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Biomedical subjects

G Giucastro

Publications and source records attributed to G Giucastro.

7 recordsLinked to original sources

GABAergic function in detoxified heroin addicts: relationship to anxiety disorders.

The function of the GABAergic system was examined in 20 subjects with heroin dependence and abuse, 2 months after detoxification, and in 10 healthy volunteers, by measuring the growth hormone (GH) response to a challenge with the GABA B receptor agonist baclofen. Ten heroin addicts had comorbid anxiety disorder (Group A), while the other ten had heroin addiction uncomplicated by Axis I and II psychopathologies (Group B). GH responses to baclofen stimulation of Group A patients were significantly blunted, while those of Group B subjects did not differ from responses of healthy volunteers. Our data show that the function of the GABAergic system is impaired only in heroin addicts with comorbid anxiety disorders (anxious cluster), suggesting that the GABA system is not persistently influenced by prolonged exposure to opioid receptor stimulation.

Adult↗

Neurotransmitter-hormonal responses to psychological stress in peripubertal subjects: relationship to aggressive behavior.

The relationship between different degrees of normal aggressiveness (low, medium, high) and neurotransmitter-neuroendocrine responses to the administration of psychologically stressful tests (Mental Arithmetic, Stroop Color Word Interference task, Trial Social Stress test) was examined in thirty male peripubertal junior school adolescents. Plasma concentrations of norepinephrine (NE), epinephrine (EPI), ACTH, cortisol (CORT), growth hormone (GH), prolactin (PRL) and testosterone (T) were measured immediately before the beginning of the tests and at their end, 30 min later. High-normal aggressiveness have been found associated with significantly higher basal concentrations of NE, ACTH, PRL, and T and with a significant increase of GH responses to the stressful stimuli.

Adolescent↗

Neuroendocrine responses of healthy volunteers to 'techno-music': relationships with personality traits and emotional state.

A variety of studies reported psychological and physiological effects of music. Different types of music have been found to induce different neuroendocrine changes. The aim of the present experiment was to investigate the possible combination of emotional and endocrine changes in response to techno-music and to define personality variables as predictors of respective changes. Sixteen psychosomatically healthy subjects (18- to 19-year-olds, eight males and eight females) were exposed, in random order, to techno-music or to classical music (30 min each). Plasma norepinephrine (NE), epinephrine (EPI), growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH) cortisol (CORT), beta-endorphin (beta-EP) concentrations and changes of emotional state were measured in basal conditions and after the experimental trials with two different types of music. Techno-music was associated with a significant increase in heart rate, systolic blood pressure and significant changes in self-rated emotional states. A significant increase was observed in beta-EP, ACTH, NE, GH and CORT after listening to techno-music. Classical music induced an improvement in emotional state, but no significant changes in hormonal concentrations. No differences between male and female subjects' responses to music have been found. Plasma levels of PRL and EPI were unaffected by techno- and classical music. Changes in emotional state and NE, beta-EP and GH responses to techno-music correlated negatively with harm avoidance scores and positively with the novelty-seeking temperament score on the Cloninger scale. Listening to techno-music induces changes in neurotransmitters, peptides and hormonal reactions, related to mental state and emotional involvement: personality traits and temperament may influence the wide inter-individual variability in response to music.

Adolescent↗

Serotonergic function after (+/-)3,4-methylene-dioxymethamphetamine ('Ecstasy') in humans.

(+/-)3,4-Methylene-dioxymethamphetamine (MDMA, or 'Ecstasy') effects on serotonin system function and behaviour in humans are unclear. Fifteen MDMA users, who did not have other drug dependencies or alcohol abuse, and had not used other drugs for prolonged periods, and 15 control individuals were included in a study to assess the biological and psychological changes after chronic use of MDMA. Prolactin and cortisol responses to D-fenfluramine challenge, clinical psychobehavioural changes, personality characteristics, including mood, aggressiveness and temperamental aspects, were evaluated 3 weeks after MDMA discontinuation. MDMA users had significantly reduced prolactin and cortisol responses in comparison with control individuals (p < 0.001 and p < 0.005, respectively). Dysphoria and mood changes were exhibited in seven individuals, tiredness in five and sensation-seeking behaviour in twelve at the clinical evaluation. Significantly higher scores were found in MDMA individuals than in control individuals for Minnesota Multiphasic Personality Inventory subscale for Depression, for Buss Durkee Hostility Inventory direct and guilt subscales, for Hamilton Depression Rating Scale and for novelty-seeking Tridimensional Personality Questionnaire subscale. Prolactin responses to D-fenfluramine stimulation area under the curve among MDMA users were negatively correlated with direct aggressiveness scores for Buss Durkee Hostility Inventory; a negative correlation between prolactin responses and novelty-seeking scores was also evidenced among MDMA users. These data suggest an association between serotonin system impairment and MDMA use in humans; in interpretation of these results, the possibility that serotonin deficit in MDMA individuals was partially related to a premorbid condition, in relationship with novelty-seeking behaviour and mood disorders, can not be excluded.

Adolescent↗

Neurotransmitter-neuroendocrine responses to experimentally induced aggression in humans: influence of personality variable.

Aggressiveness was experimentally induced in 30 psychophysically healthy male subjects, 18-19 years old, divided into 15 cases with low normal and 15 with high normal basal aggressivity. Plasma norepinephrine (NE), epinephrine (EPI), growth hormone (GH), prolactin (PRL), cortisol (CORT) and testosterone (Te) concentrations were measured in basal conditions and during experimentally induced aggressiveness. Basal Te and stimulated NE, GH and Cort levels were higher in subjects with high-normal than in those with low-normal aggressiveness, suggesting that the functional tonus of the NE system and of the NE-dependent hormonal axes might be a modulator of the behavioral parameter.

Adolescent↗

Serotonergic function in mothers of opioid addicts: correlation with comorbid depression.

The serotonergic (5-HT) function of 36 mothers of heroin addicts, of whom 16 subjects were without psychopathological features (group A) and 20 subjects had major depressive disorders (group B), as well as 10 age- and sex-matched healthy controls, was examined by L-D-fenfluramine stimulation of secretion of prolactin (PRL) and cortisol. The subjects' addict relatives were also tested for personality features and hormonal responses to L-D-fenfluramine. The PRL and cortisol responses to the stimulus were normal in mothers of group A, and blunted in mothers of group B. A high frequency (70%) of heroin addicts with comorbid depression was found among the sons of group B mothers. The sons of depressed mothers showed reduced PRL and cortisol responses to fenfluramine. A significant direct correlation has been demonstrated between the PRL areas under curves (AUC) of mothers and sons in response to the 5-HT agonist. Our data suggest that genetic 5-HT impairment is not involved in the pathogenesis of heroin addiction or codependence per se, and is probably linked to the presence of familial depression in comorbidity with the addictive disorder.

Adult↗

Role of blood pressure in the natriuretic response to acute calcium channel blockade in humans.

Glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and renal excretion of sodium and lithium were measured before and after acute oral administration of 20 mg nifedipine in 19 essential hypertensive patients. In 10 of them, with a diastolic pressure less than 105 mm Hg, nifedipine resulted in a decrease in mean blood pressure toward normal (109 +/- 2 to 97 +/- 2, p less than 0.001), a 27% increase in ERPF (p less than 0.001), no change in GFR, and an increase in fractional sodium excretion (28%, p less than 0.001). In nine subjects with a diastolic pressure greater than or equal to 105 mm Hg, nifedipine produced a decrease in mean blood pressure (133 +/- 6 to 117 +/- 4, p less than 0.001), which however remained higher than in mild hypertensives (p less than 0.001). ERPF rose by 29% (p less than 0.001), GFR remained unchanged, and fractional sodium excretion definitely increased more than in mild hypertensives (126%, p less than 0.001), as did fractional lithium excretion, used as an estimate of proximal tubular sodium handling. Acute nifedipine produces renal vasodilation in hypertensives, but with a greater natriuretic response in those subjects whose blood pressure remains elevated. Thus, acute natriuresis following nifedipine administration is largely dependent on the interaction between changes in arterial pressure and renal hemodynamics.

Blood Pressure↗