Premium
Vestibular effects on relative arterial blood flow to and venous return from the limbs during postural changes of conscious felines
Author(s) -
Yavorcik Kevin J,
Erwin Monica,
Misra Sunil P,
Cotter Lucy A,
Reighard Derek A,
Wilson Timothy D,
Cass Stephen P,
Yates Bill J
Publication year - 2009
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.23.1_supplement.611.5
Subject(s) - medicine , vestibular system , blood flow , vasoconstriction , femoral vein , femoral artery , venous blood , venous return curve , anesthesia , anatomy , cardiology , hemodynamics , radiology
Prior studies showed that vestibular signals influence cardiovascular regulation by eliciting vasoconstriction in the dependent limbs during postural changes. These findings led to the hypothesis that loss of vestibular inputs would exacerbate blood pooling in the body regions below the heart during alterations of body position. We tested this hypothesis by comparing blood flow measured using transit‐time ultrasound technology from the femoral vein and artery in conscious cats subjected to head‐up tilt (HUT) at amplitudes up to 60°. Responses were recorded before and after bilateral ablation of vestibular afferents. Before vestibular lesions, blood flow decreased 24‐35% in the femoral artery by ≈9 sec following 60° HUT, presumably due to vasoconstriction, while venous blood flow decreased 55‐65%. After lesions, arterial blood flow dropped only 0‐14% at the time maximal vasoconstriction previously occurred, while venous blood flow decreased 57‐87%. The alterations were shown to be significant by ANOVA (P<0.05). Because vestibular lesions resulted in more blood flow to the leg in the femoral artery and less venous return in the femoral vein, we concluded that the lesions resulted in hindlimb blood pooling during HUT.