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Biomedical subjects

I Eide

Publications and source records attributed to I Eide.

At least 109 records · Page 6Linked to original sources
PubMed1983

Increased beta-thromboglobulin in essential hypertension: interactions between arterial plasma adrenaline, platelet function and blood lipids.

Twenty-three 50-year-old men with untreated, essential hypertension had elevated plasma concentrations of the platelet release product beta-thromboglobulin (BTG) compared to 14 age-matched control men (p less than 0.01). BTG correlated with arterial plasma adrenaline concentrations in the hypertensive (r = 0.44, p less than 0.05), normotensive (r = 0.73, p less than 0.01) and combined group (r = 0.51, p less than 0.01). Significant correlations (p less than 0.05) between BTG and cholesterol (LDL + VLDL fraction) were observed both in the hypertensive and the normotensive group. In the hypertensive group arterial adrenaline correlated with cholesterol (LDL + VLDL) (p less than 0.05). These findings are consistent with increased platelet activity in middle-aged men with essential hypertension, and may indicate that plasma adrenaline influence platelet function. The risk factors for coronary artery disease (blood pressure, lipid status, stress as evidenced by catecholamine release and platelet function) were positively related. Measurement of arterial instead of venous adrenaline is essential for the demonstration of the associations presented.

Beta-Globulins↗
PubMed1983

Increased plasma free dopamine after treatment with atenolol and oxprenolol in essential hypertension.

In 19 men aged 50 with essential hypertension, 18 weeks' treatment with atenolol (n = 9) or oxprenolol (n = 10) increased supine plasma free dopamine concentrations by 78% (p less than 0.05) and 121% (p less than 0.001) respectively. Increments in plasma dopamine were observed in all patients except for one treated with atenolol. Supine peripheral venous adrenaline and noradrenaline concentrations were not influenced by beta-blockade. The mechanism and significance of the present elevation of plasma free dopamine by beta-blockade are unknown. However, increased plasma free dopamine may be involved in the hypotensive effect of chronic beta-adrenergic blockade, both beta-1 selective and non-selective, and may lend further support to decreased dopaminergic activity in essential hypertension.

Atenolol↗
PubMed1983

Increased peripheral catecholamine release in patients with long-standing, untreated essential hypertension.

Both arterial and venous plasma adrenaline and noradrenaline concentrations were elevated in 20 middle-aged men with long-standing, untreated essential hypertension compared to 19 normotensive control men (p less than 0.01). The mean a-v (arterial-venous) difference of adrenaline and v-a difference of noradrenaline were increased in the hypertensive (p less than 0.05) consistent with raised adrenal adrenaline release and release of noradrenaline from the peripheral vascular beds of the forearm.

Blood Pressure↗
PubMed1983

Relationship between catalase activity and uptake of elemental mercury by rat brain.

Uptake of mercury by brain after intravenous injection of elemental mercury was investigated in the rat. Catalase activity was inhibited by aminotriazole either by intraperitoneal injections affecting catalase in most tissues of the animal or by intraventricular injections affecting catalase in the brain selectively. Uptake of elemental mercury by rat brain was not influenced by intraperitoneal administration of aminotriazole resulting in 50% inhibition of brain catalase. However, when the inhibitor was injected intraventricularly in concentrations to give a 50% inhibition of brain catalase, it was shown that the mercury uptake by the brain was significantly decreased. In the latter case when only brain catalase was inhibited and the supply of elemental mercury to brain was maintained, mercury uptake by brain was proportional to the activity of catalase in brain tissue and to the injected amount of elemental mercury. Contrary to the intraventricular injection of aminotriazole, in animals receiving aminotriazole intraperitoneally prior to elemental mercury injection, we suggest that the lower activity of brain catalase is compensated by an increased supply of elemental mercury caused by the generally lower oxidation rate in the animal. This view is supported by the finding that mercury uptake by liver increased due to aminotriazole intraperitoneally although activity of catalase was depressed.

Amitrole↗
PubMed1983

Dopamine release from the porcine myocardium.

Dopamine is a catecholamine with profound influence on cardiac function and known to be present in adrenergic nerve terminals as a precursor of noradrenaline. However, no previous study has examined whether dopamine is produced by myocardial tissue. During stable hemodynamic conditions in 13 young, thoracotomized pigs with the heart in situ, we found a net release of dopamine into the coronary sinus amounting to 1.39 +/- 0.36 ng/min X 100 g of left ventricular muscle mass (p less than 0.01). Dopamine was released from the myocardium whether the v-a difference for noradrenaline was positive or negative. This observation indicates a release of dopamine from the heart independent of sympathetic noradrenergic activity. Regulation of myocardial dopamine release remains unknown.

Animals↗
PubMed1983

Conditions for augmentation of renin release by theophylline.

Isoproterenol, dopamine, glucagon and dibutyryl cyclic AMP (DB-cAMP) increase renin release at low but not at control blood pressure. These findings suggest that autoregulated afferent arteriolar dilation is a prerequisite of renin release mediated by intracellular generation of cyclic AMP. To examine this hypothesis further the effects on renin release of theophylline, which would maintain high intracellular concentration of cAMP by inhibiting phosphodiesterase, were studied in anesthetized dogs. After inhibiting beta-adrenergic stimulation with propranolol, theophylline increased renin release significantly from 0.7 +/- 0.2 to 1.8 +/- 0.7 micrograms/min at control blood pressure and from 23 +/- 4 to 41 +/- 5 micrograms/min at a renal perfusion pressure of about 50 mmHg. The greater effect at low blood pressure occurred despite adjustment of the infusion rate of theophylline to keep arterial plasma concentration of theophylline unaltered. Isoproterenol infusion at low blood pressure raised renin release from 41 +/- 11 to 76 +/- 19 micrograms/min before and 54 +/- 13 to 108 +/- 31 micrograms/min during continuous infusion of theophylline. The renin release response to infusion of theophylline at low blood pressure was not enhanced by DB-cAMP infusion. We conclude that arteriolar dilation provides a condition for stimulation of renin release during the theophylline infusion. Theophylline infusion may augment the effect of isoproterenol on renin release by delaying the intracellular degradation of cAMP.

Animals↗
PubMed1983

Effects of posture on serum cholesterol fractions, cholesterol ratio and triglycerides.

In 41 healthy men aged 50 fasting serum HDL cholesterol, total cholesterol, LDL + VLDL cholesterol and triglycerides increased by 8.3, 9.6, 9.9 and 11.3%, respectively (all P less than 0.001), after 30 min standing compared to 30 min in the supine position. These findings can be fully explained by decrease in plasma volume on changing from lying to the erect position. However, the cholesterol ratio (HDL cholesterol X 100/LDL + VLDL cholesterol) was not influenced by posture and should be evaluated instead of cholesterol fractions if the conditions for blood sampling were not controlled.

Cholesterol↗
PubMed1983

Decreased peripheral dopaminergic activity in essential hypertension?

In 42 men aged 50 +/- 1 years with untreated, sustained essential hypertension and in 34 age-matched normotensive men plasma free dopamine concentrations in venous blood in the standing position were more than 60% higher than supine values indicating dopamine involvement in the orthostatic response. In both the hypertensive and normotensive group supine arterial plasma dopamine concentrations were significantly higher than venous supine (P less than 0.004) indicating release of this catecholamine from central organs such as brain, kidneys or adrenals. In the hypertensive group both venous supine, arterial and venous standing plasma dopamine concentrations and the urinary excretion of this catecholamine were lower than in the normotensive group. Between the groups, statistical significance was achieved for venous standing dopamine concentrations (P less than 0.04) and when venous supine, arterial and standing plasma concentrations were added together for each individual (P less than 0.03). The findings may indicate decreased peripheral dopaminergic activity in patients with essential hypertension.

Dopamine↗
PubMed1983

Blood lipids and antihypertensive drugs. The Oslo study.

The treatment of hypertension has failed to achieve a reduction of the incidence of coronary heart disease. Recently, attention has been drawn to the effects of antihypertensive drugs on the metabolism of lipoproteins. Of the beta-blockers only pindolol was lipid neutral while propranolol, atenolol and oxprenolol lowered cholesterol and increased serum triglycerides. Hydrochlorothiazide did not influence blood lipids. Prazosin lowered serum LDL + VLDL cholesterol and total triglycerides. The combination of pindolol + prazosin lowered LDL + VLDL cholesterol and increased triglycerides. Propranolol + prazosin lowered HDL cholesterol, methyldopa + hydrochlorothiazide and hydrochlorothiazide + amiloride had no effect on blood lipids.

Antihypertensive Agents↗
PubMed1983

Influence of body weight on plasma catecholamine patterns in middle-aged, normotensive men.

To study the influence of body weight on plasma catecholamine patterns, 34 healthy, normotensive men aged 51 +/- 1 years were stratified into lean (n = 22) and overweight (n = 12) subjects according to Thomas' body mass index. No significant differences on supine arterial and venous catecholamines or standing venous adrenaline and dopamine appeared. However, the lean men had an increased orthostatic venous noradrenaline response (477 +/- 38 ng/l) compared to the overweight (319 +/- 46 ng/l, P less than 0.02). The present findings may indicate an inverse relationship between the sympathetic noradrenergic responsiveness and body weight in healthy, normotensive men while no differences were found in basal catecholamine levels.

Blood Pressure↗
PubMed1983

Increased arterial catecholamine concentrations in 50-year-old men with essential hypertension.

In a recent study of 50-year-old men with long-standing, untreated essential hypertension we found increased arterial and venous plasma concentrations and arterial-venous differences of adrenaline (a-v) and noradrenaline (v-a) as compared to a matching normotensive control group. The aim of the present study was to investigate whether men of this age with hypertension of shorter duration and less severity than in the first study might also have increased plasma catecholamines. Twenty-three hypertensive and 17 age-matched normotensive control men were studied. The hypertensive ones had increased supine heart rate (P less than 0.05), arterial noradrenaline (P less than 0.01) and adrenaline (P less than 0.02) whereas venous catecholamines did not differ between the two groups. The a-v differences (means +/- SE) of adrenaline (78 +/- 14 vs 42 +/- 6 ng/l, P less than 0.05) were increased in the hypertensive compared to the normotensive group. In the hypertensive, the arterial plasma concentrations of the two catecholamines correlated positively (r = 0.71, P less than 0.001) as did the a-v differences (r = 0.54, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure Determination↗
PubMed1982

Anion and osmolal gaps in the diagnosis of methanol and ethylene glycol poisoning.

The diagnostic value of determination of the anion and osmolal gaps was studied in 6 patients poisoned with methanol and in 5 poisoned with ethylene glycol. Increased osmolal gap was present on admission in all patients, whereas increased anion gap was present in all except one. In the methanol-poisoned patients the mean blood values were: pH 7.27, anion gap 24 mmol/l, osmolal gap 81 mosmol/kg H2O, methanol 67 mmol/l, ethanol 11 mmol/l and in the ethylene glycol-poisoned patients: pH 6.93, anion gap 38 mmol/l, osmolal gap 35 mosmol/kg H2O and ethylene glycol 24 mmol/l. In the absence of alcoholic acidosis or diabetic coma the finding of a simultaneous increase in both the anion and osmolal gaps indicates methanol or ethylene glycol poisoning. Thus determinations of the anion and osmolal gaps are mandatory whenever facing metabolic acidosis of unknown etiology.

Acid-Base Equilibrium↗
PubMed1982

Antihypertensive drugs and blood lipids: the Oslo study.

1 The report presents the effects on blood lipids and uric acid of six different antihypertensive drugs, used alone and of five different combinations of two antihypertensive drugs. 2 Prazosin significantly lowered serum LDL + VLDL cholesterol and total triglycerides. Atenolol lowered LDL + VLDL cholesterol to a smaller but significant extent. Both pindolol and hydrochlorothiazide (HCTH) were without effect, while oxprenolol significantly increased total triglycerides. Propranolol significantly lowered HDL cholesterol and increased total triglycerides and uric acid. 3 The combination prazosin and pindolol had a favourable effect on the lipid profile, while the combination propranolol and HCTH lowered HDL cholesterol but increased total triglycerides. Propranolol and prazosin lowered HDL cholesterol, while methyldopa and HCTH, and HCTH and amiloride were without effect on blood lipids. 4 It is suggested that the metabolic effects of antihypertensive drugs could be of special importance in long-term treatment of mild hypertension.

Adult↗
PubMed1982

Uptake of elemental mercury and activity of catalase in rat, hamster, guinea-pig, normal and acatalasemic mice.

Uptake of elemental mercury after inhalation (3.5 mg/m3) and the activity of catalase in brain, liver, kidney and blood were investigated in rat, hamster, guinea-pig, and normal and acatalasemic mice. The uptake of mercury in the species investigated varied considerably, being highest in the two strains of mice, followed by rat and hamster, and lowest in the guinea-pig. The uptake seemed to be more dependent on pulmonary ventilation than on the activity of catalase. The two strains of mice were exposed to a wide range of mercury concentrations in air (0.002-3.5 mg/m3). The content of mercury in brain, liver and kidney was linearly dependent on the mercury concentration in the air, whereas in blood this relationship was exponential. At the lower concentrations of mercury in the inhaled air, the mercury level in blood was significantly lower, and in kidney higher in the acatalasemic mice compared to the normal ones. In acatalasemic mice the mercury content in liver was higher at all concentrations investigated, whereas in brain no difference between the two strains was found.

Acatalasia↗
PubMed1982

Conditions for enhancement of renin release by isoproterenol, dopamine, and glucagon.

Isoproterenol infusion increases renin release at low but not at control blood pressure. To examine whether this effect is dependent on arteriolar dilation and is specific for agonists of beta-adrenoceptors, responses to intrarenal infusion of isoproterenol (0.2 micrograms.kg body wt-1.min-1), glucagon (0.1 micrograms.kg body wt-1.min-1), and dopamine (1 micrograms.kg body wt-1.min-1) were compared at control and low or high ureteral pressure, which also dilates the renal arterioles. During renal arterial constriction, renin release was equal at two perfusion pressures below the range of autoregulation and was 76 +/- 24 micrograms/min higher during isoproterenol than during propranolol administration. Intravenous infusion of isoproterenol gave qualitatively similar results. Intrarenal infusion of glucagon and dopamine increased renin release by 13 +/- 3 and 22 +/- 12 micrograms/min, respectively; enhancement of renin release was also present after propranolol administration. During ureteral occlusion, intrarenal infusion of isoproterenol, dopamine, and glucagon increased renin release from 30-40 micrograms/min by 78 +/- 11, 13 +/- 3, and 31 +/- 10 micrograms/min, respectively. At control blood and ureteral pressure, the effects on renin release of infusing isoproterenol, dopamine, or glucagon were small or absent. Thus, isoproterenol, dopamine, amd glucagon enhance renin release when the arterioles are dilated by renal arterial constriction or ureteral occlusion.

Animals↗