Lack of serum cholesterol-lowering effect of skimmed milk and butter milk under controlled conditions.

The effects of skimmed milk and butter milk on the plasma concentration of cholesterol, triglyceride and high density lipoprotein cholesterol were studied in voluntary male prisoners under carefully controlled conditions. No significant differences were observed in the serum lipid or lipoprotein levels between the groups ingesting the control diet and the diets containing 2.71 of skimmed milk or 2.01 of butter milk per day for 3 weeks.

Comparison of the diuretic effects of single dose frusemide/triamterene and hydrochlorothiazide/amiloride in healthy adults.

The diuretic and potassium- and magnesium-conserving action of a single dose of frusemide/triamterene, F + TRI (40 mg/50 mg), and hydrochlorothiazide/amiloride, HCT + AMI (50 mg/5 mg), fixed combination preparations were compared in ten healthy adults in a randomised double-blind placebo-controlled study. Urinary volume during 24 hours was significantly higher after HCT + AMI ingestion than after F + TRI. The urine and sodium excretions caused by HCT + AMI lasted markedly longer and were smoother than the short and somewhat unpleasant effects of F + TRI. HCT + AMI also spared potassium and magnesium relatively more effectively than F + TRI.

Stability of human plasma catecholamines.

Human plasma catecholamines, measured by a radioenzymatic method, in general exhibit a marked stability when stored in plasma or whole blood. The storage of blood samples for several hours at room temperature, without prior separation of plasma, did not result in any losses of plasma noradrenaline or adrenaline. Moreover, the addition of thiol compounds (such as reduced glutathione, 2-mercaptoethanol or dithiothreitol) or other antioxidants (sodium metabisulphite) was not required during the storage. Although catecholamines were stable when kept in whole blood at room temperature, they were swiftly degraded when stored in buffer solutions in the absence of thiols. In one subject adrenaline and noradrenaline were repeatedly found to increase significantly in concentration in the course of the first 30 min of storage. The reason for this anomalous increase is unknown. The observed stability of catecholamines in blood is in striking contrast to some earlier reports. It appears to be premature to categorically neglect any precautions as regards the centrifugation, sampling and processing blood samples used for plasma catecholamine determinations; however, when a given routine method is employed one may check the apparent stability of noradrenaline and adrenaline. In some cases this may justify omitting some of the tedious and expensive arrangements suggested in the literature for sample processing.

Plasma catecholamines in Finnish sauna.

Plasma catecholamines were measured by a modified single-isotope radioenzymic assay in five healthy medical students during and after a Finnish sauna bath with or without previous beta-blockade. The plasma noradrenaline rose more than twofold after 10 min in the hot room (100 degrees C) while the plasma adrenaline content exhibited smaller increases. The plasma noradrenaline concentration remained elevated or further increased after 5 min in a cool swimming pool (22 degrees C) whereas the exposure to cool water restored the plasma adrenaline concentration to resting values. Plasma noradrenaline, but not adrenaline, was still markedly elevated after a rest period of 15 min after the cool pool. Oxprenolol (40 mg) given 30 min before the sauna did not alter the plasma catecholamine pattern although it effectively lowered the heart rate before, during, and after the exposure to the heat stress.