title: A comparative study of the effects of molsidomine and 3-morpholinosydnonimine on the redox status of rat erythrocytes and reticulocytes.
abstract: After enzymic biotransformation, molsidomine (MO) acts via the metabolite 3-morpholinosydnonimine (SIN-1) through spontaneous liberation of nitric oxide (NO) and superoxide (O(2)(.-)). The aim of this study was to compare the effects of MO and its active metabolite SIN-1 on the redox status of rat erythrocytes and reticulocytes. Rat erythrocyte as well as reticulocyte-rich red blood cell (RBC) suspensions were aerobically incubated (2 h, 37 degrees C) without (control) or in the presence of different concentrations of MO or SIN-1. In rat erythrocytes, biotransformation of MO resulted in the production of NO and nitroxyl (NO(-)). Endogenous superoxide anion (O(2)(.-)) participated in peroxynitrite generation. SIN-1 simultaneously liberated NO and O(2)(.-), which formed peroxynitrite (at least in part), but the liberated NO predominantly reacted with haemoglobin, forming methaemoglobin in erythrocytes. In reticulocytes, MO and SIN-1 caused an increase in the levels of both nitrite and 3-nitrotyrosine (an indicator of peroxynitrite), whereas they decreased the level of O(2)(.-). In reticulocytes, MO was metabolized into SIN-1 which led to the generation of NO, which reacted with O(2)(.-) (endogenous or exogenous) forming reactive nitrogen species. In conclusion, there are two metabolic pathways for MO biotransformation: one causing NO and NO(-) generation predominantly in erythrocytes and the other, via SIN-1 metabolism, in reticulocytes. The main difference between the action of MO and SIN-1 was that the latter caused oxidative damage in RBCs.
authors.affiliation: Institute of Biology and Ecology, Faculty of Science, University of Kragujevac, 34000 Kragujevac, Serbia and Montenegro. smarkovic@kg.ac.yu
authors.forename: Snezana D
authors.initials: SD
authors.lastname: Marković
authors.forename: Miroslava Dj
authors.initials: MDj
authors.lastname: Vukajlović
authors.forename: Branka I
authors.initials: BI
authors.lastname: Ognjanović
authors.forename: Andras S
authors.initials: AS
authors.lastname: Stajn
authors.forename: Radoslav V
authors.initials: RV
authors.lastname: Zikić
authors.forename: Zorica S
authors.initials: ZS
authors.lastname: Saicić
authors.forename: Ratko M
authors.initials: RM
authors.lastname: Radojicić
authors.forename: David R
authors.initials: DR
authors.lastname: Jones
authors.forename: Mihajlo B
authors.initials: MB
authors.lastname: Spasić
mesh_terms: D000818:Animals; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism*; D008981:Molsidomine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D026361:Reactive Nitrogen Species / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012156:Reticulocytes / Q000187:drug effects* / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; C002385:linsidomine; D008981:Molsidomine