Twenty-four-hour beta-endorphin secretory pattern in stroke patients

BACKGROUND AND PURPOSE

Abnormalities of hypothalamo-pituitary-adrenocortical axis function have been observed frequently in stroke patients. The aim of this study was to investigate plasma beta-endorphin and cortisol 24-hour secretory patterns in patients early after stroke and in the convalescent period to evaluate a possible influence of brain damage on hormonal circadian pattern.

METHODS

Patients (n = 15; age, 46 to 75 years) were evaluated in the first 24 hours and 10 days after hospital admission for ischemic cerebral stroke and compared with 15 age- and sex-matched normal subjects. Blood samples for beta-endorphin and cortisol determination were drawn every 4 hours from 8 AM to 8 PM and every 2 hours from midnight to 6 AM.

RESULTS

Mean 24-hour beta-endorphin and cortisol levels, recorded in the acute phase, were significantly (P < .05) higher than those recorded in normal subjects; circadian rhythm was not demonstrable for either hormone. In the convalescent period, plasma cortisol 24-hour mean values and circadian rhythm returned to the normal range, whereas the plasma beta-endorphin 24-hour mean values and circadian rhythm did not.

CONCLUSIONS

Cerebral stroke induces abnormalities of beta-endorphin and cortisol circadian secretion. Whereas cortisol abnormalities are transient, those of beta-endorphin last longer. The dissociation between beta-endorphin and cortisol 24-hour secretory patterns might potentially serve as a marker of psychoneurological abnormalities occurring after stroke.

The effects of sumatriptan on pituitary secretion in man

Sumatriptan, a new antimigraine drug with high affinity and selectivity for certain 5-hydroxytryptamine (5-HT1D) receptor subtypes, was administered to 12 normal subjects, in order to investigate the effects of 5-HT receptor activation on anterior pituitary secretion. Sumatriptan increased plasma growth hormone (GH) levels from 2.5 +/- 0.5 mIU/l in basal conditions to 17.3 +/- 2.6 mIU/l 30 min after administration of the drug. After pre-treatment with cyproheptadine, an anti-serotoninergic drug known to inhibit GH secretion, the mean integrated sumatriptan-induced GH response decreased from 14.8 +/- 3.9 muI/l*hr to 3.7 +/- 1.7 mIU/l*hr. Sumatriptan administration did not have any effect on the secretion of the other anterior pituitary hormones. It is concluded that sumatriptan selectively increases GH secretion in man, but the exact nature of the receptors involved is not yet known.

Sumatriptan does not affect vasopressin secretion in humans

The aim of the study was to investigate the effects of a new serotoninergic drug, sumatriptan, on arginine vasopressin secretion in humans. Plasma vasopressin concentrations were determined in eight healthy volunteers, before and after administration of 6 mg of sumatriptan, or placebo. No changes in hormone levels were found after sumatriptan or placebo administration. The results suggest that in humans serotoninergic mechanisms, which modulate vasopressin secretion, do not involve the serotonin receptor activated by sumatriptan.

Sex hormones and sex hormone-binding globulin in males with chronic viral hepatitis during recombinant interferon-alpha 2b therapy

The effect of long-term treatment with recombinant interferon-alpha 2b (IFN-alpha 2b) on luteinizing hormone (LH), testosterone, free testosterone, and sex hormone-binding globulin (SHBG) was evaluated in 7 male patients suffering from chronic viral hepatitis. The drug was given three times a week for 6 months in a single standard dose of 3 x 10(6) units. Hormone evaluations were performed in basal conditions and every 2 months for 12 months. Serum testosterone values decreased after IFN treatment, reaching the lowest levels at the 6th month. However, testosterone values did not fall below the normal range. Serum SHBG concentrations, which were above the normal range in basal conditions, also decreased after IFN. Serum-free testosterone and LH concentrations did not change during IFN therapy. IFN-alpha 2b at the dose and schedule employed was not responsible for any measurable imbalance in male sex hormones.

Long term therapy with recombinant interferon alpha 2 b in patients with chronic hepatitis C: effects on thyroid function and autoantibodies

Twelve anti HCV-positive patients (8 males and 4 females; 37-62 yrs) suffering from chronic active viral hepatitis have been evaluated in order to determine serum thyroid hormones and autoantibody pattern during recombinant interferon alpha 2b (IFN-alpha 2b) therapy. The interferon was given subcutaneously three times per week for six months in a single standard dose of 3 MU. For a further six months 5 patients (Group A) received the same interferon at 1MU dose three times per week and 7 (Group B) had no treatment. Serum T3, T4, FT4, TBG, TSH, TGAb and TMAb were determined on serum collected before the start of the treatment and every month for 12 months thereafter. Except for one case, in which a transient reduction in thyroid hormone values and an increase in TSH levels was recorded, none of the patients studied showed a significant variation of serum hormonal parameters or appearance of pathological TGAb and/or TMAb levels. The data indicate that the administration of recombinant IFN-alpha 2b to HCV positive chronic active hepatitis patients at the dose and schedule employed in the present study may result in a reduction in the incidence of thyroid dysfunction related to the IFN therapy.

Calcitonin and beta-endorphin secretion

Calcitonin is a peptide hormone secreted by the C-cells of the thyroid gland. This hormone mainly acts in preventing bone resorption. Furthermore, calcitonin is involved in other biological actions, and in particular it is able to relieve pain independently of its peripheral effects on bone. Here, we examine the possible mechanisms of calcitonin-induced analgesia, with particular regard to the opioid system involvement. Several studies in animals and in humans demonstrate that calcitonin increases plasma beta-endorphin levels, acting at the hypothalamic and/or at the pituitary level, either directly or indirectly, through monoaminergic neurotransmitters. However, this calcitonin-induced beta-endorphin release has not always been observed. These different results are discussed, and a possible implication of sex and/or calcitonin dose employed has been examined. We conclude that the analgesic effects of calcitonin are multifactorial, and beta-endorphin plays its own specific role.

Thyroid hormones and atrial natriuretic hormone secretion: study in hyper- and hypothyroid patients

Plasma atrial natriuretic hormone (ANH) values were evaluated in 28 hyperthyroid patients and in 11 hypothyroid patients and compared with 20 healthy subjects. In hyperthyroid patients plasma ANH basal levels were significantly (p less than 0.01) higher (14.2 +/- 1.6 pmol/l) than in controls (7.8 +/- 0.4 pmol/l) and in hypothyroid patients (6.4 +/- 0.3 pmol/l). No significant differences were found between controls and hypothyroid patients. The propranolol-induced decrease in heart rate in hyperthyroid patients did not significantly affect the plasma ANH values. Conversely, after the methimazole-induced euthyroidism a return within the normal range of ANH values was observed. The thyroxine replacement in hypothyroid patients determined a small but significant (p less than 0.05) increase in plasma ANH values. Observed data suggest that in humans thyroid hormones may influence plasma ANH concentrations independently of their effect on heart rate.

Twenty-four-hour beta-endorphin secretory pattern in Alzheimer's disease

A chronobiological study was carried out in 6 male patients (67-71 years), suffering from Alzheimer-type dementia (ATD) and 6 male patients (52-74 years) suffering from multi-infarct dementia (MID), to evaluate their 24-hour beta-endorphin and cortisol secretory patterns. Six healthy male adults (28-37 years) and 6 healthy elderly male subjects (78-84 years) constituted the control groups. Blood samples were drawn every 4 h from 8.00 to 20.00 h and every 2 h from 24.00 to 6.00 h. Mean 24-hour beta-endorphin levels were significantly (p < 0.05) higher in the ATD patients (39.2 +/- 1.5 ng/l) than in the other groups (33.8 +/- 1.1, 30.1 +/- 1.6 and 33.2 +/- 1.1 ng/l in the elderly subjects, the adults and the MID patients, respectively). The circadian rhythm was absent in the ATP patients, in the elderly subjects and the MID patients. No differences in plasma cortisol circadian rhythm were observed among the four groups. Our data indicate that changes in circulating beta-endorphin concentrations and circadian pattern may be due to the aging process.

Effects of ursodeoxycholic acid (UDCA) on serum liver damage indices in patients with chronic active hepatitis. A double-blind controlled study

The effects of ursodeoxycholic acid (UDCA, 450 mg daily) in patients with histologically proven chronic active hepatitis (CAH) have been evaluated in a randomized, double-blind, placebo-controlled study. Twenty-six patients with serum alanine aminotransferase (ALT) values at least twice the normal upper limit in two of three pre-treatment tests received UDCA or a placebo for twelve weeks. In all UDCA-treated patients, serum aspartate amino-transferase (AST), ALT, gamma-glutamyl transpeptidase (GGT) and alkaline phosphatase (AP) fell significantly after 4 weeks of treatment. There was a further decrease at the end of therapy, as well as a small but significant fall in total serum bilirubin. Conversely, 4 weeks after suspension of therapy, serum enzyme levels had increased, reaching values not much lower than those recorded before treatment. Total serum protein, albumin and gamma-globulin did not change after UDCA treatment. In the placebo group no significant variation in the test results were found. The results indicate that UDCA therapy in CAH, as has been observed in primary biliary cirrhosis and primary sclerosing cholangitis, is able to improve several indices of liver damage, without producing any toxic adverse effects.

Plasma somatostatin response to an oral mixed test meal in cirrhotic patients

Ten patients with non-alcoholic cirrhosis and ten control subjects were studied in basal conditions and after ingestion of a standard mixed test meal. Plasma somatostatin, blood glucose, plasma insulin, C-peptide and glucagon were determined before and 15, 30, 45, 60, 90, 120 and 180 min after the start of the meal. Basal somatostatin levels in patients (31.9 +/- 1.8 ng/l) were significantly higher (p less than 0.01) than in controls (12.5 +/- 0.9 ng/l). The time-course of the somatostatin secretory response after the meal was similar in the two groups, but the increase, evaluated as incremental area above baseline, was significantly smaller (p less than 0.01) in cirrhotics (804 +/- 134 ng/l per min) than in controls (1482 +/- 149 ng/l per min). Data indicate that elevated basal plasma somatostatin concentrations in cirrhosis may be consequent to elevated gastrointestinal and/or pancreatic secretion, whereas the blunted somatostatin response to the mixed test meal may derive from the hyperinsulinemia which occurs in the postprandial period.

Metoclopramide increases plasma but not cerebrospinal fluid vasopressin levels in man: study in hydrocephalic patients

Arginine vasopressin (AVP) concentrations were determined in plasma and in cerebrospinal fluid (CSF) in 8 adult male patients suffering from hydrocephalus of various etiologies, before and after intravenous administration of 10 mg metoclopramide. Metoclopramide was able to increase the plasma (2.6 +/- 0.2 ng/l in basal conditions and 6.1 +/- 0.6 ng/l at 30 min) but not the CSF AVP levels. The results suggest that the neurons which secrete AVP into the CSF may be functionally different from those secreting into the peripheral circulation.

Influence of suckling on plasma concentrations of somatostatin, insulin and gastrin in lactating women

The effects of suckling on plasma somatostatin, insulin and gastrin values were evaluated in eight nursing women on the 3rd to 4th day postpartum. Plasma prolactin levels were also determined. Prolactin levels increased in response to suckling, as expected. Insulin levels also rose, whereas somatostatin and gastrin concentrations did not change after suckling. It is possible that the suckling-induced hyperinsulinemia blunts the somatostatin response to suckling in humans.

Twenty-four-hour secretory pattern of vasoactive intestinal polypeptide in the elderly

A chronobiological study was carried out in 8 elderly male subjects (74-85 years) to evaluate the 24-hour vasoactive intestinal polypeptide (VIP) secretory pattern. Eight young adult males (21-32 years) made up the control group. Blood samples were drawn from each subject every 2 h during the day and hourly during the night for a 24-hour period. Mean 24-hour VIP values in elderly (21.1 +/- 0.3 pg/ml) and young adults (19.1 +/- 0.3 pg/ml) did not differ statistically, but daytime VIP values observed in elderly subjects (21.4 +/- 0.5 pg/ml) were higher (p less than 0.05) than those recorded in young adults (17.5 +/- 0.5 pg/ml). The young adults showed significant (p less than 0.05) circadian VIP fluctuations with highest values during the nighttime, while the elderly subjects did not. An age-related decreased activity of the peripheral neuronal VIP-ergic network is hypothesized.

Plasma beta-endorphin concentrations during suckling in lactating women

Beta-endorphin appears to be involved in the hormonal response to suckling in some animals. The peripheral secretory patterns of beta-endorphin, prolactin and cortisol were investigated in serial venous blood samples taken during suckling from eight healthy women who were breast-feeding on the third or fourth day of the puerperium. Plasma levels of prolactin and beta-endorphin increased significantly during suckling reaching a peak after 20 min, levels of cortisol remained unaffected. It is suggested that the increased beta-endorphin derives from an extra-hypophyseal source.

Plasma beta-endorphin, ACTH and cortisol secretion in man after nasal spray administration of calcitonin

Beta-endorphin, ACTH and cortisol secretion were measured in twelve healthy adult males after nasal spray administration 200 IU salmon calcitonin. A significant increase in plasma beta-endorphin, from 19.2 ng/l under basal conditions to a peak of 27.1 ng/l at 30 min was recorded. Plasma ACTH and cortisol were not affected. In individual subjects the beta-endorphin level was increased in eight of the twelve, ACTH rose in three and cortisol did not change in any of them. The data indicate that calcitonin induced a beta-endorphin increase independent of enhanced corticotrophin-cortisol release.

Plasma somatostatin and vasoactive intestinal polypeptide responses to an oral mixed test meal in obese patients

Ten obese and 10 control subjects were studied in basal conditions and after ingestion of a standard mixed test meal. Blood glucose, insulin, somatostatin (SLI) and vasoactive intestinal polypeptide (VIP) concentrations were determined before and 30, 60, 90, 120, 180 and 240 min after the start of the meal. Basal SLI levels in the obese (14.4 +/- 0.7 ng/l) were not significantly different from those in the controls (15.5 +/- 0.8 ng/l), whereas after the meal a blunted secretory response was recorded. Baseline plasma VIP levels were higher in the obese (29.7 +/- 1.5 ng/l) than in the control subjects (19.8 +/- 1.3 ng/l) and, similarly to the controls, were unaffected by meal ingestion. Data suggest that in the course of obesity an enhanced VIP secretion in association with a diminished SLI responsiveness to meals occurs.

Diurnal changes of plasma and cerebrospinal fluid somatostatin and 24-h growth hormone secretory pattern in man. A study in hydrocephalic patients

Somatostatin concentration was determined in plasma and in cerebrospinal fluid during a 24-h period in 7 male patients suffering from hydrocephalus of differing aetiologies. Blood and ventricular cerebrospinal fluid samples were taken every 2 h during the day (08.00-22.00 h) and every hour during the night (24.00-07.00 h). Simultaneously, plasma growth hormone levels were also evaluated. Plasma SRIH levels showed significant circadian variations with highest values in the daytime and lowest values during the night. Cerebrospinal fluid SRIH did not show any significant time-related circadian changes. Plasma GH levels showed the well-known circadian pattern in the majority of patients. No significant correlation was found between the plasma GH and plasma or cerebrospinal fluid SRIH values recorded during the 24-h period. Results suggest that peripheral SRIH does not play any major role in the control of the 24-h GH secretory pattern in man.

Hormonal pattern and testicular histology in patients with prostatic cancer after long-term treatment with a gonadotropin-releasing hormone agonist analogue

Seven patients suffering from prostatic cancer were treated with a depot form of D-Trp-6-luteinizing hormone-releasing hormone (LH-RH), a LH-RH agonist analogue (3 mg i.m. every 28 days) for a period of 24-32 months. The peptide induced a sharp and long-lasting inhibition of both gonadotropin and testosterone secretion. A sustained suppression of pituitary and testicular function was observed 40 days after the treatment was suspended. Testicular biopsies performed in all patients showed a marked impairment of Leydig cell mass and a complete spermatogenic arrest with a tubular derangement and fibrosis. Results indicate that the long-term continued gonadotropin-releasing hormone agonist analogue therapy induces not only a functional inhibition of testicular androgenesis but also anatomical testicular damage whose reversibility does not seem to be probable.

Diurnal pattern of plasma and cerebrospinal-fluid vasopressin levels in hydrocephalic patients: absence of a circadian rhythm and of a correlation between plasma and cerebrospinal-fluid variations

The arginine vasopressin (AVP) concentrations were determined in plasma and in cerebrospinal fluid (CSF) during a 24-hour period in 7 male patients suffering from hydrocephalus of differing etiologies. Blood and ventricular CSF samples were simultaneously collected every 2 h during the day (08.00-22.00) and every hour during the night (24.00-07.00). In both plasma and CSF, the AVP levels did not show significant time-related circadian variations. No significant correlation was found between the plasma and CSF AVP values during the 24-hour period. The data obtained indicate the absence of the plasma and CSF AVP circadian rhythm in hydrocephalic patients and suggest that in these patients, and possibly in healthy humans, physiological stimuli which are able to induce variations in the plasma AVP concentration during daily life do not alter the CSF AVP content.

Sustained impairment of pituitary and testicular function in prostatic cancer patients treated with a depot form of a GnRH agonist

Seven patients suffering from prostatic cancer were treated with a slow-release D-Trp-6-LHRH preparation for a period of 24-32 months. LH, FSH, PRL and testosterone levels were evaluated before and at the end of treatment and then 40 days later. Baseline and GnRH-, TRH-, and HCG-stimulated hormonal values decreased after treatment. The possibility that a long-term treatment with GnRH analogues induces a sustained suppression of pituitary and testicular function is suggested.

Twenty-four-hour beta-endorphin secretory pattern in the elderly

A chronobiological study was carried out in seven elderly male subjects (78-84 years) to evaluate the 24-h beta-endorphin secretory pattern. Seven young adult males (28-37 years) made up the control group. Blood samples were drawn every four hours from 08.00 to 20.00 h and every two hours from 24.00 to 06.00 h. ACTH and cortisol levels were also determined in the same plasma samples. Mean 24-h beta-endorphin values in the elderly (32.6 +/- 1.1 ng/l) and in the young adult male subjects (29.5 +/- 1.4 ng/l) did not differ statistically, but the circadian rhythm was absent in the elderly subjects. In the elderly, plasma ACTH and cortisol concentrations showed a circadian rhythm similar to that observed in the adult subjects. However, in the elderly patients, in contrast to that in the adult subjects, the multilinear regression analysis did not show any statistically significant correlation between the beta-endorphin, ACTH and cortisol 24-h plasma concentrations.