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Biomedical subjects

G Gerra

Publications and source records attributed to G Gerra.

At least 73 records · Page 4Linked to original sources
PubMed1992

Sex-related responses of beta-endorphin, ACTH, GH and PRL to cold exposure in humans.

To establish a possible different reaction between the male and the female to short-term exposure to cold, thermal, cardiovascular and pituitary hormonal responses to cold stress were measured in eight normal men and eight women (ages 19-24). The women were eumenorrheic and were tested in the follicular phase. Each subject, lightly clad, was required to remain for 30 min in a room at an ambient temperature of 25 degrees C followed by a 30 min period in a cold room at 4 degrees C. A month later, control tests were carried out at a constant 25 degrees C temperature for 1 h in the same subjects. Skin temperature, heart rate, blood pressure and plasma levels of beta-endorphin, ACTH, cortisol, GH and PRL were measured before and after cold exposure in the two groups. Before the test, all examined parameters were similar in the two groups. During cooling, blood pressure rose and pulse rate decreased significantly in the men, but not in the women, whereas skin temperature dropped in both groups. However, after cold exposure skin temperature was significantly lower in the women than in the men. A slight, but not significant increase in beta-endorphin, ACTH, cortisol and GH levels was observed after cooling in the men, whereas the women showed significant increments of these hormones. When values of skin temperature were combined with the differential (after minus before cold test) hormonal values, significant negative correlations were found for beta-endorphin, ACTH, cortisol and GH.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1992

Long-lasting impairment of neuroendocrine response to psychological stress in heroin addicts.

Performance in a vigilance task and the associated neuroendocrine changes during the performance in the task were examined in healthy subjects and in three groups of male heroin-addicts both before undergoing rehabilitation programmes and at various intervals from withdrawal (5 days, 1 to 2 mon, and 3 to 48 mon, respectively). Plasma levels of ACTH, beta-endorphin (EP) and prolactin (PRL) were measured every 10 min before and during performance. In drug addicts, simple reaction times never showed any significant difference as compared to control values. Despite similar baseline levels, ACTH exhibited a markedly depressed response to psychological testing in drug-addicts as compared to controls. Whereas a three-fold increase in ACTH was observed in 'normal' subjects during the performance (from 17 to 54 ng/l), mean values from drug-addicts remained unchanged. EP levels showed a wide scatter of individual values and inconsistent time courses over performance testing: after short-term abstinence, EP showed a three-fold increase over baseline control values but, contrary to what seen in 'normal' subjects, no changes over time were recorded. After long-term abstinence, basal EP was close to control values, but its increase during the testing period was still blunted. PRL levels decreased over the testing period both in controls and in heroin addicts. Thus, despite the lack of obvious signs of neurotoxicity, drug abusers show neuroendocrine changes consistent with a long-lasting selective impairment of the hypothalamic modulation of pituitary secretion.

Adrenocorticotropic Hormone↗
PubMed1990

Salmon calcitonin given by nasal spray or by injection does not increase beta-endorphin levels in normal men.

It has been suggested that the analgesic action of calcitonin (CT) might involve a stimulation of beta-endorphin (beta-EP) release. To verify whether salmon CT modifies the circulating levels of beta-EP, and whether the route of administration plays any role in this response, we have studied 10 healthy male volunteers, aged 30-40 yr. Each of them was studied on 4 different days, after administration of placebo or salmon CT (100 UI) by the intravenous, intramuscular and nasal route, in random order. Ionized calcium tended to decrease, especially after intravenous CT, but there was no change in plasma beta-EP levels, regardless of the route of administration. It is therefore unlikely that circulating beta-EP mediates any biological effect of CT.

Administration, Intranasal↗
PubMed1990

Metyrapone effects on beta-endorphin, ACTH and cortisol levels after chronic opiate receptor stimulation in man.

The aim of this study was to evaluate beta-endorphin, ACTH, and cortisol plasma levels during metyrapone administration in man after chronic opioid receptor stimulation. Metyrapone (750 mg every 4 hr for 6 doses) was administered to ten male heroin addicts, who had been on a maintenance therapy with methadone for at least 6 months and to ten healthy sex- and age-matched volunteers. Before metyrapone administration the basal levels of cortisol and ACTH were significantly decreased in addicts as compared to normal controls, while plasma beta-endorphin was not different. The response of beta-endorphin and ACTH to metyrapone administration was significantly blunted in addicts (p less than 0.01). These results suggest that the chronic stimulation of opiate receptors can impair the function of the anterior pituitary gland.

Adrenocorticotropic Hormone↗
PubMed1990

Circulating opioid peptides during thermal stress.

In the present study we have examined the response of endogenous opiates (beta-EP and Met-enk) and ACTH to a particular type of thermal stimulus such as sauna in 8 young healthy subjects. Sauna-induced hyperthermia resulted in an increase of plasma beta-EP and ACTH, but appeared to have no significant effect on circulating Met-enk. The different responses of ACTH, beta-EP and Met-enk to heat exposure indicate that hyperthermia represents a form of stress, which can trigger off a well-defined neuroendocrine reaction.

Adrenocorticotropic Hormone↗
PubMed1990

Impaired prolactin response to hyperthermia in heroin addicts.

The response of PRL, FSH and LH to sauna-induced hyperthermia was examined in 8 male former heroin addicts (studied after 14-24 days of abstinence) and 8 age- and sex-matched control subjects. The basal levels of PRL tended to be higher in former drug users than in control subjects (p = 0.07). After sauna, there were no changes in the addict group, whereas a significant increase was observed in normal subjects (p less than 0.001). Baseline plasma LH and FSH levels were significantly lower in former drug users (p = 0.02), but no change was found after sauna in either group. These findings are consistent with the existence of a deficient adaptation to thermal stress in chronic drug users, even after a relatively short drug-free period.

Adolescent↗
PubMed1989

Endocrine effects of psychological stress associated with neurobehavioral performance testing.

Twenty-four healthy subjects were submitted to a computer-based performance evaluation system. The set of tests required sustained attention, and the last test was expressly designed to cause a moderate, acute psychological stress. Compared to baseline levels, both serum ACTH and beta-endorphins were increased after psychological testing in all subjects. Serum prolactin showed a slight and statistically nonsignificant decrease compared to baseline values. These results question the belief that psychological stress stimulates prolactin secretion, whereas it suggests that serum ACTH and beta-endorphins are reliable indicators of acute psychological stress.

Adrenocorticotropic Hormone↗
PubMed1989

Impaired ACTH and beta-endorphin response to sauna-induced hyperthermia in heroin addicts.

To evaluate the responses of circulating beta-endorphin, met-enkephalin and ACTH to sauna-induced hyperthermia, 8 male heroin addicts recently admitted to a therapeutic community and 8 age-matched normal subjects were examined. Compared with control subjects, heroin addicts showed 1. A decrease of the basal levels of beta-endorphin; 2. Absence of the normal increase of beta-endorphin and ACTH after sauna; 3. A lower increase in systolic blood pressure. It is concluded that an impairment of the adaptive response to stress may be present in heroin addicts, even after a relatively short drug-free period (14 days).

Adolescent↗
PubMed1987

[Homeostasis of blood glucose and abuse of exogenous opiates: evaluation of fructosamine and glycosylated hemoglobin].

The study was designed to assess glycaemic homeostasis in different situations of chronic stimulation of the opiate receptors by exogenous opiates. After an OGTT, levels of glycosylated haemoglobin (HbA1c) and serum fructosamine were measured in 3 groups of male drug addicts of comparable age. Group A consisted of 10 subjects undergoing substitution treatment with oral methadone. Group B consisted of 10 subjects addicted to intravenous injection of the syrup based methadone intended for oral administration. Group C consisted of 10 heroin addicts. Ten healthy subjects of the same age and sex were used as controls. Analysis of the results showed normal glucose tolerance in all groups with tendentially higher basal glycaemia levels in group B. HbA1c levels were significantly higher, though within normal limits, in group B than in either those receiving oral methadone (p less than 0.01) or the heroin addicts (p less than 0.01). The group B subjects also showed the highest fructosamine levels that were both well above normal limits and higher than those in the other groups in whom fructosamine levels were normal. The data therefore confirm normal glycaemia compensation in those taking oral methadone and in heroin addicts during the period considered. A new type of drug addiction involving the intravenous injection of methadone was also encountered. This produces an outstanding short-term change in glycaemic homeostasis and may well lead to future alterations in glucose tolerance.

Adult↗
PubMed1987

[Diabetes insipidus after selective pituitary adenomectomy. A case with late appearance].

Diabetes insipidus is a well-known complication of hypophyseal surgery. The case is described of a women presenting with evident polyuropolydipsic syndrome arising 9 years after transphenoidal hypophyseal adenectomy. The diagnosis insipidus diabetes was secondary to intrasellar scars revealed by a hypophyseal CAT scan. The unusually long interval between surgery and the onset of the syndrome is emphasised.

Adult↗
PubMed1985

Activation of PRL secretion by combined treatment with cyproterone acetate and ethinylestradiol.

Two groups of patients affected by idiopathic androgenization have been treated with ethinylestradiol (EE) associated with two different (high and low) dosages of cyproterone acetate (CA); the aim of this study was to evaluate the possible endocrine side effects at the pituitary level. After three and six months of treatment gonadotropins secretion appeared significantly inhibited with higher evidence for LH than for FSH and especially in the patients on high dose of CA. Nevertheless the most impressive finding was represented by the increase in PRL responses to TRH documented when higher doses of CA were employed without significant change in TSH secretion. The Authors suggest that such PRL hyperresponsiveness cannot be completely disregarded in the management of idiopathic androgenization.

Adult↗
PubMed1985

Effects of dopamine receptor stimulation on opiate-induced modifications of pituitary-gonadal function.

We evaluated the effects of the dopaminergic drug bromocriptine (Br) on prolactin (PRL), luteinizing hormone (LH) and testosterone (Te) levels in a homogeneous group of opiate addicts in a methadone maintenance program (20 mg twice daily). Basal blood levels of PRL, LH and Te were determined in 15 adult male drug addicts, before 30 and 60 days after Br administration (7.5 mg/day) was started. 15 healthy volunteers served as controls for the evaluation of basal values of the hormones. Before treatment PRL values were high, while LH and Te levels were lower than normal. 30 days later, PRL lowered significantly while LH and Te increased significantly. 60 days later, the blood hormone values were still significantly different from pretreatment values, and close to the normal range. This observation shows that Br, probably through an increase of dopaminergic tone, may counteract some effects of opiates on the hypothalamic-pituitary-gonadal axis.

Adolescent↗
PubMed1984

Effect of methadone on TSH and thyroid hormone secretion.

The hypothalamus-pituitary-thyroid function was studied in 15 male patients on chronic methadone treatment (40 mg/day). No significant variations of TSH, T4, T3 and rT3 levels were documented, either in basal conditions or after TRH stimulation; however a reduced TSH pituitary response was recorded in some patients (6 out of 15).

Adult↗
PubMedDate not supplied

[Effects of body weight changes on menarche and menstrual cycles in a group of adolescents].

In Italian girls (7-17 years-old) the effects of body weight on the onset of menarche and on menstruation were studied on the basis of measurements performed in 86 normally developed healthy girls (group 1), in 5 girls affected by precocious puberty (group 2), and in 9 girls with delayed puberty (group 3). Height and weight were evaluated at menarche in all groups, as well as 2 years later in groups 2 and 3. The results were transferred on the graphs proposed by Frisch for the American girls: at menarche 20% of group 1 girls were out of range; in group 2 all girls were in range; 33% of group 3 were below the 10th percentile. Two years later, all groups 2 and 3 girls but one were in range. These data do not confirm the role of body fat in determining the onset of the puberal process, while they support it in the maintenance of menses.

Adolescent↗