Plasma oxytocin levels and anxiety in patients with major depression

Cerebrospinal fluid and plasmatic levels of oxytocin (OT) have been found to change in mood disorders. In post-mortem studies, the numbers of OT-expressing neurons in the paraventricular nucleus have been reported to be increased. Moreover, OT is considered as an endogenous antistress hormone. It has also revealed antidepressive effects. OT may contribute to the dysregulation of the HPA system in major depression. The aim of the study was to assess a possible relationship between anxiety and plasma oxytocin (OT) levels in depressive patients. Severity of depression was estimated with the Hamilton Depression Rating Scale and anxiety by using the Spielberger State-Anxiety Inventory. Results showed a significant negative correlation between oxytocin and the scored symptoms depression (r=-0.58, p=0.003) and anxiety (r=-0.61, p=0.005).

Hemodynamic changes induced by laparoscopy and their endocrine correlates: effects of clonidine

OBJECTIVES

We investigated endocrine correlates of the hemodynamic changes induced by carbon dioxide pneumoperitoneum (PNO). We then studied whether clonidine might modulate the hemodynamic changes induced by PNO by reducing release of catecholamines and vasopressin.

BACKGROUND

Both mechanical and neurohumoral factors contribute to the hemodynamic changes induced by carbon dioxide PNO. Several mediators have been proposed, but no study has correlated hemodynamic changes with changes in levels of these potential mediators.

METHODS

We conducted two studies, each including 20 healthy patients scheduled for elective laparoscopic cholecystectomy. In the first study serial measurements of hemodynamics (thermodilution technique) were done during laparoscopy and after exsufflation. Plasma concentrations of cortisol, catecholamines, vasopressin, renin, endothelin and prostaglandins were measured at the same time points. In the second study patients were randomly allocated to receive 8 microg/kg clonidine infused over 1 h or placebo before PNO. Hemodynamics and plasma levels of cortisol, catecholamines and vasopressin were measured during PNO and after exsufflation.

RESULTS

Peritoneal insufflation resulted in a significant reduction of cardiac output (18+/-4%) and increases in mean arterial pressure (39+/-8%) and systemic (70+/-12%) and pulmonary (98+/-18%) vascular resistances. Laparoscopy resulted in progressive and significant increases in plasma concentrations of cortisol, epinephrine, norepinephrine and renin. Vasopressin plasma concentrations markedly increased immediately after the beginning of PNO (before PNO 6+/-4 pg/ml; during PNO 129+/-42 pg/ml; p < 0.05). The profile of vasopressin release paralleled the time course of changes in systemic vascular resistance. Prostaglandins and endothelin did not change significantly. Clonidine significantly reduced mean arterial pressure, heart rate and the increase in systemic vascular resistance. Clonidine also significantly reduced catecholamine concentrations but did not alter vasopressin and cortisol plasma concentrations.

CONCLUSIONS

Vasopressin and catecholamines probably mediate the increase in systemic vascular resistance observed during PNO. Clonidine before PNO reduces catecholamine release and attenuates hemodynamic changes during laparoscopy.

The neuroendocrine thymus: coexistence of oxytocin and neurophysin in the human thymus

Immunoreactive oxytocin and neurophysin were identified and measured by radioimmunoassay in human thymus extracts. Serial dilutions of extracts paralleled the appropriate standard curves. Thymus-extracted oxytocin and neurophysin eluted in the same positions as reference preparations on Sephadex G-75. Authenticity of oxytocin was confirmed by biological assay and high-performance liquid chromatography analysis. In most instances, thymus contents of oxytocin and neurophysin were far greater than those expected from known circulating concentrations and declined with increasing age. The molar ratio of oxytocin to neurophysin in thymus was similar to that found in the hypothalamo-neurohypophyseal system, which strongly suggested with the other data a local synthesis of oxytocin. These findings indicate the presence of neurohypophyseal peptides in the human thymus and further support the concept of a neuroendocrine function integrated in an immune structure.

Inhibitory effect of oxytocin on corticotrope function in humans: are vasopressin and oxytocin ying-yang neurohormones?

Oxytocin (OT) and vasopressin (VP) are very similar neurohypophyseal peptides. While VP is known as an ACTH stimulating factor synergistic to CRF since two decades, the inhibiting activity of OT, first demonstrated in the human, is now confirmed in various species including mouse and rat!It is likely that endogenous oxytocinergic system which can be activated by physiological and/or pharmacological manipulation can "buffer" the stress activated vasopressin-ACTH-cortisol action. Since VP and OT share also opposite action on cognitive function, those two "sister" neuropeptides might be considered as "ago-antagonist" or "ying-yang" neurohormones!

Serum melatonin and urinary 6-sulfatoxymelatonin in major depression

In this study, serum melatonin and urinary 6-sulfatoxymelatonin (aMT6s) were measured in 14 major depressive inpatients, compared to 14 matched controls according to age, gender, season and hormonal treatment in women. Moreover, the relationship between serum melatonin and urinary aMT6s levels was analysed in the two groups. Results indicated that the two groups of subjects showed a clear melatonin rhythm without significant difference in the mean level of melatonin or aMT6s, in the area under the curve of melatonin or in the melatonin peak. However, the time of the nocturnal melatonin peak secretion was significantly delayed in depressive subjects as compared to healthy controls. Moreover, the depressed patients showed urinary aMT6s concentrations enhanced in the morning compared to night time levels, while these concentrations were lowered from the night to the morning in the control group. These results suggest that the melatonin production is phase-shifted in major depression.

ISA, ISSAM, EAU, EAA and ASA recommendations: investigation, treatment and monitoring of late-onset hypogonadism in males

The new ISA, ISSAM, EAU, EAA and ASA recommendations on the investigation, treatment and monitoring of late-onset hypogonadism in males provide updated evidence-based information for clinicians who diagnose and treat patients with adult onset, age related testosterone deficiency.

Suppressed prolactin but normal neurophysin levels in cigarette smoking breast-feeding women

The hormonal responses to breast-feeding were studied during the first 3 post-partum weeks in ten women smoking more than fifteen cigarettes/day and in a control group. Basal PRL levels were significantly lower in smokers compared with non-smokers, but suckling induced acute increments in serum PRL and oxytocin-linked neurophysin, which were not influenced by smoking. The lactational pattern was normal, but smokers weaned their babies significantly earlier compared with non-smokers. Heavy cigarette smoking women have lower basal PRL levels and this may shorten the period of lactation.

Plasma AVP, neurophysin, renin activity, and aldosterone during submaximal exercise performed until exhaustion in trained and untrained men

The effect of intense muscular work (80% of maximal oxygen uptake) on responses of plasma hormones involved in electrolyte and water balance were measured in 14 male subjects. They were divided into three groups according to their maximal oxygen uptake and the duration of exercise performed until exhaustion: well trained subjects (group I), trained subjects (group II), and untrained subjects (group III). Pulmonary gas exchange, heart rate, rectal and skin temperature, and weight loss were measured as well as hematocrit and plasma and urine sodium and potassium concentrations. Rectal temperature increased significantly in all subjects after exhaustion. The variation of hematocrit was smallest and the weight loss greatest in the well-trained subjects. Plasma aldosterone, renin activity (PRA), vasopressin (AVP), and neurophysin (Np) displayed highly significant increases after exercise in all three groups: PRA was increased 4.5 times (p < 0.01), aldosterone 13 times (p < 0.05), Np 2.6 times (p pe 0.05), and AVP 4.8 times (p < 0.05). Nevertheless, there was no correlation between the changes in PRA and those in plasma aldosterone, nor between aldosterone and plasma sodium or potassium. At the urinary level, the only striking observation was that free water clearance tends to become positive after exercise. Our results provide evidence that this kind of exercise produces a highly significant increase in plasma levels of the hormones involved in electrolyte and water balance. They also indicate that it is among the well-trained subjects that sweat loss is highest though the hematocrit increase is the smallest; this suggests that water is shifted more efficiently from the extravascular compartment.

Cerebrospinal fluid neurophysins in affective illness and in schizophrenia

We studied the concentration of neurophysin I (hNPI) and II (hNPII), the hypothalamo-pituitary carriers of vasopressin and oxytocin, in CSF of depressed and schizophrenic patients and age matched controls. Mean hNPI values were lower and mean hNPII values greater in schizophrenics than in controls. Lower hNPI values were observed in unipolar patients than in controls. In bipolar patients however, higher hNPI values were present. Significantly higher hNPII values were observed in bipolar patients than in controls; no difference was present between unipolars and controls. A positive correlation was observed with age in controls and bipolars for hNPII. These data emphasize the interest of studying the neurohypophysal function in affective illness and in schizophrenia.

The neurohormonal thymic microenvironment: immunocytochemical evidence that thymic nurse cells are neuroendocrine cells

Thymic neuroendocrine cells were identified by immunofluorescence in the murine thymus through the use of monoclonal antibody A2B5, and specific polyclonal antisera against neurophysin (NP), oxytocin (OT) and arginine vasopressin (AVP). Two reactive regions were clearly identified: the subcapsular cortex and the medulla. A close correspondence was observed between A2B5-reactive and NP-immunoreactive cells in the medulla. An important epithelial population of the subcapsular cortex, the thymic nurse cells (TNCs), were found to be A2B5-positive and to contain immunoreactive NP, OT and AVP. The neuroendocrine nature of TNCs was further substantiated by their high reactivity with an antiserum against neuron-specific enolase. These observations demonstrate the presence in the thymus gland of an original neuroendocrine microenvironment which could be of functional importance in the mediation of central influences upon T lymphocyte differentiation.

Prolactin levels during the menstrual cycle

The levels of prolactin, FSH, LH, oestradiol and progesterone were measured daily during fourteen ovulatory cycles. The behaviour of FSH, LH, oestradiol and progesterone was classical. Non-systematic changes occurred in prolactin levels during the course of the menstrual cycle with the highest level being either during the ovulatory period or during the luteal phase. However, the mean level of prolactin was significantly higher during the ovulatory and luteal phases than during the follicular phase. A direct relationship between oestradiol and prolactin levels was noted, although there was no correlation between prolactin on the one hand and FSH, LH and progesterone on the other.

Mutation analysis of the MEN1 gene in Belgian patients with multiple endocrine neoplasia type 1 and related diseases

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by tumors in parathyroids, enteropancreatic endocrine tissues, anterior pituitary, and other tissues. The gene for MEN1 has recently been cloned and shown to code for a 610-amino acid protein of enigmatic function which probably acts as a tumor suppressor. Several mutations causing the MEN1 phenotype have been recently identified. In order to determine the spectrum of MEN1 gene mutations in a sample of 25 Belgian patients, we have systematically screened the 10 exons and adjacent sequences of the MEN1 gene by means of an automatic sequencing protocol. Twelve different mutations were identified including nonsense, frameshift, splicing, and missense mutations. Two of these mutations (D172Y and 357del4) occurred more than once. A missense mutation was also found in a kindred with familial hyperparathyroidism. We observed no significant correlation between the nature or position of mutation and the clinical status. We have also detected 6 intragenic polymorphisms and DNA sequence variants and have analyzed their frequencies in our population.

Blunted response of growth hormone to clonidine and apomorphine in endogenous depression

We measured the growth hormone (GH) response to clonidine (an alpha-2-adrenergic agonist) and to apomorphine (a dopaminergic agonist) in 15 major endogenous and 15 minor depressive in-patients matched for gender and age. Results showed a significantly smaller GH response in the major depressives to both clonidine (P less than 0.01) and apomorphine (P less than 0.001). No significant difference existed between the two groups with regard to changes in blood pressure and pulse rate during either test. While major depressives showed a trend toward smaller sedative side-effects than minor depressives after clonidine, they showed significantly smaller sedative and gastro-intestinal side-effects after apomorphine. No significant correlation was present either in the major depressive or in the minor depressive group between the GH responses following clonidine and apomorphine challenges. These results support the hypothesis of both noradrenergic and dopaminergic neurotransmitter disturbances in major depression, with individual variability with regard to those biochemical anomalies.

Dose-response relationship between plasma oxytocin and cortisol and adrenocorticotropin concentrations during oxytocin infusion in normal men

We previously demonstrated that acute injection of a pharmacological dose of oxytocin (2 IU) in humans decreased the concentrations of ACTH and cortisol, a neuroendocrine action opposite that of vasopressin. In the present work the effect of continuous infusion of lower doses of oxytocin was tested. Plasma oxytocin was also measured using an oxytocin RIA to study the dose-response relation. Infusion of oxytocin (8 mIU/min for 30 min) resulted in a plasma oxytocin level of 9.9 +/- 1.4 (+/- SD) muIU/ml and induced a decrease in the plasma concentration of ACTH in three of four normal subjects. Infusion of oxytocin at the rate of 16 mIU/ml for 30 min resulted in plasma oxytocin level of 17.7 +/- 1.6 muIU/ml and decreases in plasma ACTH and cortisol concentrations in all six subjects tested. Increasing the oxytocin dose from 32 to 64 and 128 mIU/min for three additional 30-min periods induced more pronounced decreases in plasma ACTH and cortisol. In each subject, there was a highly significant inverse relationship between plasma oxytocin, and ACTH and cortisol (r = -0.85 to -0.99). During saline infusion, a significant inverse relationship with a 10-min lag period between plasma oxytocin and ACTH (r = -0.55) was found in only one of six subjects. These data demonstrate that infusion of exogenous oxytocin leading to plasma levels approximately 10 times higher than normal induced consistent decreases in corticotropic function. Because the oxytocin concentration in portal blood is approximately 300 times higher than that in peripheral blood, it is likely that the inhibitory action of oxytocin on ACTH secretion is of physiological significance.

Concurrent use of REM latency, dexamethasone suppression, clonidine, and apomorphine tests as biological markers of endogenous depression: a pilot study

In a sample of 12 major depressive inpatients, endogenous subtype (8 primary and 4 secondary) defined by Research Diagnostic Criteria, we compared the sensitivity of four potential biological markers: latency of rapid eye movement (REM) sleep (recorded during at least 4 consecutive nights), dexamethasone suppression, and the clonidine and apomorphine tests. Shortened REM latency (less than 50 minutes during at least 1 night) identified 67% of depressives (87% of primary and 25% of secondary); nonsuppression after dexamethasone identified 50% of depressives (62% of primary and 25% of secondary); blunted growth hormone (GH) response after clonidine identified 75% of depressives (100% of primary and 25% of secondary); and blunted GH response after apomorphine identified 42% of depressives (62% of primary and 0% of secondary). Ninety-two percent of patients were correctly identified by at least one biological marker (100% of primary and 75% of secondary depressives). Of 67% of patients positive on at least two biological markers, all were primary depressives (100%). These four biological markers do not necessarily identify the same population, suggesting that their concurrent use may yield the highest level of diagnostic sensitivity.

A psycho-endocrinological overview of transsexualism

The technical possibility of surgical sex change has opened up a debate concerning the legitimacy and utility of carrying out such an intervention at the request of the transsexual. Diagnostic, psychological, medical and ethical arguments have been brought forth, both for and against. Nonetheless, anatomical transformation by surgical means has currently become a practice as the frequency of serious gender identity disorders is constantly progressing. After a brief introduction, the present paper will consider typological, aetiological and epidemiological aspects of transsexualism. Treatment of the sex change applicant is then defined and discussed in terms of psychological, psychiatric, endocrinological and surgical aspects. Finally, the question of post-operation follow-up will be examined.

Apomorphine stimulation of vasopressin- and oxytocin-neurophysins. Evidence for increased oxytocinergic and decreased vasopressinergic function in schizophrenics

Apomorphine challenge tests (0.5 mg SC) were performed in 14 normal male volunteers and in 9 male schizophrenic inpatients, drug-free for at least 2 wk. In the normal volunteers, apomorphine induced an increase of serum growth hormone (GH) (maximum at 40 min), of vasopressin-neurophysin (hNpI) (maximum at 20 min), and oxytocin-neurophysin (hNpII) (maximum at 20 min). The release of neurophysins was independent of digestive side effects. In the schizophrenics, the GH level and release pattern were similar to those in the controls. The basal level of hNpI was reduced (t0: 0.42 +/- 0.1 ng/ml in the schizophrenics and 0.66 +/- 0.05 ng/ml in the controls, p < 0.02). In contrast, the basal level of hNpII was increased (3.34 +/- 0.04 ng/ml in the schizophrenics to 0.92 +/- 0.21 ng/ml in the controls, p = 0.001). The response to apomorphine was blunted, with no significant release of hNpI or of hNpII. Although the hNpII data are consistent with an increased dopaminergic tone, the psychopathological meaning of the increased basal oxytocinergic and decreased vasopressinergic functions remains to be defined.