TY - JOUR
T1 - Preserved reflex cutaneous vasodilation in cystic fibrosis does not include an enhanced nitric oxide-dependent mechanism
AU - Wilkins, Brad W.
AU - Martin, Elizabeth A.
AU - Roberts, Shelly K.
AU - Joyner, Michael J.
PY - 2007/6
Y1 - 2007/6
N2 - In humans, vasoactive intestinal peptide (VIP) may play a role in reflex cutaneous vasodilation during body heating. We tested the hypothesis that the nitric oxide (NO)-dependent contribution to active vasodilation is enhanced in the skin of subjects with cystic fibrosis (CF), compensating for sparse levels of VIP. In 2 parallel protocols, microdialysis fibers were placed in the skin of 11 subjects with CF and 12 controls. Lactated Ringer was perfused at one microdialysis site and NG-nitro-L-arginine methyl ester (2.7 mg/ml) was perfused at a second microdialysis site. Skin blood flow was monitored over each site with laser-Doppler flowmetry. In protocol 1, local skin temperature was increased 0.5°C every 5 s to 42°C, and then it maintained at 42°C for ∼45 min. In protocol 2, subjects wore a tube-lined suit perfused with water at 50°C, sufficient to increase oral temperature (T or) 0.8°C. Cutaneous vascular conductance (CVC) was calculated (flux/mean arterial pressure) and scaled as percent maximal CVC (sodium nitroprusside; 8.3 mg/ml). Vasodilation to local heating was similar between groups. The change (Δ%CVCmax) in CVC with NO synthase inhibition on the peak (9 ± 3 vs. 12 ± 5%CVCmax; P = 0.6) and the plateau (45 ± 3 vs. 35 ± 5%CVCmax; P = 0.1) phase of the skin blood flow response to local heating was similar in CF subjects and controls, respectively. Reflex cutaneous vasodilation increased CVC in CF subjects (58±4%CVCmax) and controls (53 ± 4%CVCmax; P = 0.37) and NO synthase inhibition attenuated CVC in subjects with CF (37 ± 6%CVCmax) and controls (35 ± 5%CVCmax; P = 0.8) to a similar degree. Thus the preservation of cutaneous active vasodilation in subjects with CF is not associated with an enhanced NO-dependent vasodilation.
AB - In humans, vasoactive intestinal peptide (VIP) may play a role in reflex cutaneous vasodilation during body heating. We tested the hypothesis that the nitric oxide (NO)-dependent contribution to active vasodilation is enhanced in the skin of subjects with cystic fibrosis (CF), compensating for sparse levels of VIP. In 2 parallel protocols, microdialysis fibers were placed in the skin of 11 subjects with CF and 12 controls. Lactated Ringer was perfused at one microdialysis site and NG-nitro-L-arginine methyl ester (2.7 mg/ml) was perfused at a second microdialysis site. Skin blood flow was monitored over each site with laser-Doppler flowmetry. In protocol 1, local skin temperature was increased 0.5°C every 5 s to 42°C, and then it maintained at 42°C for ∼45 min. In protocol 2, subjects wore a tube-lined suit perfused with water at 50°C, sufficient to increase oral temperature (T or) 0.8°C. Cutaneous vascular conductance (CVC) was calculated (flux/mean arterial pressure) and scaled as percent maximal CVC (sodium nitroprusside; 8.3 mg/ml). Vasodilation to local heating was similar between groups. The change (Δ%CVCmax) in CVC with NO synthase inhibition on the peak (9 ± 3 vs. 12 ± 5%CVCmax; P = 0.6) and the plateau (45 ± 3 vs. 35 ± 5%CVCmax; P = 0.1) phase of the skin blood flow response to local heating was similar in CF subjects and controls, respectively. Reflex cutaneous vasodilation increased CVC in CF subjects (58±4%CVCmax) and controls (53 ± 4%CVCmax; P = 0.37) and NO synthase inhibition attenuated CVC in subjects with CF (37 ± 6%CVCmax) and controls (35 ± 5%CVCmax; P = 0.8) to a similar degree. Thus the preservation of cutaneous active vasodilation in subjects with CF is not associated with an enhanced NO-dependent vasodilation.
KW - Skin blood flow
KW - Thermoregulation
KW - Vasoactive intestinal peptide
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U2 - 10.1152/japplphysiol.00013.2007
DO - 10.1152/japplphysiol.00013.2007
M3 - Article
C2 - 17412796
AN - SCOPUS:34447529260
VL - 102
SP - 2301
EP - 2306
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 6
ER -