Antioxidant diet preserves endothelium-dependent vasodilatation in resistance arteries of hypercholesterolemic rabbits exposed to environmental tobacco smoke.
Environmental tobacco smoke (ETS) has been shown to impair endothelium-dependent vasodilation in vitro. This study was performed to investigate the effect of ETS on acetylcholine (ACh)-mediated blood pressure changes in vivo. Seventeen New Zealand White rabbits were fed a cholesterol diet (0.3%) for 13 weeks. Ten animals were exposed to ETS for 6 h/day, and seven animals were not exposed to ETS (non-ETS). Four of the ETS and three of the non-ETS-exposed rabbits received an antioxidant vitamin diet before and during their cholesterol diet for 21 weeks. Six rabbits served as healthy controls. To determine endothelium-dependent and independent blood pressure (BP) responses, BP was measured through a Tygon catheter, inserted into the right carotid artery at baseline and after each of three incremental intravenous doses of norepinephrine (NE; 1, 4, and 20 microg/kg), ACh (3.3, 10, and 30 microg/kg), and nitroglycerin (NTG; 1, 10, and 40 microg/kg). After NE, BP increases were significantly attenuated in the ETS group (p = 0.001) but not in animals receiving the antioxidant supplement. At both the middle and high ACh concentrations, ETS (p = 0.03 and p = 0.01, respectively) and hypercholesterolemia (p = 0.03 and p = 0.06, respectively) attenuated ACh-induced reductions in BP. At the highest ACh concentration, vitamins enhanced the reduction in BP (p = 0.002) and blocked the effect of ETS (p = 0.04). Neither ETS nor vitamins influenced NTG-induced decreases in BP. A combined antioxidant-vitamin diet can preserve endothelium-dependent vasodilatation in the hypercholesterolemic rabbit exposed to ETS.
Schwarzacher
S P
SP
Cardiology Division, Stanford University, Palo Alto, California, USA.
Hutchison
S
S
Chou
T M
TM
Sun
Y P
YP
Zhu
B Q
BQ
Chatterjee
K
K
Glantz
S A
SA
Deedwania
P C
PC
Parmley
W W
WW
Sudhir
K
K
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D019587:Dietary Supplements; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D006937:Hypercholesterolemia / Q000503:physiopathology*; D005996:Nitroglycerin / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D011817:Rabbits; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D000975:Antioxidants; D014028:Tobacco Smoke Pollution; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D005996:Nitroglycerin; D000109:Acetylcholine; D009638:Norepinephrine