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Oral administration of Tempol increases blood flow and improves vasodilator responses in the hind limb circulation of Dahl salt‐sensitive (SS) rats on a low salt diet
Author(s) -
Schmidt James R.,
Lombard Julian H.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a268-a
Subject(s) - hindlimb , vasodilation , blood flow , endocrinology , medicine , sodium nitroprusside , chemistry , superoxide , superoxide dismutase , anesthesia , nitric oxide , oxidative stress , biochemistry , enzyme
This study tested the hypothesis that elevated superoxide levels contribute to impaired blood flow regulation and reduced vascular conductance in the systemic circulation of SS rats. The effect of oral administration of the superoxide dismutase mimetic Tempol (7 days) on vascular reactivity and blood flow responses was evaluated in the hind limb vascular bed of Dahl salt‐sensitive (SS/MCW) rats on a low salt (LS, 0.4% NaCl, Dyets) diet. Male SS rats (20–22 weeks old) maintained on LS diet received either plain drinking water or drinking water containing 2mM Tempol ad libitum. Hind limb blood flow was assessed with a Transonic flow probe positioned on the right iliac artery. Resting flow and blood flows measured during intra‐arterial infusion (0.03 mL/min) of acetylcholine (ACh, 15 μg/min) and the NO donor sodium nitroprusside (SNP, 7.5 μg/min) were significantly greater in SS rats treated with Tempol, compared to untreated controls. These findings suggest that superoxide reduces resting blood flow and impairs vascular relaxation in response to NO‐dependent mechanisms in the hind limb vascular bed of SS rats on a low salt diet. Our findings support previous reports (Drenjancevic‐Peric et al. Hypertension 45:687‐691, 2005) that Tempol restores ACh‐induced dilation in isolated middle cerebral arteries from SS rats maintained on LS diet. [NIH #HL‐29587; #HL‐65289, and #HL‐72920].