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At least 343 records · Page 19Linked to original sources
PubMed1993

Effects of norepinephrine on endothelium-dependent vasodilation of forearm resistance vessels.

BACKGROUND: Endothelium-dependent dilatation of forearm resistance vessels is attenuated in patients with heart failure. Activation of the sympathetic nervous system could cause this abnormality by way of vasoconstriction and chemical inactivation of nitric oxide. METHODS AND RESULTS: The effects of concurrent intra-arterial norepinephrine infusions (25, 50 and 100 ng/min) on forearm blood flow responses to equipotent doses of an endothelium-dependent vasodilator, methacholine (0.3 and 1.5 micrograms/min), and an endothelium-independent vasodilator, nitroprusside (1 and 5 micrograms/min), were studied in 12 normal subjects. Norepinephrine infusions increased the mean plasma norepinephrine from 255 pg/ml at baseline to 460, 629, and 1089 pg/ml, respectively. Basal forearm blood flow was reduced from 2.9 to 1.6 ml/min/100 ml of forearm volume at the highest dose (p < 0.01). The average response to the lowest dose of methacholine (4.5 ml/min/100 ml) was not significantly reduced by concurrent infusion of norepinephrine (4.4, 4.2, and 4.3 ml/min/100 ml, respectively), whereas the response to the higher dose of methacholine (8.9 ml/min/100 ml) tended to be lower (7.2, 6.7, and 7.4 ml/min/100 ml, respectively) but did not attain statistical significance. Methacholine induced vasodilation was not more sensitive to norepinephrine than nitroprusside responses. Lower body negative pressure (-20 mm Hg) also significantly reduced baseline forearm flow and increased plasma norepinephrine but did not effect either methacholine or nitroprusside induced vasodilation. CONCLUSION: Sympathetic stimulation induced by infusion of norepinephrine or lower body negative pressure is not a potent antagonist to endothelium-dependent vasodilation of the forearm vasculature. These data suggest that sympathetic activation does not completely explain the abnormal endothelium-dependent vasodilation seen in patients with heart failure.

Adult↗
PubMed1999

Acute hyperglycaemia in the forearm induces vasodilation that is not modified by hyperinsulinaemia.

OBJECTIVE: To evaluate whether acute elevations of local plasma glucose concentrations could influence forearm blood flow (FBF) and how this interacts with local hyperinsulinaemia in healthy volunteers. METHODS: Using the perfused forearm technique, in random order, glucose 20% or saline 0.9% as a control was infused in three dose steps (0.3, 1.0, and 3.0 ml/min) for 5 min each in eight healthy men. The infusion experiments were repeated, in random order, during local hyperinsulinaemia by intra-arterial infusion of insulin 0.05 mU/kg/min. The ratio of FBF of the infused over the FBF in the control arm (FR) was measured at 15-sec intervals during the infusions. RESULTS: Glucose infusion increased the FR dose-dependently by 172%+/-39% (M+/-SE) at the highest dose (P < 0.01). During hyperinsulinaemia the glucose-induced increase in FR was significantly (P < 0.01) less, 96%+/-26%, however, when changes in FR or forearm vascular resistance were related to the plasma glucose concentrations both glucose infusions were equipotent. The saline infusions induced small increases in FR of 27+/-5% (P < 0.01) and 24+/-11% (P > 0.05), without or with insulin respectively. The changes in FR during the saline infusions were much smaller than during the glucose infusions (P < 0.01). During the glucose infusions small but significant increases in FBF and venous plasma glucose in the non-infused forearm appeared, indicating carry-over effect and the possibility of a very low threshold for glucose-induced vascular effects. CONCLUSIONS: High, local levels of glucose in the forearm have a vasodilator effect on resistance vessels in skeletal muscle of the forearm that is not modified by local hyperinsulinaemia. Indications were found that the threshold for this glucose-induced vasodilation may be remarkably low, but this needs to be studied more formally.

Acute Disease↗
PubMed1990

Physiological levels of plasma non-esterified fatty acids impair forearm glucose uptake in normal man.

1. The purpose of the present study was to maintain physiological plasma non-esterified fatty acid levels and to (i) examine their effect on skeletal muscle insulin-stimulated glucose uptake and metabolite exchange using the forearm technique, and (ii) evaluate their effect on whole-body glucose uptake and fuel oxidation. 2. Intralipid (10%) and heparin (Lipid) or saline (Control) was administered to eight healthy male subjects on separate occasions for 210 min. Insulin, glucagon and somatostatin were administered from 60 to 210 min in each study and euglycaemia was maintained. 3. Plasma non-esterified fatty acid levels plateaued at 420 +/- 50 mumol/l with the Lipid infusion but were completely suppressed during the Control clamp. Forearm non-esterified fatty acid uptake increased with the Lipid infusion (+50 +/- 10 nmol min-1 100 ml-1 of forearm) and was accompanied by a significant decrease in forearm glucose uptake (+3.23 +/- 0.25 versus +3.65 +/- 0.35 mumol min-1 100 ml-1 of forearm, Lipid and Control, respectively; P less than 0.05) and alanine release (-84 +/- 12 versus -113 +/- 15 nmol min-1 100 ml-1 of forearm, Lipid and Control, respectively; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Arginine vasopressin attenuates phenylephrine-induced forearm vasoconstriction in men.

1. The aim of this study was to examine whether arginine vasopressin modulates the vasoconstricting action of phenylephrine in human forearms. 2. In seven healthy subjects, we determined the percentage increases in forearm vascular resistance evoked by intra-arterial infusion of phenylephrine at graded doses during simultaneous intra-arterial infusion of saline or arginine vasopressin at two doses. Similarly, in another seven subjects, we examined the effects of intra-arterial infusions of saline or angiotensin II on the vasoconstricting action of intra-arterial phenylephrine. 3. Arginine vasopressin and angiotensin II caused small, but insignificant, increases in baseline forearm vascular resistance. Arginine vasopressin at the two doses significantly attenuated the percentage increases in forearm vascular resistance evoked with phenylephrine at graded doses. Angiotensin II did not alter the forearm vascular responses to phenylephrine. 4. Intra-arterial infusion of arginine vasopressin at doses of 0.6 and 1.8 ng/min raised the plasma arginine vasopressin concentration in the venous effluents from 1.6 +/- 0.3 (control) to 4.0 +/- 0.9 and to 16.4 +/- 6.9 pg/ml, respectively. 5. These results suggest that arginine vasopressin at physiological concentrations with a minimal direct effect on resistance arteries attenuates the vasoconstricting action of phenylephrine in human forearms.

Adolescent↗
PubMed1994

Forearm substrate utilization during exercise after a meal containing both fat and carbohydrate.

1. Whilst the provision of exogenous carbohydrate has been shown to be beneficial to endurance exercise performance, little attention has been paid to the possibility of dietary manipulation of the availability of fat. 2. Ten normal subjects were studied on two occasions: after an overnight fast (postabsorptive state) and after a meal containing 80 g of fat and 80 g of carbohydrate (fed state). Forearm substrate exchange was studied during 60 min of isometric forearm exercise (5 s contraction, 5 s relaxation). 3. In the fed state concentrations of plasma triacylglycerol (1510 +/- 150 versus 850 +/- 80 mumol/l, P < 0.01), blood ketone bodies (151 +/- 21 versus 80 +/- 10 mumol/l, P < 0.01) and plasma insulin (17 +/- 3 versus 7 +/- 1 m-units/l, P < 0.01) were elevated compared with the postabsorptive state; plasma glucose and non-esterified fatty acid concentrations were not significantly different. 4. Forearm blood flow and O2 consumption each increased about 6-fold during exercise, with no differences between the two nutritional states. The potential contribution of individual substrates to forearm O2 consumption (a calculation which is independent of blood flow) was assessed: for triacylglycerol it was significantly greater in the fed state (P < 0.01). The sum of the potential contributions of triacylglycerol, non-esterified fatty acids, glucose and ketone bodies to forearm O2 consumption was significantly greater, both before and during exercise, in the fed than in the postabsorptive state (P < 0.05), implying the sparing of endogenous (forearm) fuels. 5. These studies highlight the potential for manipulation of substrate supply during exercise by feeding meals containing both carbohydrate and fat.

Adult↗
PubMed1998

How reproducible is bilateral forearm plethysmography?

AIMS: In studies using strain-gauge forearm plethysmography to measure changes in forearm blood flow (FBF) during intra-arterial infusions of vasoactive substances, measurements are often made in both arms simultaneously and the change in ratio of the infused and control arms used to express responses. However, the reproducibility of bilateral plethysmography in this setting has not been addressed in published studies. The unilateral technique remains in use, and forearm vascular resistance (FVR), an alternative method of expressing responses, is used by some investigators. We have assessed: (a) the intra-subject variability of bilateral FBF measurements (FBF ratios) at rest, after unilateral forearm exercise, and during intra-arterial infusions of vasoconstrictor substances; (b) whether bilateral plethysmography is more reproducible than unilateral plethysmography; and (c) the reproducibility of FVR (unilateral and bilateral). METHODS: Study 1 Nine healthy subjects attended 3 study days, 1 week apart. FBF was measured at rest and after 2 min of standardized unilateral forearm exercise; between-day intra-subject variability was expressed as coefficients of variation (CV) calculated using two-way analysis of variance (ANOVA). Study 2 Five healthy subjects attended 2 study days when FBF was measured during incremental infusions of noradrenaline (15, 30, 150, 300 pmol min[-1]) and angiotensin II (1, 5, 10, 50 pmol min[-1]); for each individual subject at each dose intra-subject variability was assessed using the difference between responses (percentage change from baseline) on days 1 and 2. RESULTS: Study 1 At rest, intra-subject variability (CV) of baseline FBF ratios was 19% compared with 31% (left) and 39% (right) for unilateral FBF measurements. After ipsilateral exercise, unilateral FBF measurements were more reproducible (32 vs 17%) than FBF ratios; by 20 min after exercise, the previous pattern had been re-established (19 vs 27%). Intra-subject variability (CV) of baseline FVR ratio and post-exercise FVR was 14%. Study 2 Inter-quartile ranges of the differences between responses on days 1 and 2 (FBF ratios vs FBF) were: angiotensin II 14 vs 18%; noradrenaline 16 vs 27%. CONCLUSIONS: FBF ratios are more reproducible than unilateral FBF measurements at rest (CV 19% vs 39%) and for measuring responses to intra-arterial infusions of vasoconstrictor substances. FVR may have a small reproducibility advantage. Non-experimental stimuli can cause significant and misleading changes in measured responses if unilateral measurements are used; it is therefore recommended that responses to intra-arterial infusions should be measured using bilateral forearm plethysmography with the results expressed as FBF ratios.

Angiotensin II↗
PubMed2001

Ageing impairs insulin-mediated vasodilatation but not forearm glucose uptake.

BACKGROUND: It is unclear if insulin-mediated vasodilatation is altered by ageing and if this affects insulin-mediated glucose uptake. MATERIAL AND METHODS: A 2-h euglycaemic hyperinsulinaemic clamp (56 mU m(-2) min(-1)) was performed in 10 healthy, nonobese elderly men (70-75 years) and 13 young men (23-28 years). Forearm blood flow (FBF) was measured by venous occlusion plethysmography and forearm glucose uptake was calculated by arterial and venous serum glucose determinations in the forearm. RESULTS: Insulin induced an increase in FBF in the younger men (from 3.9 +/- 1.1 SD to 5.9 +/- 2.2 mL min(-1) 100(-1)mL tissue, P < 0.001), but this insulin-mediated vasodilatation was completely blunted in the elderly subjects. Glucose extraction during the clamp was significantly higher in the elderly subjects (1.2 +/- 0.76 vs. 0.82 +/- 0.37 mmol L(-1) at 120 min, P < 0.01), resulting in a similar forearm glucose uptake in the two groups. On the other hand, whole-body glucose uptake was significantly decreased in the elderly subjects (5.3 +/- 1.8 vs. 8.0 +/- 1.1 mg kg(-1) min(-1), P < 0.001). CONCLUSION: The present study showed that the ability of insulin to induce vasodilatation is blunted in the forearm in healthy, nonobese elderly subjects. However, the elderly compensate for this impairment with an increased glucose extraction from arterial blood to maintain an unaltered forearm glucose uptake.

Adult↗
PubMed2001

Role of angiotensin type 2 receptors in human forearm vascular responses of normal volunteers.

1. It has been hypothesized that the expression of angiotensin (Ang) II type 2 (AT(2)) receptors may become important in vascular disease; however, the functional existence of AT(2) receptors in normal adult humans remains to be established. 2. Vascular responses to AngII after the administration of the specific AT(2) receptor antagonist PD 123319 were determined in the forearm circulation of normal volunteers. 3. PD 123319 (8 microg/min) did not alter basal forearm blood flow, or forearm blood flow or forearm vascular resistance responses to AngII. 4. These results suggest that AT(2) receptors do not play a significant role in the regulation of forearm blood flow or forearm vascular resistance of normal volunteers, but do not preclude a role for AT(2) receptors in other vascular beds or in patients with cardiovascular disease.

Adult↗
PubMed2002

Mixed median nerve forearm conduction velocity in the presence of focal compression neuropathy at the wrist versus peripheral neuropathy.

OBJECTIVES: To establish normal values for the conduction velocity of the mixed median nerve in the forearm, and to determine the use of mixed median nerve conduction velocity (NCV) studies across the forearm in the differential diagnosis of carpal tunnel syndrome (CTS), peripheral neuropathy, and CTS with peripheral neuropathy. DESIGN: Criterion standard. Mixed median NCV studies across the forearm were added to routine CTS investigational protocols. SETTING: University outpatient setting, rural referral base. PARTICIPANTS: Thirty healthy volunteers and 60 patients referred with symptoms and signs suggestive of CTS and/or peripheral neuropathy. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Motor sensory and mixed median nerve conduction velocity across the forearm. RESULTS: The mean mixed median NCV across the forearm was 64.5 m/s in healthy subjects and subjects with CTS. The mean mixed NCV in subjects with peripheral neuropathy was 54 m/s, even in the presence of CTS. CONCLUSION: Mixed median NCV in the forearm added to the standard protocols is helpful in differentiating the diagnosis of CTS from peripheral neuropathy and CTS with peripheral neuropathy.

Adult↗
PubMed2003

Modeled evidence of force reduction at the extensor carpi radialis brevis origin with the forearm support band.

PURPOSE: Although the forearm support band has been hypothesized to reduce force and thus inflammation and degeneration at the extensor carpi radialis brevis (ECRB) origin, little evidence exists to support an actual effect. We present both a cadaveric and clinical model that show the effect and principles of the forearm support band. METHOD: The cadaver model measured forces at the ECRB origin as various pressures were applied to the forearm support band and while the ECRB tendon was loaded distally. For clinical correlation support band pressure during rest and activity was measured in healthy individuals. RESULTS: Our results revealed an increased forearm support band effect with increased band pressure and a decreased relative effect with increased force applied distally. For clinical correlation the support band pressure during activity was measured in 21 healthy volunteers while controlling for the application pressure in 2 common support band designs. This resulted in activity pressures ranging from 43 to 192 mm Hg dependent on the starting pressure of application. CONCLUSIONS: Although further clinical evaluation is necessary to determine the most appropriate clinical indications and application pressures for the forearm support band these combined results suggest that the forearm support band may be most effective when applied to 30 to 50 mm Hg at rest, resulting in up to 120 mm Hg pressure during activity. According to our model this would result in a force reduction at the ECRB origin of approximately 13% to 15% throughout a range of activity levels.

Adult↗
PubMed2002

A comparison of the donor-site morbidity after using the prelaminated fasciomucosal flap and the fasciocutaneous radial forearm flap for intraoral reconstruction.

Since 1996 we have performed mucosal prelamination of the distal radial forearm flap for functional reconstruction of defects of the intraoral lining. This study was undertaken to demonstrate that the prelaminated fasciomucosal radial forearm flap can provide physiological oropharyngeal reconstruction with mucus-producing tissue, while avoiding the donor-site complications of the fasciocutaneous radial forearm flap. We examined the donor hand at least 6 months postoperatively in 20 patients after using a prelaminated fasciomucosal radial forearm flap and in 15 patients after harvesting a classical fasciocutaneous radial forearm flap. The evaluation of hand function included range of motion, grip power, pinch power, sensibility and vascular analysis in both hands. The patients were asked about cold intolerance, pain and any restrictions in daily life, and the cosmetic appearance of the donor hand was noted. In the prelaminated-flap group (n 20), two patients had decreased wrist extension, and one of these patients also had reduced strength and mild hypaesthesia in the donor hand. In the classical-fasciocutaneous-flap group (n 15), six patients had decreased wrist extension, five patients had reduced strength and four patients had diminished sensibility in the donor hand. Painful neuromas were found only after fasciocutaneous flaps (three cases). Subjective assessment revealed restricted hand function in one patient in the prelaminated-flap group, and in five patients who had undergone fasciocutaneous flap transfer. The results of this study show that using the prelaminated fasciomucosal radial forearm flap minimises the donor-site morbidity. Furthermore, we were able to improve the cosmetic appearance of this very exposed region.

Adult↗
PubMed2002

An unusual anomaly of the radial artery with potential significance to the forearm free flap. Case report.

INTRODUCTION: The radial forearm free flap has become the favourite transplant for microsurgical repair of small-to-medium sized soft tissue defects of the oral cavity. This flap derives its blood supply from perforators of the radial artery. As the radial forearm flap gains ever more popularity, it is likely that anomalous forearm vascular patterns will be encountered by more surgeons. PURPOSE: In this paper, a rare anomaly found in a patient during flap elevation is described. This 63-year-old male had a squamous cell carcinoma of the floor of the mouth and a radial forearm free flap was harvested to repair the defect. During this procedure an aberrant duplication of the radial artery was found which could have significance in harvesting such a flap in other patients. CONCLUSION: There are anomalies of the radial artery that may jeopardize the vascular supply to the radial forearm free flap. Surgeons performing this flap must be aware of the most common variants of the vascular anatomy of the forearm.

Anastomosis, Surgical↗
PubMed2001

[Defect coverage of the hand and forearm with a free scapula-parascapula flap].

BACKGROUND: Complex defects of the forearm and hand are associated with the loss of important structures. Single-stage reconstruction of these defects requires composite tissue transplantations. The subscapular region offers various components for the coverage of complex defects. The scapular and the parascapular flaps can be used each as cutaneous, fasciocutaneous and osteocutaneous or as a combined flap as well. The purpose of this study was to present our experience with the combined scapular-parascapular free flap for defect coverage of the forearm and hand in 13 patients. PATIENTS AND METHOD: Evaluation of 12 patients who underwent coverage of forearm and hand defects with the combined scapular-parascapular free flap during a five-year period. Other treatment options are discussed. RESULTS: Average age of the patients was 39 years, there were ten male and two female patients. Average follow-up was 20 months. Eleven patients suffered from massive trauma, one patient from severe infection of the forearm and hand. The defect size varied from 12 x 8 cm to 45 x 20 cm. In nine cases, a cutaneous and/or fasciocutaneous scapular-parascapular flap was used, two patients underwent defect coverage with an osteocutaneous scapular-parascapular flap, and in one patient, a "four-flap-mega-flap" was transplanted. One flap developed a partial necrosis. Eight patients developed a good or very good functional outcome with their hand and forearm, two patients have a moderate degree of disability. Two patients can use their hand as a supporting hand. CONCLUSION: This study demonstrates that the combined scapular-parascapular free flap is a reliable treatment choice for early coverage of defects of the forearm and hand. The advantages are the long, large and consistent vascular pedicle, the possibility of combination with other flaps and "custom-tailoring", including whatever component is necessary to close the particular defect.

Adult↗
PubMed2001

A mechanical study of the moment-forces of the supinators and pronators of the forearm.

We determined the torque generated by the muscles rotating the forearm at varying degrees of pronation and supination. We used 8 human cadaveric upper extremity specimens with the humerus and ulna rigidly fixed with the elbow in 90 degrees of flexion, while free rotation of the radius around the ulna was allowed. The tendons of the flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), supinator, biceps, pronator teres (PT), and the pronator quadratus' (PQ) superficial and deep heads were isolated. After locking the forearm at intervals of 10 degrees from 90 degrees of pronation to 90 degrees of supination, we loaded each muscle/tendon with a ramp profile. We found that the biceps and supinator are both active supinators, the biceps generating four times more torque with the forearm in a pronated position. As for pronation, the PT and both heads of the PQ are active throughout the whole rotation, being most efficient around the neutral position of the forearm. The ECU and FCU contribute significantly less to pronation and supination torque. However, they do generate potential pronating torque while the forearm is positioned maximally in supination and, to a lesser extent, potential supination torque while the forearm is positioned maximally in pronation.

Adult↗
PubMed2003

Paraplegia-related alterations of bone density in forearm and hip in Greek patients after spinal cord injury.

PURPOSE: Paraplegia due to spinal cord injury is related with sublesional bone demineralization with an increased incidence of pathologic fractures in lower extremities. This study was carried out in order to evaluate bone density alterations in forearm and hip in Greek paraplegic patients after spinal cord injury and to correlate the findings with the level of injury, the neurological status, the time interval from injury and the performing of physiotherapy and therapeutic standing. METHOD: Fifty-seven paraplegic patients (33 men and 24 women, with injuries sustained from 6 months to 27 years) and 36 able-bodied age-matched controls (25 men, 16 women) participated in the study. Bone mineral density (BMD) was measured by dual X-ray absorptiometry (DXA) in the proximal and distal forearm, the femoral neck, the greater trochanter and Ward's triangle. RESULTS: The measurements revealed a significant reduction of BMD of femoral neck (p<0.001 in male, p<0.001 in female paraplegics), greater trochanter (p<0.001 and p=0.001, respectively) and Ward's triangle (p=0.001 and p=0.005, respectively). Proximal forearm depicted non-significantly decreased BMD values and distal forearm depicted a slight increase in BMD values. The degree of demineralization was independent of factors such as complete or incomplete spinal cord injury, level of the lesion, physiotherapy and performing of standing. In addition to that, BMD values in both hip and forearm showed no statistically significant correlation with time after injury. CONCLUSIONS: BMD measurements in Greek paraplegic patients reveal bone loss, which most dramatically occurs in the region of hip with a consequent increase of fracture risk. Forearm measurements depict a non-homogeneous response with limited proximal bone loss and slight distal increase of BMD, the latter being possibly attributed to daily activities.

Adult↗
PubMed2002

A study of forearm versus finger stick glucose monitoring.

New glucose monitoring systems are now being launched into the market that offer the patient the option to test from an alternate site (forearm) with less pain. What is not clearly understood by patients and Health Care Providers is whether glucose measurements taken from the forearm are the same as the measurements taken from the finger. The objective of this study was to determine if results from the forearm are the same as results from the finger in normal use by the diabetic patient over a day. In clinical studies conducted in four physician's offices, patients were asked to measure their glucose from their forearm and finger ten times a day for ten days. The patients for this evaluation used the TheraSense FreeStyle glucose monitoring system. A total of 190 patients (of which 30% were type 1 and 70% type 2 diabetics) participated in this study. Patients also concluded their participation in this study with a post study questionnaire. A total of 18,036 data points were collected and used for analysis. Data was separated into four groups: preprandial, 1-h postprandial, 2-h postprandial, and bedtime. In three of the four groups, the mean bias was less than 1 mg/dL or %, whereas the 1-h postprandial group showed a mean bias of -6.02 mg/dL or %. The differences in bias between the 1-h postprandial to the preprandial and the 1-h postprandial to the 2-h postprandial, were statistically significant with a p value of <0.0001. Comparison of bias at 2-h postprandial to the preprandial bias was not statistically significant with a p value of 0.8073, indicating that the 2-h postprandial had an overall mean bias, the same as the preprandial. The 1-h postprandial results indicate that patients who test during this period of time could expect to see significant differences between their forearm and finger measurements. Patients who test during this time period should only test using their finger since this would best represent their true glucose. Patients who would test during periods identified as preprandial and 2-h postprandial could expect to see small differences between their forearm and finger measurements. These differences are also not dependent on the method by which patients use to control their disease.

Adult↗
PubMed1992

Racial differences in maximal vasodilatory capacity of forearm resistance vessels in normotensive young adults.

This study was performed to determine whether alterations in vascular structure exist in a biracial population of young (age 22.3 +/- 0.6 yrs [mean + SE]) normotensive men. We examined maximal vasodilatory capacity in 21 blacks and 20 whites (average blood pressure = 122/75 and 118/72 mm Hg, respectively). Forearm blood flow was determined at rest and after 10 min of ischemic handgrip exercise using venous occlusion plethysmography. Forearm vascular resistance was computed from blood flow and mean arterial blood pressure determined by auscultation. Minimum forearm vascular resistance was 23% higher in blacks (2.60 +/- 0.60) than in whites (2.11 +/- 0.41) (P = .005), and was unrelated to parental history of hypertension. The regression equation for minimum forearm vascular resistance (Y) and casual blood pressure (X) for blacks was Y = -1.782 + 0.0487X (r = 0.522); for whites it was Y = -1.165 + 0.0367X (r = 0.418). When the data were covaried on resting mean arterial blood pressure, blacks still had a higher minimum forearm vascular resistance (P = .014). The results suggest a racial difference in the vascular structure of the forearm resistance vessels.

Adult↗
PubMed1984

Forearm arterial compliance: a new measure of arterial compliance?

This study has investigated the origin of the pulsatile expansion of the forearm recorded by the amplification of the pulsatile signal derived from a mercury in rubber plethysmograph. Venous occlusion to pressures of 40 mmHg had no effect on the amplitude of the volume pulse, suggesting that the volume pulse originates in vessels distended by pressures above this level. Nitroglycerin in small doses (0.15 mg sublingual) increased the amplitude of the volume pulse without changing forearm vascular resistance, consistent with an arterial origin of the forearm volume pulse. The instantaneous relationship between the volume pulse and arterial pressure (forearm compliance) showed that nitroglycerin increased the volume pulse in association with a reduction in pulse pressure. As the volume pulse probably originates in the arterial system, the increase in forearm compliance is a measure of the increase in arterial compliance induced by nitroglycerin. Both the volume pulse and forearm compliance may be useful indicators of the effect of physiological and pharmacological interventions on the distensile properties of arteries.

Adult↗