Hyperemic Brachial Artery Blood Flow Velocity

This thesis aims to evaluate the blood flow velocity in the Brachial artery during reactive hyperemia. Primarily to appraise the information it might contain regarding cardiovascular function and cardiovascular risk. Ultrasonographic doppler measurements of the Brachial artery were made on the 1016 men and women aged 70 included in the prospective investigation of the vasculature in Uppsala seniors (PIVUS) study. Analysis of the blood flow velocity in the forearm was made in comparison to established methods of estimating endothelial function, clinical markers of cardiovascular risk, the Framingham risk score and global atherosclerosis determined by whole body magnetic resonance angiography. Systolic blood flow velocity was positively related to cardiovascular risk whereas the diastolic velocity was inversely correlated. However, the systolic to diastolic blood flow velocity (SDFV) ratio was more closely associated with cardiovascular risk than its components apart. Ultrasonographic markers of Carotid atherosclerosis were related to the SDFV ratio. Concentric left ventricular remodeling and left ventricular mass index were also associated with the SDFV ratio, but not to its numerator or denominator separately. A similar pattern was found when assessing SDFV ratio in relation to global atherosclerosis, as well as to established markers of arterial compliance and vasodilation. In conclusion, during reactive hyperemia of the Brachial artery, the systolic to diastolic blood flow velocity ratio appears to contain information of additional value than its components separately, independently of established cardiovascular risk factors. Possibly, the SDFV ratio could offer a promising means to estimate cardiovascular risk in aging populations.PIVU

Hyperemic Brachial Artery Blood Flow Velocity

This thesis aims to evaluate the blood flow velocity in the Brachial artery during reactive hyperemia. Primarily to appraise the information it might contain regarding cardiovascular function and cardiovascular risk. Ultrasonographic doppler measurements of the Brachial artery were made on the 1016 men and women aged 70 included in the prospective investigation of the vasculature in Uppsala seniors (PIVUS) study. Analysis of the blood flow velocity in the forearm was made in comparison to established methods of estimating endothelial function, clinical markers of cardiovascular risk, the Framingham risk score and global atherosclerosis determined by whole body magnetic resonance angiography. Systolic blood flow velocity was positively related to cardiovascular risk whereas the diastolic velocity was inversely correlated. However, the systolic to diastolic blood flow velocity (SDFV) ratio was more closely associated with cardiovascular risk than its components apart. Ultrasonographic markers of Carotid atherosclerosis were related to the SDFV ratio. Concentric left ventricular remodeling and left ventricular mass index were also associated with the SDFV ratio, but not to its numerator or denominator separately. A similar pattern was found when assessing SDFV ratio in relation to global atherosclerosis, as well as to established markers of arterial compliance and vasodilation. In conclusion, during reactive hyperemia of the Brachial artery, the systolic to diastolic blood flow velocity ratio appears to contain information of additional value than its components separately, independently of established cardiovascular risk factors. Possibly, the SDFV ratio could offer a promising means to estimate cardiovascular risk in aging populations.PIVU

Hyperemic Brachial Artery Blood Flow Velocity

This thesis aims to evaluate the blood flow velocity in the Brachial artery during reactive hyperemia. Primarily to appraise the information it might contain regarding cardiovascular function and cardiovascular risk. Ultrasonographic doppler measurements of the Brachial artery were made on the 1016 men and women aged 70 included in the prospective investigation of the vasculature in Uppsala seniors (PIVUS) study. Analysis of the blood flow velocity in the forearm was made in comparison to established methods of estimating endothelial function, clinical markers of cardiovascular risk, the Framingham risk score and global atherosclerosis determined by whole body magnetic resonance angiography. Systolic blood flow velocity was positively related to cardiovascular risk whereas the diastolic velocity was inversely correlated. However, the systolic to diastolic blood flow velocity (SDFV) ratio was more closely associated with cardiovascular risk than its components apart. Ultrasonographic markers of Carotid atherosclerosis were related to the SDFV ratio. Concentric left ventricular remodeling and left ventricular mass index were also associated with the SDFV ratio, but not to its numerator or denominator separately. A similar pattern was found when assessing SDFV ratio in relation to global atherosclerosis, as well as to established markers of arterial compliance and vasodilation. In conclusion, during reactive hyperemia of the Brachial artery, the systolic to diastolic blood flow velocity ratio appears to contain information of additional value than its components separately, independently of established cardiovascular risk factors. Possibly, the SDFV ratio could offer a promising means to estimate cardiovascular risk in aging populations.PIVU

Effects of nine different gastrointestinal polypeptides on vascular smooth muscle in vitro

Nine polypeptides of gastrointestinal origin were tested for their possible effect on vascular smooth muscle of the rat portal vein. The substances tested were bombesin, caerulein, glucagon, insulin, pentagastrin, secretin, somatostatin, substance P and vasoactive intestinal polypeptide (VIP). Cumulative dose-response relations of integrated mechanical activity (mean tension) were obtained with maximal concentrations of the various peptides of 1-10 microgram/ml. Within this concentration range, only substance P and VIP showed clearcut effects; substance P causing contraction and VIP relaxation. The dose of substance P needed to produce contraction was high (ED50 greater than 1 microM) so that the physiological importance of this response is doubtful. On the other hand, ED50 for the relaxing effect of VIP was about 15 nM, which is in accordance with concentrations reported to produce significant vasodilatation in vivo. The results support the view that vascular effects which have been reported to occur in response to the other 7 peptides are mainly of indirect origin and not mediated via direct action on vascular smooth muscle

Role of vasoactive intestinal polypeptide (VIP) in the neurogenic vasodilatation of the portal vein in the rabbit

A coarse network of nerve fibres displaying immunoreactivity for vasoactive intestinal polypeptide (VIP) was found in the wall of the hepatic portal vein of the rabbit. Electrical field stimulation of the rabbit portal vein in vitro, in the presence of adrenergic and cholinergic blockade, caused a marked relaxation of the vessel and a release of VIP into the perfusate. Addition of VIP to the tissue bath elicited a concentration-dependent inhibition of the mechanical activity of the portal vein. The results suggest that VIP containing neurones might participate in the non-cholinergic, non-adrenergic vasodilatation of the portal vein in the rabbit