Ventricular hypertrophy and arterial hemodynamics following deprivation of nitric oxide in rats.
In the present study, we elucidated the possible role of hemodynamic parameters and chemical factors in the development of ventricular hypertrophy (VH) following chronic nitric oxide (NO) deprivation with Nomega-nitro-L-arginine methyl ester (L-NAME). Impedance spectral analysis was used to obtain the arterial hemodynamics including the steady and pulsatile components. Body weight (BW), left ventricular (LV) weight (LVW), LVW/BW ratio, LV collagen volume fraction (LVCVF), cyclic GMP, and nitrite/nitrate were measured. The extent of VH was evaluated by the LW/BW, total number, numerical density, and size of cardiomyocytes. Sprague-Dawley rats were given L-NAME 10, 20, and 40 mg/kg/day from the age of 10 to 18 weeks. Control and age-matched rats were given vehicle for the same period. Treatment of L-NAME for 8 weeks caused a dose-dependent increase in tail cuff pressure and a reduction in BW with increases in LVW, LVW/BW, number, numerical density, and size of myocytes. There was elevation of aortic pressure with decreases in cardiac output, and arterial compliance. The total peripheral resistance, characteristic impedance and pulse wave reflection were increased. Histological finding revealed severe myocardial hypertrophy and fibrosis with fibroblast infiltration. The LVCVF was increased, while LV cGMP and nitrite/nitrate were reduced in a dose-dependent manner. The results suggest that chronic NOS blockade causes hypertension, impairment of large vessel properties, and VH. The development of VH may result partly from the decreases in cGMP and nitrite/nitrate in the ventricle. Correlation analysis indicates that the extent of VH is equally related to the steady and pulsatile hemodynamics.
Hu
Cheng-Tao
CT
Adlink Technology Inc., Taipei, Taiwan.
Chang
Huai-Ren
HR
Hsu
Yung-Hsiang
YH
Liu
Chia-Jui
CJ
Chen
Hsing I
HI
D000465:Algorithms; D000818:Animals; D001158:Arteries / Q000503:physiopathology*; D001835:Body Weight / Q000187:drug effects; D006332:Cardiomegaly / Q000473:pathology / Q000503:physiopathology*; D002452:Cell Count; D003094:Collagen / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D004562:Electrocardiography / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006439:Hemodynamics / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000473:pathology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000502:physiology*; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology
D004791:Enzyme Inhibitors; D009566:Nitrates; D009569:Nitric Oxide; D003094:Collagen; D052250:Nitric Oxide Synthase Type III; D006152:Cyclic GMP; D019331:NG-Nitroarginine Methyl Ester