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Biomedical subjects

T L Svendsen

Publications and source records attributed to T L Svendsen.

90 records · Page 5Linked to original sources
PubMed1978

Effect of labetalol on plasma noradrenaline and adrenaline in hypertensive man.

Injection i.v. of labetalol, a new adrenergic alpha- and beta-blocking agent, decreased arterial blood pressure in 9 hypertensive subjects resting in the supine position, when standing and during supine exercise. Heart rate after labetalol was unchanged in the resting supine position, and it fell in the latter two conditions. Plasma noradrenaline concentration was higher after labetalol in all three experiments as compared to a control study. Plasma adrenaline after labetalol was increased only in the standing position, when the highest plasma noradrenaline concentrations were observed. Blood glucose concentration tended to increase after labetalol, but the difference was not statistically significant. The changes in plasma noradrenaline and blood glucose after labetalol mimic findings observed after alpha-adrenergic receptor blockade. The beta-adrenergic receptor blocking property of labetalol is responsible for the reduced heart rate and it is likely to contribute to the higher plasma noradrenaline concentration observed when standing and during supine exercise.

Adult↗
PubMed1978

Effect of adrenergic beta receptor blockade on ethanol elimination and on ethanol-induced changes in carbohydrate and lipid metabolism in man.

The effect of adrenergic beta receptor blockade on the elimination rate of ethanol was studied in seven healthy young men. The studies were performed before and after 14 days of propranolol 240 mg/day: the ethanol was given per-orally--0.8 mg/kg b.w. The blood concentration of ethanol, glucose, lactate and glycerol, and the plasma concentration of free fatty acids and triglycerides were followed in samples from the superior vena cava taken every 20 min for four hours. The splanchnic hepatic blood flow was estimated with a single i.v. injection of indocyanine green. The absorption rate, absorption fraction and elimination rate of ethanol were not changed by propranolol. The splanchnic hepatic blood flow was significantly reduced (mean 19 per cent) during beta receptor blockade. The ethanol-induced change in the concentration of glucose, lactate and free fatty acids was affected by propranolol, the time-concentration curves for glucose and lactate being significantly elevated and that for free fatty acids being significantly reduced. The time-concentration curves for glycerol and triglycerides did not differ in the two studies.

Adolescent↗
PubMed1978

The distensibility of the resistance vessels of skeletal muscle in hypertensive patients.

The distensibility of the resistance vessels of skeletal muscle was evaluated in 23 patients with essential arterial hypertension (WSHO grade I--II), and in 14 normotensive control sugjects. Five of the hypertensive patients were well treated for over 2 years and 18 were untreated. The 133Xenon wash-out rate from the anterior tibial muscle during reactive hyperemia was recorded before and during an increase of the vascular transmural pressure, brought about by application of a subatmospheric pressure to the leg. At ambient pressure the 133Xenon wash-out rate did not differ between the normotensive and hypertensive subjects, reflecting equal muscle blood flows. However, when the transmural pressure was augmented the 133Xenon wash-out rate in the normotensive subjects increased about twice as much as in the hypertensive patients. This suggests a decreased distensibility of the resistance vessels in hypertensive patients as compared to normotensive subjects, and supports the concept that structural changes of these vessels take place in arterial hypertension. Since the vascular distensibility was equally reduced in the untreated and well treated hypertensive patients it is indicated that the structural changes in the resistance vessels of the leg muscles do not readily decline during antihypertensive treatment.

Adult↗
PubMed1976

The influence of disulfiram on the half life and metabolic clearance rate of diphenylhydantoin and tolbtamide in man.

Diphenylhydantoin (DPH) and tolbutamide serum levels were studied in ten volunteers before and after 4 days of disulfiram treatment. The mean DPH half life increased significantly from 11.0 +/- a.2 h to 19.0 +/- 3.3 h, and the mean DPH metabolic clearance rate decreased significantly from 51.2 +/- 17.2 ml/min to 33.9 +/- 12.0 ml/min during medication. No significant changes in the half life or metabolic clearance rate of tolbutamide was observed.

Adult↗
PubMed1975

Electrolyte disturbances in beer drinkers. A specific "hypo-osmolality syndrome".

A syndrome is described which affects subjects whose consumption of beer is considerable but who take no or little ordinary food. The symptoms include fatigue, dizziness, and muscular weakness; the biochemical changes are hyponatraemia and hypokalaemia. The disorder is rapidly resolved by stay in hospital. Beer is poor in Na (1-2 meq. per litre). Consequently these patients' intake of Na was low, and the production of urea was very low.

Aged↗
PubMedDate not supplied

A comparison of the hemodynamic effects of prenalterol and isoprenaline in patients with complete heart block.

Prenalterol is a new beta-adrenergic agonist which stimulates mainly beta 1-receptors, in contrast to isoprenaline which stimulates both beta 1- and beta 2-receptors. We studied the hemodynamic effects of prenalterol and isoprenaline in seven patients with complete heart block and idioventricular escape rhythm due to ischemic heart disease. Isoprenaline was given as a continuous infusion at two increasing doses (1.7 micrograms/min and 3.4 micrograms/min each given for 30 min). After the second dose of isoprenaline the cardiac index was increased from 2.27 +/- 0.06 to 3.61 +/- 0.60 1/min/m2, heart rate was increased from 34.1 +/- 1.2 to 50.4 +/- 3.1 beats/min and mean blood pressure was decreased by 12.4 mm Hg. Mean pulmonary artery pressure was increased by 2 mm Hg. Prenalterol was given as two i.v. bolus injections of 3.5 mg and 7.0 mg at 15-min intervals. The first dose of prenalterol increased the cardiac index from 2.22 +/- 0.10 to 2.42 +/- 0.12 and heart rate from 37.0 +/- 1.8 to 40.1 +/- 1.7. Mean blood pressure and mean pulmonary artery pressure were unchanged. The second dose of prenalterol did not change the hemodynamic variables significantly compared to the changes after the first dose. We conclude that isoprenaline is preferable to prenalterol for treatment of complete heart block.

Adrenergic beta-Agonists↗
PubMedDate not supplied

Do we undertreat hypertensive smokers? A comparison between smoking and non-smoking hypertensives.

The acute effect of smoking is a rise in blood pressure and heart rate. Nevertheless, in several epidemiologic studies, smokers tend to have a slightly lower office blood pressure than non-smokers. We studied the 24 h ambulatory blood pressure consecutively in hypertensive smokers (> or = 10 cigarettes per day, n = 26) and hypertensive non-smokers (n = 26) to test the hypothesis that smoking is associated with a rise in ambulatory blood pressure. There was no difference between smokers and non-smokers in office blood pressure (153.8 +/- 22.2/98.5 +/- 10.6 vs 149.0 +/- 16.1/96.9 +/- 11.6 mmHg). However, we found a statistically significant higher daytime systolic and diastolic blood pressure in smokers (153.7 +/- 16.2/96.1 +/- 9.5 vs 145.0 +/- 12.1/90.1 +/- 10.0 mmHg) than in non-smokers. Differences were also found for office-daytime differences and when studying patients on pharmacological antihypertensive treatment separately. Daytime heart rate was also significantly higher in smokers (86.6 +/- 9.4 vs 76.0 +/- 10.9). We conclude that smokers tend to be undertreated in that they have a higher daytime blood pressure than do non-smokers, a difference that is not recognized by measuring office blood pressure alone. We therefore recommend 24h ambulatory blood pressure measurement in smokers with essential hypertension.

Adult↗