Effects of an antihypertensive medication on functional capacity under simulated flight-typical stress-conditions.

A model to investigate the functional capacity (psychomental performance) under stressful conditions was developed. Twenty eight patients with mild hypertension receiving Nitrendipine (20 mg) for 30 days were tested under hypoxic (16% oxygen) and/or orthostatic (-30 mmHg lower body negative pressure) conditions using a subset of the AGARD battery. The main effect was a decreasing performance of the grammatical reasoning task (GRT) under hypoxia or the combination of hypoxia and orthostasis. A simultaneous application of stressors while performing psychometric test batteries may be useful to reveal pharmaceutical influences on human performance and may help to recommend the use of drugs in occupational medicine.

Carnitine and experimental carbohydrate-induced hyperlipoproteinemia.

Carnitine, beta-hydroxy-gamma-trimethylaminobutyrate, plays an important role as a factor necessary for the transport of long-chain fatty acids into the mitochondria. In order to investigate the influence of L(--)-carnitine on hyperlipoproteinemias, the experimental model of the sucrose-induced hypertriglyceridemia of the rat was used. In these experiments L(--)-carnitine in the dose of 11 mg per day and 100 g body weight was able to antagonize the sucrose-induced hypertriglyceridemia and the increase of serum-free fatty acid level in female rats of the Wistar strain. Carnitine administration did not change the activities of lipogenic liver enzymes and the activity of post-heparin lipase. On the other hand, carnitine administration increased the rate of fatty acid oxidation in the liver. The main result of the study, i.e. the lipid-lowering effect of L-carnitine, suggests the use of this compound in the therapy of hyperlipoproteinemias.

[Effect of carnitine on experimental hypertriglyceridemia in rats]. / Vliianie karnitina na éksperimental'nuiu gipertriglitseridemiiu u krys.

Carnitine was shown to normalize the rat blood levels of triglycerides and fatty acids elevated by a 7-day administration of saccharose. It was also found that the serum content of endogenous carnitine is decreased in experimental hypothyroidism.

The response of some intravascular and intracellular lipid parameters of the rat after treatment with isatin.

The effect of isatin on serum lipid concentrations, the activity of lipoprotein lipase, the activity of lipogenic enzymes and the oxidation rate of fatty acids of female Wistar rats were investigated. A decrease of the triglyceride concentrations could be observed after one week of treatment of the group of sucrose-rich alimented animals, after two weeks this was also the case with the group fed with standard food. There were no changes in the cholesterol concentrations. Post-heparin lipolytic activity was not influenced. The liver enzymes malic enzyme, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase showed a remarkable increase in activity. The simultaneous rise of the oxidation rate of 14C-palmitate in the liver was measured. On the basis of the present findings the accelerated degradation rate could be responsible for the hypolipemic effect of the substance. The possible participation of the carnitine shuttle in the lipid-lowering action is discussed on the basis of changed concentrations of total carnitine, free carnitine and acylcarnitine in pooled serum samples after treatment with isatin.