title: Effect of intermittent administration of sustained release isosorbide dinitrate (sr-ISDN) in rats with pressure-overload heart.
abstract: Recent studies have demonstrated the benefits of nitric oxide (NO) on myocardial hypertrophy and myocardial fibrosis. It was suggested that NO has a protective effect on myocardial cell through the neurohormonal system. This effect serves to highlight the important role of NO in maintaining the function and form of heart with chronic heart failure. However, there are no known reports about on the effect of prolonged administration of nitrate on pressure over-load heart. This study was conducted to examine the long-term effect of oral nitrate therapy in rats with pressure-overloaded heart. An abdominal aorta constricted (AC) model of pressure-overloaded heart was created in male Wistar rats. Sustained release isosorbide dinitrate (sr-ISDN) (5 mg/kg once a daily) was administered to the rats once a daily for 12 weeks. The animals were euthanized during the study period, and the heart was collected and weighed. Histopathological examination was performed to evaluate the effect of sr-ISDN on myocardial hypertrophy and fibrosis. The ratio of heart to body weight increased significantly in AC rat and this increase was significantly prevented by sr-ISDN treatment. Histopathological examination showed significant increase in fibrotic area of AC rat compared to sham rat, this increase was inhibited by sr-ISDN treatment. Cardiomyocyte transverse diameter was significantly increased in AC rat compared with sham rat, but this increase tended to decrease by sr-ISDN treatment. In conclusion, intermittent administration with sr-ISDN has mild effect in inhibiting cardiac hypertrophy and marked effect in inhibiting fibrosis due to pressure-overload.
authors.affiliation: Department of Veterinary Surgery, Faculth of Agriculture, Tokyo University of Agriculture and Technology, Fuchushi, Tokyo 183-8509, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Shimamura
authors.forename: Hayato
authors.initials: H
authors.lastname: Endo
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kutsuna
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Hirao
authors.forename: Miki
authors.initials: M
authors.lastname: Shimizu
authors.forename: Ryou
authors.initials: R
authors.lastname: Tanaka
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Yamane
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D001835:Body Weight; D003692:Delayed-Action Preparations; D004195:Disease Models, Animal; D004719:Endomyocardial Fibrosis / Q000473:pathology; D006651:Histocytochemistry; D017379:Hypertrophy, Left Ventricular / Q000188:drug therapy* / Q000473:pathology; D007548:Isosorbide Dinitrate / Q000008:administration & dosage*; D008297:Male; D032383:Myocytes, Cardiac / Q000166:cytology; D020030:Nitric Oxide Donors / Q000008:administration & dosage*; D009929:Organ Size; D051381:Rats; D017208:Rats, Wistar
chemical_list: D003692:Delayed-Action Preparations; D020030:Nitric Oxide Donors; D007548:Isosorbide Dinitrate