Search PubMed⌕ Search

Biomedical subjects

H Danielsen

Publications and source records attributed to H Danielsen.

At least 55 records · Page 3Linked to original sources
PubMed1986

Renal water excretion before and after remission of nephrotic syndrome: relationship between free water clearance and kidney function, arginine vasopressin, angiotensin II and aldosterone in plasma before and after oral water loading.

An oral water load of 20 ml/kg body wt. was given to eight patients with nephrotic syndrome before and after remission of the syndrome, and to 13 healthy control subjects. Urine volume (D), free water clearance (C water), plasma concentrations of arginine vasopressin (AVP), angiotensin II (ANG II) and aldosterone (Aldo), were determined before and three times during the first 4 h after loading. D and C water increased to a significantly lower level (P less than 0.01) after water loading in patients with nephrotic syndrome than in control subjects, but D and C water were normal after remission of the syndrome. The maximum increase in C water (delta C water max.) was 1.07 ml/min (median) before remission and 7.93 ml/min after, compared with 8.01 ml/min in the control group. Creatinine clearance (Ccr) increased significantly after remission (63 ml/min to 88 ml/min, P less than 0.01), and the fractional excretion of sodium was enhanced. AVP was higher in the nephrotic syndrome both before (2.9 pmol/l) and after remission (2.9 pmol/l) compared with the control group (1.8 pmol/l). ANG II and Aldo did not change after remission and remained at the same level as in the control group. The elevation in delta C water max. after remission was accompanied by an increase in Ccr in all patients and delta C water max. and Ccr were significantly correlated (rho = 0.600, n = 16, P less than 0.05). No relationship was found between the change in delta C water max. and ANG II and Aldo.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1986

Morphological and functional characteristics of isolated resistance vessels in advanced uraemia.

In order to obtain direct information on the properties of the resistance vasculature of patients with advanced uraemia, a technique was developed to dissect out small arteries (internal diameter about 165 microns) from biopsies of subcutaneous fat. Such arteries responded in a concentration-dependent manner to noradrenaline and angiotensin II, and the maximal force developed suggested that the vessels were fully viable. Although the biopsies were normally taken during operations under general anaesthesia, biopsies taken under local anaesthesia also appeared to be fully viable, suggesting that this technique may prove useful as a general method for studying the intrinsic vascular properties of humans. Biopsies were taken from 20 patients with uraemia, all of whom were treated with chronic intermittent dialysis, and 11 control subjects; up to three vessels were examined per biopsy. The uraemic state was not associated with changes in vascular morphology, or in vascular reactivity or sensitivity to noradrenaline, angiotensin II, potassium or calcium. However, for the uraemic patients and for the controls there was a positive correlation between mean blood pressure and the ratio of vessel media thickness to lumen diameter, as well as a negative correlation between mean blood pressure and vessel active media stress. The results suggest that uraemia treated with dialysis may not be associated with altered properties of the resistance vasculature. However, it appears that uraemic hypertension is associated with both morphological and functional abnormalities of the resistance vasculature.

Adipose Tissue↗
PubMed1986

Exaggerated natriuresis in adult polycystic kidney disease.

Angiotensin II (AII), aldosterone (Aldo) arginine vasopressin (AVP) in plasma, serum osmolality (Sosm), and renal sodium excretion (UNaV) were studied before and after infusion of hypertonic sodium chloride solution in 20 patients with adult polycystic kidney disease (PKD) with normal or moderately reduced creatinine clearance (Ccr) and in 10 healthy control subjects. UNaV increased after sodium loading in all, significantly more in the PKD patients. AII and Aldo were normal before sodium loading and suppressed after saline in PKD patients and controls. The increase in VNaV correlated with Aldo in patients but not in controls. AVP before loading was increased in hypertensive PKD patients with reduced Ccr, but not in normotensive patients with normal Ccr. After hypertonic saline, Sosm increased to the same degree both in PKD and control subjects, but AVP increased more in those with PKD. The exaggerated natriuresis of PKD is probably not explained by a change in the activity of the renin-angiotensin-aldosterone system. The enhanced response of AVP to osmotic stimuli in PKD may be a compensatory reaction to a reduced renal tubular effect of AVP.

Adult↗
PubMed1986

Abnormal vasopressin and aldosterone response to furosemide in essential hypertension.

Plasma concentrations of arginine vasopressin (AVP), angiotensin II (AII), aldosterone (Aldo), urinary output (V), osmolar clearance (Cosm), free water clearance (CH2O), fractional excretions of sodium (FENa) and potassium (FEK), urinary sodium excretion rate (U-Na) and serum potassium (S-K) were determined in 9 patients with essential hypertension (group I) and 13 normotensive healthy control subjects (group II) before and three times during the first 4 hours after an intravenous injection of 40 mg of furosemide. AVP, AII, Aldo, V, Cosm, FENa, FEK and U-Na increased in both groups. However, the elevation in AVP was significantly more pronounced and the rate of increase in Aldo was significantly slower in group I than in group II. There were no significant differences in AII, V, Cosm, CH2O, FENa, FEK and U-Na between the groups. S-K was significantly reduced only in group I. AVP and AII were not significantly correlated to each other or to blood pressure. It is suggested that the responsiveness of the renal tubules to AVP is reduced in essential hypertension and that the larger increase in AVP might be a compensatory phenomenon. The slower increase in Aldo in essential hypertension could be attributed to the reduction in S-K.

Adult↗
PubMed1986

Expansion of extracellular volume in early polycystic kidney disease.

Blood volume (BV), extracellular volume (ECV), blood pressure (BP), creatinine clearance (CCr), plasma levels of angiotensin II (AII), aldosterone (Aldo) and arginine vasopressin (AVP), and serum osmolality (Sosm) were determined in 18 patients with adult polycystic kidney disease, 8 normotensive (group I), 10 hypertensive (group II), and in 11 control subjects (group III). ECV but not BV was increased in group I compared with group III, whereas BV and ECV did not differ significantly between groups II and III. In group II, Aldo and AVP were increased and AII tended to be increased, while in group I the hormone levels did not differ significantly from those in group III. Sosm did not differ significantly between the groups. In the combined patient group, CCr correlated positively with BV and ECV and negatively with BP. In the patients, AII and AVP were positively correlated with BP but not with CCr. The results suggest that both the renin-angiotensin system and AVP might be involved in the BP elevation, whereas expansion of ECV can be found without an increase in BP.

Adult↗
PubMed1986

Experience with percutaneous transluminal renal angioplasty in renovascular hypertension.

Percutaneous transluminal renal angioplasty (PTRA) was attempted in 17 patients with a diastolic blood pressure greater than or equal to 95 mmHg in spite of treatment with two or three antihypertensive drugs in combination and unilateral or bilateral renal artery stenosis with a reduction of vessel diameter to less than 25%. PTRA resulted in a dilatation of the stenosis in 12 patients. After an observation period of at least 6 months 2 patients were cured, 7 improved and 3 unchanged. Renal vein renin ratio (RVRR) was determined in the last 9 of these patients but was unknown when PTRA was done. RVRR was higher than 1.5 in 5 patients of whom one was cured and 4 improved and less than 1.5 in 4 of whom one was improved and 3 unchanged. No persistent complications were observed after PTRA. It can be concluded that PTRA is an effective antihypertensive treatment in several patients with renovascular hypertension, and a RVRR greater than 1.5 suggests a favourable outcome with regard to blood pressure regulation.

Adult↗
PubMed1986

Angiotensin II, aldosterone and arginine vasopressin in plasma in congestive heart failure.

Angiotensin II (AII), aldosterone (Aldo) and arginine vasopressin (AVP) in plasma were determined during basal conditions in seventeen patients with congestive heart failure and in seventeen control subjects. The same parameters were measured before and 1, 2 and 3 h after an oral water load of 20 ml (kg body weight)-1 together with urine volume (V) and free water clearance (CH2O) in seven patients with congestive heart failure and in seven control subjects. AII, Aldo and AVP were significantly higher in heart failure than in control subjects (AII:81 and 12 pmol l(-1) (medians), P less than 0.01; Aldo: 411 and 103 pmol l(-1), P less than 0.01; AVP: 5.3 and 2.0 pmol l)-1), P less than 0.01). AVP was positively correlated to Aldo in both heart failure (p = 0.593, n = 17, P less than 0.02) and control subjects (p = 0.511, n = 17, P less than 0.05), but in neither of the groups to AII. V and CH2O were significantly lower in heart failure when compared to control subjects (maximum increase in CH2O 3.55 and 5.86 ml min-1, P less than 0.02), but did not correlate directly with either A II, Aldo or AVP. Creatinine clearance was reduced in heart failure. It is concluded that the activity of both the renin-angiotensin-aldosterone system and the osmoregulatory system is enhanced in congestive heart failure, presumably as a compensatory phenomenon in order to maintain arterial blood pressure. It is suggested that the decrease in free water clearance may be attributed to both an elevated level of vasopressin and a reduced glomerular filtration rate.

Aged↗
PubMed1986

Relationship of angiotensin II, aldosterone, arginine vasopressin, adrenaline and noradrenaline in plasma, blood and extracellular volumes to blood pressure in chronic glomerulonephritis.

Blood volume, extracellular volume, blood pressure and the plasma levels of angiotensin II, aldosterone, adrenaline, noradrenaline and arginine vasopressin were determined in sixteen normotensive (group 1) and thirteen hypertensive patients (group 2) with chronic glomerulonephritis and in eleven normotensive control subjects (group 3). Blood volume and extracellular volume did not differ between the groups and no significant differences were found in any of the hormones measured when comparing group 1 or group 2 with group 3. In the hypertensives but not in the normotensives or control subjects, a highly significant positive correlation was found between diastolic blood pressure and blood volume (rho = 0.75, P less than 0.01) and between diastolic blood pressure and extracellular volume (rho = 0.74, P less than 0.01). Blood volume and extracellular volume correlated (P less than 0.05) in each of the groups. In conclusion, although no expansion of either blood or extracellular volume was found in chronic glomerulonephritis, a positive volume-pressure relationship could be demonstrated in hypertensive patients suggesting a role of volume factors in the pathogenesis in early stage chronic glomerulonephritis. The study does not give support to a major role of either angiotensin II, arginine vasopressin or catecholamines in the maintenance of nonmalignant hypertension in early stage chronic glomerulonephritis.

Adolescent↗
PubMed1986

The interaction between cell-surface antigens and antibodies bound to monodisperse polymer particles in normal and malignant cells.

The interaction between polymer particles with an immune ligand on their surfaces and normal (hepatocytes) and malignant (Raji) cells with a corresponding membrane receptor was investigated by scanning and transmission electron microscopy. The influence of time, temperature, and anti-metabolites on this process was studied. The results indicate that when particles with an immunoligand are added to cells with a corresponding membrane receptor, three successive steps are initiated, the first two of which are not dependent on the temperature or the metabolic state of the cells. The first step in this process is the binding of particles to the cell surface through the immunoligand on the particle and the receptor on the cell surface. The initial binding formed by immunoligand and corresponding receptor is followed by a stronger interaction between cell and particle. This second step seems to be governed by a successive antibody-antigen interaction: the zipper mechanism. A third step in the particle-to-cell interaction is characterized by movements of the cellular surface, as revealed by membrane folds, pseudopods, and lamellae extending from the surface and enveloping large parts of the particle.

Antigen-Antibody Reactions↗
PubMed1986

Renovascular hypertension. Ability to renal vein ratio to predict the blood pressure level 18-24 months after surgery.

Fourteen patients with severe hypertension and renal artery stenosis were treated surgically. One patient died 4 days after surgery due to a cerebral thrombosis. The other 13 patients were followed for 18-24 months. Five were considered cured since the diastolic blood pressure (DBP) was less than or equal to 90 mm Hg without therapy. Five were improved since DBP was less than or equal to 100 mm Hg during treatment with only one or two antihypertensive agents. There were unchanged. Renal vein renin ratio (RVRR) was greater than or equal to 1.5 either before or after furosemide in all patients who were cured or improved and less than or equal to 1.5 in 2 of 3 who were unchanged. It can be concluded that surgical treatment cured or improved 77% of the patients, and that a RVRR greater than or equal to 1.5 is a good predictor of the blood pressure lowering effect of surgery.

Adult↗
PubMed1986

Effect of exercise on plasma concentrations of arginine vasopressin, angiotensin II and aldosterone in hypertensive and normotensive renal transplant recipients.

Plasma concentrations of angiotensin II (A II), aldosterone (Aldo) and arginine vasopressin (AVP), and serum osmolality (Sosm) were determined before and after gradually increasing exercise loads on a bicycle ergometer in 10 hypertensive (group I) and 10 normotensive renal transplant recipients (group II), and in 15 healthy control subjects (group III). Working capacity was reduced in groups I and II. The A II, Aldo, AVP, Sosm increased in all groups after exercise. The A II was higher in group I than II and the percentage changes were significantly lower in groups I and II than in group III. There were no significant differences in Aldo between the groups either before or after exercise. The AVP was the same in groups I and II, and AVP in these groups was higher than in group III. The Sosm and AVP were significantly correlated in all groups. Neither A II, Aldo nor AVP were significantly correlated to systolic blood pressure (BP). Alterations in AVP, but not in A II or Aldo, were correlated to the degree of exercise load. It can be concluded that the renin-angiotensin-aldosterone system and the osmoregulatory system are stimulated during exercise in renal transplant recipients. The A II is elevated in post-renal transplant hypertension, but the responsiveness is reduced in both hypertensive and normotensive recipients. The alterations in AVP are probably secondary to changes in Sosm, and the higher AVP levels in recipients could be due to a decreased responsiveness of the renal tubules to AVP. Our findings are in good agreement with the hypothesis that hypertension after renal transplantation is angiotensin II-dependent.

Adult↗
PubMed1986

Post-renal-transplant hypertension. Urine volume, free water clearance and plasma concentrations of arginine vasopressin, angiotensin II and aldosterone before and after oral water loading in hypertensive and normotensive renal transplant recipients.

Urine volume (V), free water clearance (CH2O) and plasma concentrations of arginine vasopressin (AVP), angiotensin II (A II) and aldosterone (Aldo) were determined before and three times during the first 5 h after an oral water load of 20 ml/kg body wt in 19 patients with post-renal-transplant hypertension (group I), in 13 normotensive renal transplant recipients (group II) and in 20 control subjects (group III). Both V and CH2O increased significantly in all groups, but considerably less in groups I and II than in group III. When CH2O was related to glomerular filtration rate no differences existed between patients and control subjects. Basal AVP was the same in groups I (3.3 pmol/l, median) and II (3.0 pmol/l), but significantly (p less than 0.01) higher than in group III (1.9 pmol/l). Basal A II was significantly (p less than 0.01) elevated in group I (18 pmol/l) when compared to both groups II (10 pmol/l) and III (11 pmol/l), and the level was independent of the presence of native kidneys. Basal Aldo was the same in all groups. During loading, AVP was reduced in all groups, A II was almost unchanged, and Aldo was increased in groups I and II and reduced in group III depending on alterations in serum potassium. Thus urinary diluting ability is reduced in renal transplant recipients due to a reduced glomerular filtration rate. The enhanced A II in hypertensive renal transplant recipients gives further evidence for the point of view that hypertension is angiotensin-dependent in most of these patients.

Adult↗
PubMed1986

Urinary excretion of albumin and beta-2-microglobulin in hypertensive and normotensive renal transplant recipients during urinary diluting and concentrating tests.

Urinary excretion of albumin and beta-2-microglobulin was measured in nine hypertensive and nine normotensive renal transplant recipients and 10 healthy control subjects before and after an oral water load of 20 ml (kg body weight)-1 (study 1) and in eight hypertensive and 11 normotensive renal transplant recipients and 11 healthy control subjects during 24-h water deprivation (study 2). In both studies 1 and 2 urinary albumin excretion was significantly higher (p less than 0.01) in the hypertensive renal transplant recipients that in the normotensive patients and the control subjects (levels before loading; hypertensives: 23.9 micrograms/min (median), range 7.5-58.7; normotensives: 3.4 micrograms/min, range 1.0-49.3; controls: 2.9 micrograms/min, range 1.3-10.3). Urinary albumin excretion was significantly positive correlated to both systolic, diastolic and mean blood pressure (for mean blood pressure: rho = 0.625, n = 18, p less than 0.01) in transplanted patients. Albumin excretion tended to increase after water loading and to decrease during water deprivation in all groups. Beta-2-microglobulin excretion was approximately the same in all groups in both studies 1 and 2 and was not correlated to blood pressure. During a follow-up period of at least 18 months, none of the renal transplant recipients developed signs of chronic graft failure. Increased urinary albumin excretion in hypertensive renal transplant recipients thus appears to be caused by increased glomerular permeability that may be due to glomerular damage induced by arterial hypertension corresponding to the findings in essential hypertension.

Adult↗
PubMed1986

Impaired renal water excretion in early hepatic cirrhosis. Lack of relationship between renal water excretion and plasma levels of arginine vasopressin, angiotensin II, and aldosterone after water loading.

An oral water load of 20 ml per kg body weight was given to 9 patients with hepatic cirrhosis and 11 healthy controls. Urinary output, free water clearance, and plasma concentrations of arginine vasopressin, angiotensin II and aldosterone were determined before and three times during the first 4 h after loading. In the cirrhotic patients urinary output was significantly lower after loading than in the control subjects, mainly because of a lower free water clearance, and, in contrast to the healthy controls, the cirrhotic patients did not have natriuresis after water loading. No differences were found between patients and controls in arginine vasopressin, angiotensin II, aldosterone, or creatinine clearance. It is concluded that patients with well-compensated cirrhosis of the liver have an impaired ability to excrete sodium and water. This phenomenon does not seem to be due to increased arginine vasopressin secretion, activation of the renin-angiotensin-aldosterone system, or a decreased glomerular filtration rate.

Adult↗
PubMed1986

Hypotension in end-stage renal disease: effect of postural change, exercise and angiotensin II infusion on blood pressure and plasma concentrations of angiotensin II, aldosterone and arginine vasopressin in hypotensive patients with chronic renal failure treated by dialysis.

In 16 dialysis patients, 8 hypotensive and 8 normotensive, and 8 control subjects, blood volumes were studied and angiotensin II (AII), aldosterone (Aldo) and arginine vasopressin (AVP) were measured in the supine position, after standing upright for 5 min and after a standard exercise test. In 8 hypotensive and 7 normotensive dialysis patients and in 7 control subjects, the pressor response to AII infusion was determined. Baseline values for AII, Aldo and AVP were the same in the different groups but with a much wider range in uremic patients. After standing for 5 min. both hypotensive and normotensive dialysis patients were able to maintain blood pressure without a significantly greater increase in heart rate than was seen in controls. Contrary to controls, however, all non-nephrectomized dialysis patients responded with an increase in AII and Aldo after standing for 5 min. In controls, exercise induced a clearcut increase in AII, Aldo and AVP, while no such changes were detectable in either hypotensive or normotensive dialysis patients. No significant differences in blood volumes were detectable between the groups. The pressor response to AII infusion was decreased in both normotensive and hypotensive dialysis patients compared with controls. It can be concluded that circulatory adjustment is abnormal in both hypotensive and normotensive dialysis patients as indicated by extremely high baseline levels of AII in some patients, abnormal response of the renin-angiotensin-aldosterone system and AVP to postural change and exercise and a decreased pressor response to AII infusion. However, neither these abnormalities nor changes in blood volumes can directly account for the chronic hypotension seen in some dialysis patients.

Adult↗
PubMed1985

Effect of verapamil on renal plasma flow, glomerular filtration rate and plasma angiotensin II, aldosterone and arginine vasopressin in essential hypertension.

Renal plasma flow, glomerular filtration rate plasma angiotensin II, aldosterone and arginine vasopressin, free water clearance, blood pressure and body weight in 11 patients with mild to moderate hypertension were determined at the end of consecutive 6 week periods of administration of placebo and verapamil up to 120 mg t.i.d. Verapamil induced a 10% reduction in diastolic blood pressure. Compared with placebo none of the other parameters measured changed after treatment with verapamil. There was no significant correlation between blood pressure and arginine vasopressin in plasma. It is concluded that verapamil reduced blood pressure by vasodilatation without activation of the counterbalancing mechanisms commonly seen after treatment with vasodilating drugs, i.e. tachycardia, activation of the renin-angiotensin-aldosterone system, water and salt retention, and without affecting renal haemodynamics. AVP does not seem to be involved in blood pressure regulation in mild to moderate essential hypertension.

Adult↗
PubMed1985

Abnormal vascular function and morphology in pre-eclampsia: a study of isolated resistance vessels.

In order to obtain direct information about vascular changes associated with pre-eclampsia, the morphological and functional characteristics of isolated omental resistance vessels from 11 women with pre-eclampsia, 10 normotensive pregnant women and eight normotensive non-pregnant women were determined. In vessels from the women with pre-eclampsia, the ratio of media thickness to lumen diameter was increased, compared with that in vessels from the other two groups. The vessels from the women with pre-eclampsia had an increased responsiveness to angiotensin II and a decreased rate of relaxation, but only when compared with the vessels from the normotensive pregnant women. However, no difference in responsiveness to noradrenaline was found between any of the groups. The angiotensin II responsiveness of the vessels from the women with pre-eclampsia and from the non-pregnant women were similar, suggesting that pre-eclampsia is associated with an absence of the change in vascular function which normally occurs during pregnancy. The study provides direct evidence for an involvement of vascular abnormalities in the pathogenesis of pre-eclampsia.

Adult↗