No abstract

To determine the effect of the taurine containing drink "Red Bull" on cardiac parameters thirteen endurance trained subjects performed an exhaustive bout of endurance exercise at three different times. Prior to the exercise the original "Red Bull" drink, a similar drink without taurine, containing caffeine, and a "placebo" drink without caffeine and without taurine were ingested by the subjects in a double-blind cross-over design. Echocardiographic examinations were performed before the drinks, 40 minutes after the drinks prior to the exercise and in the regeneration period after exercise. Stroke volume was significantly influenced only in the "Red Bull group" (80,4+/-21,4 ml before drink vs. 97,5+/-26,2 ml in the regeneration period), mainly due to a reduced endsystolic diameter and volume. Furthermore in this group the peak late diastolic inflow (V(A)) in the regeneration period was significantly higher compared with the pre-exercise levels. This observation was also made in the caffeine group but without any consequences on ventricular function. The results of the present study show an influence of the original caffeine and taurine containing drink (Red Bull) on parameters of the cardiac contractility.

Thirty-three rats were trained to avoid shock in a novel avoidance apparatus that required S to climb or jump onto a ledge in order to avoid. When Ss had achieved a learning criterion, they were assigned to one of three groups, each of which received a different experimental treatment prior to extinction training. Group I, the normal-control group, received no interruption between acquisition and extinction. Group II, the time-control group, spent a 5-min. interval on the safety ledge between the last acquisition trial and the first extinction trial. Group III, the experimental response-prevention group, spent a 5-min. interval on the grid floor of the apparatus between acquisition and extinction. For Group III Ss, the ledge was removed from the apparatus to prevent the occurrence of avoidance responses during the response-prevention interval. The results showed that Group III (response-prevention) Ss extinguished significantly sooner, confirming previous findings.

An apparatus and procedure for the avoidance training of rats is described. 22 rats were trained in the apparatus, and the rapidity of learning was contrasted with that of previously-used automated apparatuses. The new technique prevented many major problems associated with traditional avoidance procedures, both automated and manual.

The aim of this study was to investigate whether moderate or exhaustive endurance exercise influences cytokine levels in whole-blood culture supernatants after stimulation. Therefore, eight healthy subjects were first exposed to moderate exercise on a cycle ergometer for 30 min at 70% of their 4-mmol/l lactic acid (anaerobic) threshold, and 1 week later to exhaustion (for 90 min) at their anaerobic threshold. Blood samples were taken before, 30 min after and 24 h after each exercise bout. The following lymphocyte subpopulations were determined: CD14-positive(+)/CD45+, CD4+, CD8+, and CD16+. Cytokine levels in the supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Production of interleukin (IL)-1beta, IL-6 and tumour necrosis factor (TNF)-alpha were induced with lipopolysaccharides (LPS), and that of IL-2 and interferon (IFN)-gamma with staphylococcal enterotoxin B (SEB) and phytohaemagglutinin (PHA). Cortisol levels were also determined by ELISA. The lymphocyte subset distribution was observed to be unchanged after moderate exercise. Thirty minutes after exhaustive exercise, the CD16+ count was found to be significantly lower, whereas 24 h later the CD4+ count was significantly higher than pre-exercise counts. Moderate exercise influenced the IFN-gamma production (PHA-stimulated), which increased significantly from 974 (391) pg/ml before exercise to 1450 (498) pg/ml 24 h later. Thirty minutes after exhaustive exercise the IFN-gamma level in the supernatants (SEB-stimulated) was significantly decreased (from 14470 (11840) pg/ml before exercise to 6000 (4950) pg/ml after exercise). The IL-1beta and TNF-alpha production per monocyte was also significantly reduced.