diaphorase activity has been considered as a nitric oxide synthase (NOS) marker. Therefore, the presence of NADPH-d activity in Entamoeba histolytica suggests that they have NOS activity. The aim of this work was to provide support for this contention. The amebic culture medium or amebic purified proteins induced relaxation of endothelium-denuded rat aortic rings pre-contracted with phenylephrine (10-6M), which was inhibited when the amebas were incubated with NG-monomethyl-L-arginine or aminoguanidine (NOS inhibitors), or by pretreatment of the aortic rings with methylene blue. L-Arginine reverted the L-NAME inhibitory effect. In addition, trophozoites produce NO in culture and they have proteins which were recognized by antibodies specific to NOS and show activity of NO synthase. In conclusion, our results provide evidence about the production of NO by trophozoites. This molecule may be responsible for the relaxation elicited by the amebic culture medium and may participate in the pathogenesis of the invasive amebiasis.
AB - NADPH-diaphorase activity has been considered as a nitric oxide synthase (NOS) marker. Therefore, the presence of NADPH-d activity in Entamoeba histolytica suggests that they have NOS activity. The aim of this work was to provide support for this contention. The amebic culture medium or amebic purified proteins induced relaxation of endothelium-denuded rat aortic rings pre-contracted with phenylephrine (10-6M), which was inhibited when the amebas were incubated with NG-monomethyl-L-arginine or aminoguanidine (NOS inhibitors), or by pretreatment of the aortic rings with methylene blue. L-Arginine reverted the L-NAME inhibitory effect. In addition, trophozoites produce NO in culture and they have proteins which were recognized by antibodies specific to NOS and show activity of NO synthase. In conclusion, our results provide evidence about the production of NO by trophozoites. This molecule may be responsible for the relaxation elicited by the amebic culture medium and may participate in the pathogenesis of the invasive amebiasis.
UR - http://www.scopus.com/inward/record.url?scp=0141638626&partnerID=8YFLogxK
U2 - 10.1016/S0014-4894(03)00133-4
DO - 10.1016/S0014-4894(03)00133-4
M3 - Artículo
SN - 0014-4894
VL - 104
SP - 87
EP - 95
JO - Experimental Parasitology
JF - Experimental Parasitology
IS - 3-4
ER -