Acute and chronic hyperbaric oxygen exposure in humans: effects on blood polyamines, adrenocorticotropin and beta-endorphin.

Plasma beta-endorphin, adrenocorticotropin (ACTH) and blood polyamine (spermidine and spermine) concentrations were evaluated in healthy adult male athletes undergoing hyperbaric oxygen exposure for 10 days (2.8 atm, 100% O2, 60 min daily). In the "acute phase", corresponding to the first day of treatment, and in the "acute in the chronic phase", corresponding to the values obtained on the 5th and 10th days after 60 min of hyperbaric O2, both ACTH and beta-endorphin levels increased significantly, whereas no variations were observed for polyamine concentrations. In the "chronic phase", corresponding to the basal values of the 5th and 10th days of treatment, we found a different pattern. In fact, the concentration of polyamines showed a remarkable enhancement, while ACTH and beta-endorphin levels remained unchanged. No significant variations were observed during hyperbarism with air. These results demonstrate different modifications of polyamines and beta-endorphin and ACTH in subjects submitted to hyperbaric oxygen exposure.

Effects of chronic heroin abuse on bone and mineral metabolism.

Though the chronic use of opiates can modify several body functions, only a few data are available on the effects of opioid drugs on mineral metabolism. We have examined the possible consequences of chronic opiate abuse on bone mass, bone turnover and calcium metabolism in 13 male chronic heroin users, examined 1-2 days after the last administration of the drug (group A), 14 former male heroin addicts, examined 4-24 months after drug discontinuation (group B), and 22 healthy, age- and sex-matched control subjects. In group A, the vertebral bone mineral density (measured by Dual-Photon Absorptiometry) was significantly lower (p < 0.05) than in the control subjects, despite similar values of total body bone mineral, lean body and fat mass. Blood-ionised calcium and urinary calcium and hydroxyproline were significantly increased (p < 0.01), whereas parathyroid hormone was lower than in controls (p < 0.01). Bone alkaline phosphatase and osteocalcin, however, were not significantly different from the control values. LH and testosterone levels were low (p < 0.01 vs controls). In contrast, group B subjects did not show significant differences from the control group. The chronic abuse of opioid drugs may be associated with altered bone metabolism and reduced trabecular bone mass, attributable, at least in part, to gonadal deficiency. These alterations seem reversible after drug discontinuation.

Neuroendocrine response to psychological performance testing.

Neuroendocrine changes associated with performance testing requiring sustained attention were assessed in eight normal male subjects. To verify whether the hormonal pattern was modified by chronic stimulation of opiate receptors, eight heroin addicts also were studied. Reaction times were similar in normal and addict subjects. In normal individuals, consistent and significant increases in plasma ACTH and beta-endorphin and in urinary epinephrine and norepinephrine were observed, whereas serum prolactin (PRL) progressively decreased over the testing period. Despite maintained performance capabilities, heroin addicts showed a blunted response of ACTH and a paradoxical decrease in endorphin levels. As the normal subjects, both epinephrine and norepinephrine in urine showed the same significant increase over baseline values. Serum PRL showed a similar trend towards decreased values over the testing period in both groups.

Impaired PRL response to hyperthermia in alcoholic men.

The aim of this study was to evaluate the release of PRL to sauna-induced hyperthermia in 10 chronically alcohol-addicted male subjects after a few weeks of abstinence. In contrast with normal men the alcoholic men showed higher basal levels of PRL and the exposure to hyperthermic stress did not stimulate in PRL secretion. These results indicate that chronic alcohol abuse is associated with functional pituitary alterations similar to other states of addiction.

Chronic effects of marihuana smoking on luteinizing hormone, follicle-stimulating hormone and prolactin levels in human males.

The purpose of this investigation was to assess the chronic effects of marihuana smoking on the basal and stimulated secretion of the pituitary hormones luteinizing hormone (LH), follicle-stimulating (FSH) and prolactin (PRL). Ten male chronic marihuana users and 10 age- and sex-matched healthy volunteers were studied by measuring hormone levels before and after i.v. administration of thyrotropin releasing hormone (TRH) and gonadotropin releasing hormone (GnRH). The basal and stimulated levels of LH were reduced in marihuana users, whereas FSH and PRL levels and responses were not different from the control subjects. The chronic use of marihuana may selectively impair the hypothalamic control mechanisms regulating LH secretion.

ACTH and beta-endorphin responses to physical exercise in adolescent women tested for anxiety and frustration.

Thirty healthy adolescent women (age: 14 years), high school students without clinical signs of psychiatric or major affective disorders, received psychological and endocrinological examinations. Two psychological tests were used: the Anxiety Score Test for Adolescents and the Pictures Frustration Test for Adolescents of Rosenzweig. On the basis of the results of these tests, subjects were divided into two groups: A (n = 21), normal subjects; B (n = 9), subjects with evidence of anxiety (n = 1), frustration (n = 1), or both (n = 7). Plasma levels of adrenocorticotropic hormone (ACTH) and beta-endorphin were measured under basal conditions and after physical exercise (Step Test) in all subjects. Hormonal responses in groups A and B were compared. Basal concentrations of ACTH and cortisol were similar in the two groups, whereas basal beta-endorphin levels were significantly higher in group B than in group A. Exercise induced a slight but significant increase in plasma concentrations of both ACTH (32% increase) and beta-endorphin (60% increase) in group A. A striking increase in plasma ACTH (100% increment) and a slight increase of beta-endorphin (60% increment) levels were observed in group B after exercise. Absolute levels of ACTH and beta-endorphin after physical exercise were significantly higher in group B than in group A. These findings indicate increased levels of adrenocorticotropic and opioid activity in adolescent women with high scores on psychological measures of anxiety and frustration.

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)

Calcitonin nasal spray reduces opioid withdrawal syndrome without modification of endogenous opioid secretion.

It has been suggested that the well known analgesic effect of calcitonin (CT) may result from an enhanced secretion of opioid peptides. The purpose of this double-blind, controlled study was therefore to evaluate the effectiveness of CT on the opiate withdrawal syndrome. 20 drug addicts were randomly allocated to receive either 200 UI/day of salmon CT (n = 10) or placebo (n = 10) by nasal spray, after the abrupt withdrawal of low-dose methadone (20 mg/day). The severity of the withdrawal syndrome was evaluated by means of a score derived from a symptom check-list. Plasma beta-endorphin, glucose and insulin levels were measured before and after CT administration. The subjects treated with spray CT had significantly lower score than those treated with placebo. Beta-endorphin levels did not show any significant variation in both groups. An inhibitory action of CT on insulin secretion was observed. Our data suggested that CT might be considered a useful supportive measure for opiate withdrawal. CT action does not seem to involve the opioid system, but is probably mediated by a direct action on specific receptors or by a modulation of noradrenergic pathways.

Vertebral mineral content in diet-dependent and diet-independent hypercalciuria.

The vertebral mineral content was measured using dual photon absorptiometry in 41 calcium stone patients with idiopathic hypercalciuria. These patients had been previously divided into 2 groups (diet-dependent and diet-independent hypercalciuria) during a low sodium and low calcium diet. In some of the patients (11 with diet-dependent and 11 with diet-independent hypercalciuria) the vertebral mineral content was evaluated in relation to serum ionized calcium, intact parathyroid hormone, alkaline phosphatase and osteocalcin determined after a low sodium and low calcium diet. The vertebral mineral content, expressed as Z-VMD, was normal in diet-dependent and lower in diet-independent hypercalciuric stone patients (-0.30 +/- 1.19 versus -0.26 +/- 1.18, p less than 0.02). In 7 of 21 patients (33.3%) the vertebral mineral content was less than 2 standard deviations of the normal value, indicating a true involvement in bone metabolism. Serum intact parathyroid hormone and osteocalcin levels were not different from the controls in both groups, while alkaline phosphatase activity and ionized calcium were higher in diet-independent hypercalciuric patients. Serum ionized calcium was negatively correlated with bone vertebral density. The results suggest that an increased bone turnover may be a primary event in causing hypercalciuria in calcium stone patients unable to decrease urinary calcium to less than the calcium intake.

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.

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.

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.

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.

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).