Effect of Meprobamate on Catecholamine Excretion during Mental Stress

Constancy of Urinary Catecholamine Excretion

The constancy of adrenaline and noradrenaline excretion was estimated by calculating correlations between excretion rates of both hormones in four series of urine samples obtained from 15 Ss at 1-wk. intervals. The constancy of excretion rates was shown to be satisfactory for quantitative studies.

Relation between beta-adrenergic receptor density and lymphocyte proliferation associated with acute stress

The relations between acute changes in beta-adrenoreceptor density on lymphocytes and lymphocyte proliferation to a laboratory speech stressor were examined. Male participants either prepared and delivered a challenging speech task or read from a list of words. Participants engaged in the speech task, but not those involved in reading, exhibited significant increases in systolic blood pressure (an index of sympathetic nervous system arousal) and beta-adrenoreceptor density, accompanied by significant decreases in lymphocyte proliferation to pokeweed mitogen (PWM) but not concanavalin A (Con A). Increases in adrenoreceptor density significantly predicted decreases in lymphocyte activity in response to both mitogens. The increases in beta-adrenoreceptor density in the speech task condition occurred within 5 min after the baseline period, when participants were preparing for the speech task, but not yet speaking. These findings suggest that an acute stressor eliciting sympathetic nervous system activity can evoke rapid changes in beta-adrenoreceptor activity and decreases in mitogenic responses.

Catecholamine excretion, conscience function and aggressive behaviour

This report deals with a study--carried out among 46 12-17-year-old-boys--of the relationship between: (1) the excretion of waste products of catecholamines (methyladrenaline and methylnoradrenaline) and creatinine, (2) aggressive behaviour in a laboratory setting, and (3) data obtained via a conscience-function questionnaire. The hypothesis that aggressive behaviour is positively correlated with methylnoradrenaline excretion was confirmed. As far as the conscience-function questionnaire was concerned, three dimensions could be distinguished. Methyladrenaline and methylnoradrenaline excretion proved to be reversely related to one of them, indicated as the 'intropunitiveness-aggressiveness dimension'. Intropunitive subjects appeared to have a higher methyladrenaline and a lower methylnoradrenaline excretion than aggressive subjects. The aforesaid dimension also correlated significantly with creatinine excretion, a finding which led to the interpretation that aggressive people possess greater muscular strength than more intropunitively inclined people. However, no significant correlations between aggression scores and questionnaire scores were found. The results are discussed against the background of arousal theories of aggressive behaviour.

Performance decrement after intake of meprobamate as a function of task difficulty and learning level

The effect of 800 mg of meprobamate on performance in choice-reaction tasks of varying difficulty was examined. Comparisons between scores obtained in drug and placebo conditions showed that performance was progressively more impaired by the drug as task difficulty increased and progressively less impaired as learning level increased.