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Heterogeneous venoconstriction in human lower legs
Author(s) -
Phillips Christien,
Horsburgh J,
Balanos G,
Brown M D
Publication year - 2008
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.22.1_supplement.1211.3
Subject(s) - constriction , medicine , plethysmograph , anatomy , vein , cuff , popliteal vein , lower limbs venous ultrasonography , thigh , great saphenous vein , anesthesia , cardiology , surgery , deep vein , thrombosis
Sympathoexcitation reduces venous capacity in the lower leg, based on volume‐pressure relationships of the whole limb during venous congestion. Whether conduit leg veins contribute to this by active constriction has been a matter of debate. Using Doppler ultrasound, we compared responses to a cold pressor test (CPT) of two lower leg veins, the long saphenous (LS) and popliteal (Pop), against that of the whole limb. Calf venous volume (strain gauge plethysmography) was measured in 10 males (26±4 y, 23±2 BMI, mean ± SD) during venous congestion (thigh cuff 50 mmHg, 5 min) while either the LS or Pop vein were imaged longitudinally 5–7 cm below the knee and diameter measured by edge‐detection software. The CPT, applied between min 3 and 4 of congestion, increased mean arterial pressure and heart rate similarly during imaging of LS and Pop (22±3 and 18±3 mmHg, 14±2 and 11±3 bpm respectively, mean ± SEM). It reduced calf volume by 16±6 %, and the cross‐sectional area (CSA) of the LS (filled diameter 3.0±0.3 mm) decreased by 25±6 % (p<0.01). When imaging Pop vein (diameter 9.4±0.8 mm), CPT also reduced calf volume by 16±3 % but Pop CSA did not alter (+4.0±2.4 %, NS). These disparate vein responses despite the similar sympathoexcitatory challenge imply that changes in whole limb volume will reflect constriction in a superficial (LS) but not deep (Pop) conduit vein as well as smaller post‐capillary venules.