| 1. |
- Eriksson, Mats, et al.
(författare)
-
Mental stress impairs endothelial vasodilatory function by a beta-adrenergic mechanism
- 2007
-
Ingår i: Endothelium. - : Informa UK Limited. - 1062-3329 .- 1029-2373. ; 14:3, s. 151-156
-
Tidskriftsartikel (refereegranskat)abstract
- Mental stress has been shown to impair endothelium-dependent vasodilation (EDV) in the human forearm. The aim of this study was to investigate if this response could be blunted by local infusions of beta-blockade (propranolol), alpha-blockade (phentolamine), or neurogenic blockade. Thirty-one young healthy volunteers underwent forearm blood flow (FBF) measurements, using venous occlusion plethysmography, during local intra-arterial infusions of metacholine (MCh; inducing EDV) and sodium nitroprussid (SNP; inducing endothelial-independent vasodilation [EIDV]), respectively. These measurements were repeated during a 5-min mental arithmetic stress test without (n = 8) or with concomitant local infusion of propranolol (n = 7) or phentolamine (n = 8) in the forearm or during axillary plexus blockade (n = 8). An index of endothelial vasodilatory function (EFI) was calculated as the EDV to EIDV ratio. Mental stress impaired EDV significantly (p < .05), and as a result, EFI was significantly reduced (p = .02). This effect on EFI could be blocked by propranolol and neurogenic blockade but not by phentolamine (p < .05). Thus, impairment of endothelial vasodilatory function induced by mental stress could be blocked by beta-adrenergic, but not alpha-adrenergic, receptor blockade.
|
|
| 2. |
- Fugmann, Andreas, et al.
(författare)
-
Blood flow is an important determinant of forearm glucose uptake following a mixed meal
- 2003
-
Ingår i: Acta Diabetologica. - : Springer Science and Business Media LLC. - 0940-5429 .- 1432-5233. ; 40:3, s. 113-117
-
Tidskriftsartikel (refereegranskat)abstract
- Insulin-mediated vasodilation has been suggested to be of importance for glucose uptake during normoglycemic hyperinsulinemia. If this also is valid after an ordinary mixed meal remains to be evaluated. Forearm blood flow (FBF) and forearm glucose uptake change (evaluated by venous occlusion plethysmography) and glucose arteriovenous differences were evaluated over 120 minutes in 10 healthy volunteers following an ordinary mixed meal (700-900 kcal, 34% of energy from fat). Fasting arterial glucose level was 4.9+/-0.9 mmol/l, and the maximum glucose level was reached 30 minutes after the start of ingestion (6.6+/-0.8 mmol/l, p<0.0001). Plasma insulin levels were increased four-fold. FBF increased rapidly within 20 minutes after the start of ingestion and reached its maximum after 50 minutes (94% higher than baseline level, p<0.01). After 2 hours FBF was still substantially elevated (75% above baseline level, p<0.01). Forearm glucose uptake increased fivefold already after 20 minutes ( p<0.01). During the 2 hours, the increase in FBF contributed to 41% of the forearm glucose uptake ( p<0.05). The present study showed that the increase in FBF seen after an ordinary mixed meal is important for the change in forearm glucose uptake. These results support the view that modulation of limb blood flow is a determinant of glucose uptake.
|
|
| 3. |
- Fugmann, Andreas, et al.
(författare)
-
Central and peripheral haemodynamic effects of hyperglycaemia, hyperinsulinaemia, hyperlipidaemia or a mixed meal
- 2003
-
Ingår i: Clinical Science. - 0143-5221 .- 1470-8736. ; 105:6, s. 715-721
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to evaluate the haemodynamic changes during hyperinsulinaemia, hyperglycaemia or hypertriglyceridaemia in relation to those following a mixed meal. Ten subjects were subjected to hypertriglyceridaemia (3.9 mmol/l) for 2 h by an infusion of Intralipid and heparin. Nine subjects received a hyperglycaemic clamp (12.5 mmol/l) with octreotide and low-dose insulin infusion to maintain normoinsulinaemia (10 m-units/l). Ten subjects received saline for 2 h as a control and, thereafter, 2 h of normoglycaemic hyperinsulinaemic clamp (80 m-units/l). Finally, ten subjects were evaluated for 2 h following an ordinary mixed meal. Calf blood flow was measured by venous occlusion plethysmography and cardiac index by thoracic bioimpedance. Both the mixed meal and normoglycaemic hyperinsulinaemia lowered total peripheral resistance, and increased calf blood flow and cardiac index, whereas blood pressure decreased (P <0.05-0.001). Both hyperglycaemia and hypertriglyceridaemia increased calf blood flow, but blood pressure was unchanged. Total peripheral resistance was unchanged in hypertriglyceridaemia, whereas hyperglycaemia induced a significant increase. Normoglycaemic hyperinsulinaemia induced a haemodynamic pattern similar, but to a lesser extent, to the pattern seen following a mixed meal. Hyperinsulinaemia seems to be a major mediator of the haemodynamic response, but other factors are obviously also of great importance. Hypertriglyceridaemia and hyperglycaemia induced haemodynamic responses that are not similar to those seen following a mixed meal.
|
|
| 4. |
- Holmlund, A., et al.
(författare)
-
Soluble intercellular adhesion molecule-1 is related to endothelial vasodilatory function in healthy individuals
- 2002
-
Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 165:2, s. 271-276
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate the associations between markers of systemic and vascular inflammation, and indicators of vascular morphology and function. METHODS: In 59 apparently healthy individuals, we measured serum levels of highly sensitive C-reactive protein (hsCRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Endothelium-dependent (EDV) and -independent (EIDV) vasodilatation was evaluated in the forearm by venous occlusion plethysmography and local infusions of methacholine and sodium nitroprussid. Endothelial function index (EFI) was expressed as the EDV/EIDV ratio. The intima-media thickness (IMT) of the common carotid artery was investigated with ultrasound (far wall). RESULTS: EFI was inversely related only to ICAM-1 (r=-0.31, P<0.02) by univariate analysis. This association remained significant after adjustment for age, sex, blood pressure, smoking and serum cholesterol. EFI did not relate to hsCRP, VCAM-1 or E-selectin. Neither hsCRP, nor the adhesion molecules were significantly related to carotid artery IMT. CONCLUSION: ICAM-1 was related to endothelial vasodilatory function, but not to IMT, suggesting that endothelial inflammatory activation is related to an impaired vascular relaxation in apparently healthy individuals.
|
|
| 5. |
- Kurland, Lisa, 1960-, et al.
(författare)
-
Polymorphisms in the renin-angiotensin system and endothelium-dependent vasodilation in normotensive subjects
- 2001
-
Ingår i: Clinical Physiology. - : Wiley. - 0144-5979 .- 1365-2281. ; 21:3, s. 343-349
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Our aim was to test the hypothesis that genes encoding components in the renin-angiotensin system influence endothelial vasodilatory function. METHODS: In 59 apparently healthy, normotensive individuals, endothelium-dependent vasodilation (EDV) and endothelial-independent vasodilation (EIDV) was evaluated by infusing metacholine and sodium nitroprusside into the brachial artery. Forearm blood flow was measured by venous occlusion plethysmography. The ACE insertion (I)/deletion (D) polymorphism, the T174M and M235T angiotensinogen restriction fragments length polymorphisms, the angiotensin II receptor type 1 (AT1R) A1166C, and the aldosterone synthase gene (CYP11B2) C-344T polymorphisms were analysed. RESULTS: When analysing the ACE, the two angiotensinogen and the aldosterone synthase CYP11B2 genotypes independently, no significant association with endothelial vasodilatory function was found. However, a significant reduction in endothelium-dependent vasodilation was observed in the subjects (n=9) with the ACE D allele and the angiotensinogen T174M genotype (P<0.05). Subjects with the AT1R genotype AC showed a reduction in both EDV (P=0.05) and EIDV (P=0.04) when compared with those with the AA genotype. CONCLUSIONS: The subjects with the ACE D allele in combination with the angiotensinogen T174M genotype are associated with a reduced EDV. This together with the observation that the AC AT1R genotype is associated with a reduction in both EDV and EIDV, supports the hypothesis that endothelial vasodilatory function is influenced by genes in the renin-angiotensinogen system.
|
|
| 6. |
- Lind, Lars, et al.
(författare)
-
Endothelium-dependent vasodilatation in treated and untreated hypertensive subjects
- 1999
-
Ingår i: Blood Pressure. - : Informa UK Limited. - 0803-7051 .- 1651-1999. ; 8:3, s. 158-164
-
Tidskriftsartikel (refereegranskat)abstract
- It has repeatedly been shown that endothelium-dependent vasodilatation (EDV) is impaired in patients with untreated hypertension. The effect of antihypertensive treatment on EDV has, however, not been extensively investigated. In the present study, EDV and endothelium-independent vasodilatation (EIDV) were studied in 20 untreated and 41 treated hypertensive subjects and in 26 matched, normotensive controls by means of infusion of methacholine (MCh), 2 and 4 microg/min, evaluating EDV, and nitroprusside (SNP), 5 and 10 microg/min, evaluating EIDV, in the brachial artery. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. The vasodilatory action of MCh was impaired in untreated hypertensives compared with controls, with the response in the treated hypertensives in between the other two groups (p < 0.01 vs both of the other groups). EIDV, on the other hand, was enhanced in the treated hypertensives (p < 0.01), so that the MCh to SNP FBF ratio, an index of endothelial function, was attenuated in both treated and untreated hypertensives (0.97 +/- 0.24 and 0.96 +/- 0.15, respectively), compared with controls (1.27 +/- 0.29, p < 0.001). Both EDV and EIDV declined with increasing number of antihypertensive drugs used in the treated hypertensives (p < 0.05). In conclusion, the endothelial function index was found to be similarly depressed in both treated and untreated hypertensive subjects compared with normotensive controls. Antihypertensive therapy seems to improve the vasodilatory capacity in general rather than enhancing endothelial function.
|
|
| 7. |
- Lind, Lars, et al.
(författare)
-
Endothelium-dependent vasodilation and structural and functional changes in the cardiovascular system are dependent on age in healthy subjects
- 1999
-
Ingår i: Clinical Physiology. - : Wiley. - 0144-5979 .- 1365-2281. ; 19:5, s. 400-409
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate possible associations between endothelium-dependent vasodilatation (EDV) and cardiovascular structure and function. EDV could influence peripheral resistance and be affected by atherosclerosis and might thereby influence indices of cardiovascular structure and function. In a group of 31 apparently healthy men and 25 women (age range 20-69 years), EDV was evaluated by infusion of metacholine (4 micrograms min-1), and endothelium-independent vasodilatation (EIDV) was assessed by nitroprusside infusion (SNP, 10 micrograms min-1) in the brachial artery. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. Left ventricular (LV) geometry and function and the intima-media thickness in the carotid artery were assessed by ultrasonography. The stroke index to pulse pressure ratio was used to evaluate arterial compliance. Several indices of cardiovascular structure and function were found to be related to an index of endothelial function, the EDV to EIDV ratio. Furthermore, left ventricular mass (LVM), the atrio-ventricular plane displacement, E/A ratio, IVRT, the intima-media thickness of the carotid artery and arterial compliance were all significantly related to both EDV and EIDV in women. However, most indices of cardiovascular structure and function, as well as endothelial function, change with age and only the relation between LV diastolic function and endothelial function in men remained significant (P < 0.05) after including age in multiple regression analysis. Age was related to both cardiovascular structure and function, as well as to endothelial function. Multiple regression analysis showed that ageing generally affects cardiovascular characteristics and endothelial function in parallel in these healthy subjects.
|
|
| 8. |
- Lind, Lars, et al.
(författare)
-
Endothelium-dependent vasodilation is impaired in apparently healthy subjects with a family history of myocardial infarction
- 2002
-
Ingår i: Journal of Cardiovascular Risk. - : Oxford University Press (OUP). - 1350-6277 .- 1473-5652. ; 9:1, s. 53-57
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To investigate whether endothelial-dependent vasodilation is altered in healthy subjects with a family history of myocardial infarction. SETTING: Tertiary University Hospital SUBJECTS AND DESIGN: Fifty apparently healthy subjects selected from the general population were subjected to an evaluation of endothelial-dependent vasodilation (EDV) and endothelial-independent vasodilation (EIDV) by means of local infusion of methacholine (MCh, 2 and 4 microg/min) and sodium nitroprusside (SNP, 5 and 10 microg/min) with measurements of forearm blood flow with venous occlusion plethysmography. The occurrence of plaque and the intima-media thickness of the carotid arteries were determined by ultrasonography. RESULTS: Subjects reporting at least one parent suffering from myocardial infarction (n = 11) showed a significantly lower EDV than subjects without such a family history (21 +/- 3.7 vs. 26 +/- 6.7 ml/min/100 ml tissue at MCh 4 microg/min, P<0.05). EIDV was not significantly different between the groups (21 +/- 6.8 vs. 18 +/- 5.4 ml/min/100 ml tissue at SNP 10 microg/min). Age, sex distribution, body mass index, waist to hip ratio, blood pressure, lipids, fasting blood glucose, smoking habits and status of the carotid arteries were not significantly different between the groups. CONCLUSION: A family history of myocardial infarction was found to be associated with an impaired endothelial-dependent vasodilation in the forearm of apparently healthy subjects. The risk factor profile was not different from the control group, suggesting that genetic factors are responsible for the impaired endothelial-dependent vasodilation.
|
|
| 9. |
- Lind, Lars, et al.
(författare)
-
Methodological aspects of the evaluationof endotelium-dependent vasodilatation in the human forearm
- 1998
-
Ingår i: Clinical Physiology. - : Wiley. - 0144-5979 .- 1365-2281. ; 18:2, s. 81-87
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The present study, involving 56 healthy subjects from a health screening, was undertaken to address some methodological questions regarding the measurement of endothelial function using local intra-arterial infusions of metacholine (2 and 5 micrograms min-1) to evaluate endothelium-dependent vasodilatation, and sodium nitroprusside (SNP, 5 and 10 micrograms min-1) to evaluate endothelium-independent vasodilatation. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. The ratio of FBF during the highest dose of metacholine to FBF during the highest dose of SNP was used as an index of endothelial function. In 10 young volunteers the procedure was repeated after 2 h and again after 3 weeks in order to study short-term and long-term reproducibility of the method. Neither the vasodilatatory response to metacholine (r = 0.006) nor that to SNP (r = 0.08) was related to resting FBF. Neither the circumference nor the length of the arm was related to endothelial function (r = 0.01-0.11), as evaluated by the FBF on metacholine to nitroprusside ratio (mean 1.3 +/- 0.3 SD). The use of a wrist cuff to exclude hand circulation, or not, did not influence the evaluation of endothelial function significantly. Maximal FBF after 3 min of arterial occlusion of the forearm was significantly related to blood flow during both metacholine (r = 0.53, P < 0.01) and nitroprusside infusion (r = 0.36, P < 0.05), but not to the FBF on metacholine to nitroprusside ratio (r = 0.01). The short-term and long-term reproducibility of FBF during vasodilatation with metacholine and SNP was good (r = 0.89-0.97, P < 0.001), while the individual measurements for resting FBF were less reproducible when repeated after 3 weeks (r = 0.34). In conclusion, endothelial function was not related to resting FBF, nor to the arm circumference or length. No major difference was seen whether endothelial function was evaluated with or without exclusion of the hand circulation. Maximal FBF during reactive hyperaemia was not related to endothelial function.
|
|
| 10. |
- Lind, Lars, et al.
(författare)
-
The effect of smoking on endothelial vasodilatory function evaluated by local infusion of metacholine in the forearm is dependent on the duration of smoking
- 2003
-
Ingår i: Nicotine & tobacco research. - : Oxford University Press (OUP). - 1462-2203 .- 1469-994X. ; 5:1, s. 125-130
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to evaluate if endothelial vasodilatory function in the human forearm is impaired by regular cigarette smoking. The setting was a tertiary university hospital. Subjects were 56 apparently healthy subjects from a population screening (mean age 50) and 52 young healthy volunteers (mean age 25) who were investigated regarding endothelial-dependent (EDV) and endothelial-independent vasodilation (EIDV) by means of local infusion of metacholine (MCh; 2 and 4 mg/min) and sodium nitroprusside (SNP; 5 and 10 mg/min) in the forearm. Forearm blood flow (FBF) was measured by venous occlusion plethysmography. The MCh to SNP FBF ratio was denoted the endothelial function index. In the young subjects, no differences between smokers (n = 12) and non-smokers regarding EDV or EIDV were seen. In the population sample, however, the smokers (n = 8) showed an attenuated endothelial function index when compared with non-smokers (1.0 +/- 0.1 vs. 1.3 +/- 0.3, p = .02). The EDV showed a significant inverse relationship to the duration of smoking (r = -0.52, p < .05), independent of age, when the smokers in both groups were analyzed together. A similar, although not significant, relation was found between the endothelial function index and the duration of smoking (p = -.44). The present study showed that endothelial vasodilatory function was impaired in middle-aged, but not young, smokers, suggesting that the duration of smoking is of major importance for the deleterious effects of smoking on endothelial vasodilatory function.
|
|
