scholarly journals Cold pressor test using strain-gauge plethysmography

2016 ◽  
Vol 40 (3) ◽  
pp. 410-417 ◽  
Author(s):  
Giacomo Feliciani ◽  
Cristiano Peron ◽  
Augusto La Rocca ◽  
Maria Francesca Scuppa ◽  
Andrea Malavolta ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Resistance ◽  
Strain Gauge ◽  
Healthy Subjects ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Peripheral Vascular Resistance ◽  
Peripheral Vascular ◽  
Pressor Test ◽  
Strain Gauge Plethysmography

This laboratory activity is designed to teach students how to measure forearm muscle blood flow (FBF) to describe the mechanisms of peripheral blood flow thermal regulation in healthy subjects. The cold pressor test (CPT) is the clinical procedure used in the experiment to induce arterial vasoconstriction. Strain-gauge plethysmography is applied on the patient's forearm to noninvasive monitor vasoconstriction effects on local blood perfusion and physiological parameters such as blood pressure (BP) and heart rate (HR). Patients with an altered peripheral vascular resistance (e.g., in hypertension) have different responses to the CPT from healthy subjects. To date, experimental evidence remains unexplained, as we do not know if the BP and HR increase is caused by a decrease in flow rate or an increase in peripheral vascular resistance during the test. To clarify this situation, we have to quantify the parameter we assume is being conditioned by the regulatory physiological intervention, i.e., peripheral vascular resistance. Peripheral vascular resistance quantification can be calculated as the ratio between muscle flow and mean arterial pressure. Students will learn how to apply the instrumental procedure to collect and analyze data before, during, and after the CPT and to describe the physiological responses of the peripheral vascular system to external stressors. They will also learn how to distinguish healthy from pathological responses on the basis of how sympathetic nervous system reactions influence the biomechanics of peripheral vessels.

The effect of steady-state CO2 on regional brain blood flow responses to increases in blood pressure via the cold pressor test

2019 ◽  
Vol 222 ◽  
pp. 102581 ◽  
Author(s):  
Brittney A. Herrington ◽  
Scott F. Thrall ◽  
Leah M. Mann ◽  
Michael M. Tymko ◽  
Trevor A. Day
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Steady State ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Brain Blood Flow ◽  
Pressor Test ◽  
Regional Brain

Cutaneous Vascular Responses Evoked in the Hand by the Cold Pressor Test and by Mental Arithmetic

1990 ◽  
Vol 79 (1) ◽  
pp. 43-50 ◽  
Author(s):  
I. Marriott ◽  
Janice M. Marshall ◽  
E. J. Johns
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Vascular Resistance ◽  
Mental Arithmetic ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Pressor Test ◽  
Contralateral Hand ◽  
The Right ◽  
Cutaneous Vascular Resistance

1. Laser Doppler flowmetry has been used to study changes in cutaneous erythrocyte flux produced in the hand (i) on successive immersion of the contralateral hand in water at 20°C (cold test) and then in water at 0–4°C (cold pressor test), and (ii) by mental arithmetic. 2. In 11 subjects, placing the right hand in water at 20°C for 2 min induced a significant decrease in cutaneous erythrocyte flux in the contralateral hand and a significant fall in mean arterial pressure. Cutaneous vascular resistance, calculated as arterial pressure/cutaneous erythrocyte flux, showed no significant change. Thus, the decrease in erythrocyte flux was apparently due to a fall in perfusion pressure. 3. Subsequent immersion of the right hand in water at 0–4°C for 2 min caused a significant decrease in erythrocyte flux in the contralateral hand and a significant rise in mean arterial pressure. It is concluded that the cold pressor response evoked from one hand elicited a substantial reflex vasoconstriction in the skin of the other hand; accordingly, calculated cutaneous vascular resistance increased significantly. 4. Eight subjects performed mental arithmetic for two periods of 2 min separated by a rest period of 2 min. By the end of the second minute of each period of mental arithmetic there was a significant decrease in erythrocyte flux. Mean arterial pressure increased significantly in the first period only, but calculated cutaneous vascular resistance increased in both periods, consistent with cutaneous vasoconstriction. 5. The cold pressor test and mental arithmetic are aversive stimuli that evoke the characteristic pattern of the alerting or defence response which includes splanchnic vasoconstriction and muscle vasodilatation. Previous studies on the cutaneous vascular component of this response have yielded equivocal results. The present study provides firm evidence that it includes cutaneous vasoconstriction, at least in the hand.

scholarly journals Exercise hyperemia and vasoconstrictor responses in humans with cystic fibrosis

2005 ◽  
Vol 99 (5) ◽  
pp. 1866-1871 ◽  
Author(s):  
William G. Schrage ◽  
Brad W. Wilkins ◽  
Vicki L. Dean ◽  
John P. Scott ◽  
Nancy K. Henry ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cystic Fibrosis ◽  
Blood Flow ◽  
Forearm Blood Flow ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Pressor Test ◽  
Sympathetic Vasoconstriction ◽  
Exercise Hyperemia ◽  
Forearm Exercise

ATP released from circulating erythrocytes is a potential signal regulating muscle blood flow during exercise (exercise hyperemia), and intravascular ATP appears to blunt sympathetic vasoconstriction during exercise. Erythrocytes from patients with cystic fibrosis (CF) do not release ATP. The goal of the present study was to determine whether increases in forearm blood flow during exercise are blunted in CF patients and whether CF patients exhibit greater vasoconstrictor responsiveness during exercise. Nine control subjects and 10 CF patients who were free of other disease complications (∼96% O2 saturation) performed incremental rhythmic forearm exercise at 5, 10, and 15% of maximum handgrip strength for 21 min (7 min at each workload). We used a cold pressor test to evoke sympathetic vasoconstriction under resting conditions and at each exercise workload. As a control, subjects performed a second exercise bout without the cold pressor test. Continuous brachial artery blood velocity was monitored beat-to-beat, and vessel diameter was assessed by Doppler ultrasound. Artery diameter, as well as blood pressure, heart rate, and O2 saturation, was measured at steady-state exercise and at 1 min into the cold pressor stimulus. Blood pressure and heart rate responses to the forearm exercise and each cold pressor test were similar in both groups ( P > 0.05). Contrary to our hypothesis, forearm blood flow ( P = 0.91) and forearm vascular conductance ( P = 0.82) were similar at rest and at each level of exercise between CF patients and controls. Additionally, there was no difference in the degree of sympathetic vasoconstriction between groups at rest and at each level of exercise ( P = 0.22). Our results suggest that ATP released from the deformation of erythrocytes is not an obligatory signal for exercise hyperemia in human skeletal muscle.

scholarly journals Splenic Blood Flow Increases after Hypothermic Stimulus (Cold Pressor Test): A Perfusion Magnetic Resonance Study

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Nicola Galea ◽  
Giulia Cundari ◽  
Cristian Borrazzo ◽  
Giacomo Pambianchi ◽  
Angelica Bracci ◽  
...  
Keyword(s):  
Blood Flow ◽  
Magnetic Resonance ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Normal Subjects ◽  
Perfusion Magnetic Resonance Imaging ◽  
Diagnostic Strategy ◽  
Cold Stimulation ◽  
Splenic Blood Flow ◽  
Pressor Test

The Cold Pressor Test (CPT) is a novel diagnostic strategy to noninvasively assess the myocardial microvascular endothelial-dependent function using perfusion magnetic resonance imaging (MRI). Spleen perfusion is modulated by a complex combination of several mechanisms involving the autonomic nervous system and vasoactive mediators release. In this context, the effects of cold temperature on splenic blood flow (SBF) still need to be clarified. Ten healthy subjects were studied by MRI. MRI protocol included the acquisition of GRE T1-weighted sequence (“first pass perfusion”) during gadolinium administration (0.1mmol/kg of Gd-DOTA at flow of 3.0 ml/s), at rest and after CPT. Myocardial blood flow (MBF) and SBF were measured by applying Fermi function deconvolution, using the blood pool input function sampled from the left ventricle cavity. MBF and SBF values after performing CPT were significantly higher than rest values (SBF at rest: 0.65 ± 0.15 ml/min/g Vs. SBF after CPT: 0.90 ± 0.14 ml/min/g, p: <0.001; MBF at rest: 0.90 ± 0.068 ml/min/g Vs. MBF after CPT: 1.22 ± 0.098 ml/min/g, p<0.005). Both SBF and MBF increased in all patients during the CPT. In particular, the CPT-induced increase was 43% ± 29% for SBF and 36.5% ± 17% for MBF. CPT increases SBF in normal subjects. The characterization of a standard perfusion response to cold might allow the use of the spleen as reference marker for the adequacy of cold stimulation during myocardial perfusion MRI.

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