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Biomedical subjects

J E Hueting

Publications and source records attributed to J E Hueting.

7 recordsLinked to original sources
PubMed1995

No influence of ACTH on maximal performance.

Although it is generally accepted in the sporting world that adrenocorticotropic hormones (ACTH) and corticosteroids enhance maximal performance, this claim has never been scientifically corroborated. In a counterbalanced, double-blind design, 1 mg ACTH or placebo was injected into 16 professional cyclists. They cycled for 1 h on a bicycle ergometer at a submaximal level, defined as 60% of maximal performance on a pretest with a load increase of 50 W per minute. After 1 h, load was increased by 10 W per minute until exhaustion. No increase of maximal performance was observed with ACTH, either on the day of drug intake, or on the following day, although substantial increases were measured in physiological variables such as cortisol, glucose, and white corpuscle concentrations. Feelings of fatigue, which were continuously self-rated, were diminished only during submaximal performance. The present technique of systematically distinguishing between physiological, psychological, and performance measurements could help in explaining the persistent belief in the performance enhancing properties of ACTH and other doping substances.

Adrenocorticotropic Hormone↗
PubMed1995

Effect of amphetamine on long-term retention of verbal material.

A series of five experiments was conducted to investigate the temporal aspects of human memory consolidation of symbolic material through the administration of amphetamine. Subjects had to recall or recognise unrelated words from a previously presented list. The first experiments support the conjecture, based on animal studies, that amphetamine enhances long-term memory performance. Subsequently, enhancement is demonstrated with oral administration before learning, as well as with intramuscular injection after learning. It is shown that improved recall cannot be explained solely by general arousal or attentional processes, but must be due to consolidation. By introducing different test delays we show that consolidation of symbolic material can be modulated by amphetamine during the 1st hour after learning. In a final experiment we demonstrate that the memory enhancement applies to recall as well as to recognition. The implications of the present results are discussed in the context of recent research on LTP processes.

Administration, Oral↗
PubMed1993

Amphetamine enhances human-memory consolidation.

Although it is generally accepted that CNS stimulants have enhancing effects on long-term storage processes in laboratory animals, little is known about their influence on human learning. We report a series of experiments with free recall of lists of unrelated words, demonstrating a significant enhancement on long-term retention after amphetamine administration. A gradual increase of recall was observed up to 1 h after learning, remaining stable for at least 3 days, after oral administration before learning as well as intramuscular injection after learning. The results show that research on humans with drug-induced memory-enhancement techniques is necessary to supplement the animal studies for the understanding of the mechanisms involved in information consolidation.

Amphetamine↗