atrial-natriuretic-factor and Schizophrenia

We studied the effects of a short-term hypertonic stimulus on plasma levels of the stress hormones adrenocorticotropin (ACTH), cortisol, prolactin, and the blood volume- and electrolyte-controlling hormones arginine vasopressin (AVP) and atrial natriuretic peptide (ANP). Seven patients suffering from chronic schizophrenia with negative symptoms and ten healthy control subjects were investigated by a 20-minute infusion of 10 ml/kg body weight of hypertonic (2.5%) versus isotonic (0.9%) saline. All patients, who were medication-free for at least one week prior to the study, and all control subjects participated in two investigations in randomized order according to a single-blind cross-over design. During hypertonic infusion, plasma osmolarity and sodium levels were increased similarly in both groups and significantly more than during isotonic saline. Hypertonic saline caused a significant increase of plasma ACTH, cortisol and prolactin in patients in contrast to controls. AVP and ANP plasma concentrations were elevated after infusion of hypertonic saline, however, only patients showed a significant rise in plasma ANP. These results show that a dysregulation of the hypothalamic-pituitary-adrenal (HPA) system in a subset of patients with chronic schizophrenia may become overt during an osmotic stimulation, indicating an increased sensitivity of patients with schizophrenia to osmotic stress.

Topics: Adrenocorticotropic Hormone; Adult; Arginine Vasopressin; Atrial Natriuretic Factor; Chronic Disease; Cross-Over Studies; Female; Humans; Hydrocortisone; Infusions, Intravenous; Isotonic Solutions; Male; Osmotic Pressure; Prolactin; Saline Solution, Hypertonic; Schizophrenia; Single-Blind Method; Time Factors

Respective contributions of arginine vasopressin (AVP) and atrial natriuretic peptide (ANP) to the urinary sodium concentration were evaluated in 23 naturalistic incidents of polydipsia-hyponatremia observed in 11 hospitalized schizophrenics (10 males and 1 female). The sodium concentration of the spontaneously excreted urine was examined before and after the forced water restriction. Before the water restriction, mean (+/-S.D.) plasma ANP was 52.8 +/- 33.9 pg/ml (range = 6.9-137). Plasma AVP levels were below 0.3 pg/ml in 15 episodes; relatively high levels (> or = 0.3) were noted in eight episodes. Means of urinary sodium concentration (mEq/l) were significantly higher in episodes with high AVP (> or = 0.3) alone (25.0 +/- 8.2, n=4), with high ANP (> 43) alone (21.3+/-7.4, n = 9), and with high AVP and ANP (26.8 +/- 6.4, n = 4) as compared to that of the low AVP (< 0.3) and ANP (< or = 43) group (13.5 +/- 3.7, n = 6). The data indicate that the elevated urinary sodium in polydipsic patients is possibly due to the AVP-induced antidiuresis and/or the ANP-induced natriuresis. In addition, we observed a close relationship between elevated plasma AVP and vomiting, suggesting that vomiting is one of the causal factors responsible for AVP elevations in this syndrome.

Topics: Adult; Arginine Vasopressin; Atrial Natriuretic Factor; Female; Humans; Hyponatremia; Male; Middle Aged; Schizophrenia; Thirst

Chronic schizophrenic patients are reported to develop imbalanced water homeostasis by the pathological secretion of vasopressin and aldosterone. We measured plasma vasopressin, aldosterone and atrial natriuretic peptide in schizophrenic patients to elucidate the role of these hormones during a perioperative period. Eighteen schizophrenic patients with chronic antipsychotic drugs over 10 years and 22 as a control group who underwent elective lower abdominal surgery were the subjects of this study. In the schizophrenic patients, plasma aldosterone secretion was significantly inhibited, while plasma vasopressin and atrial natriuretic peptide were significantly increased during surgery. A good relationship (r = 0.69, p < 0.01) between plasma atrial natriuretic peptide and plasma osmolality was obtained 60 min after skin incision, but not before the induction of anesthesia. The findings suggest that chronic schizophrenic patients may develop an abnormal secretion of vasopressin, aldosterone and atrial natriuretic peptide during anesthesia.

Topics: Adult; Aged; Aldosterone; Atrial Natriuretic Factor; Case-Control Studies; Chronic Disease; Dopamine; Female; Humans; Intraoperative Period; Linear Models; Male; Middle Aged; Osmolar Concentration; Prospective Studies; Schizophrenia; Time Factors; Vasopressins; Water-Electrolyte Imbalance

Polydipsia-hyponatremia is a poorly understood disorder that causes considerable mortality and morbidity. Hyponatremia in polydipsia-hyponatremia has been attributed to disturbances in antidiuretic hormone (ADH) function. Improvements in polydipsia-hyponatremia during clozapine treatment offered the chance to see if levels of ADH and other hormones associated with osmoregulation changed with improvement in biochemical and clinical measures of polydipsia-hyponatremia.. In this preliminary, longitudinal study, we studied 2 male schizophrenic patients (DSM-III-R) who had polydipsia-hyponatremia. Measures were (1) biochemical and clinical: serum sodium and osmolality, urine osmolality and specific gravity, normalized diurnal weight gain, and estimated urine volume and (2) endocrine: ADH, angiotensin II, atrial natriuretic peptide, and prolactin. Measures were collected during 2 months of baseline (typical neuroleptic) and 6 months of clozapine treatment.. Single-case statistical procedures showed significant changes in sodium levels (a.m. and p.m.), estimated urine volume, and a.m. urine specific gravity in both patients and significantly decreased diurnal weight gain in 1 patient. Both serum and urine osmolality showed improvement, but values did not reach statistical significance. Low baseline ADH levels persisted through 6 months of clozapine treatment and showed no changes in the context of improvements in serum sodium and osmolality. No significant changes were seen in levels of angiotensin II and atrial natriuretic peptide.. Given the limitations of this study, there is some evidence to suggest that the improvements in serum sodium and osmolality during clozapine treatment of polydipsia-hyponatremia may not be related to serum levels of ADH, although altered ADH receptor function cannot be ruled out. These data need to be extended in larger samples.

Topics: Adult; Angiotensin II; Atrial Natriuretic Factor; Circadian Rhythm; Clozapine; Humans; Hyponatremia; Longitudinal Studies; Male; Middle Aged; Osmolar Concentration; Prolactin; Schizophrenia; Sodium; Urine; Vasopressins; Water Intoxication

Plasma levels of arginine vasopressin (AVP) and atrial natriuretic peptide (ANP) were measured in 15 patients with schizophrenic or schizoaffective disorders and 15 healthy volunteers during oral water loading at 20 ml/kg. In the patient group, plasma AVP was secreted even when plasma osmolality was below 270 mosmol/kg, although the sensitivity of AVP secretion response to osmolality was lower than in the controls. The ANP level was higher in the group of patients than in the controls. There was a negative correlation between plasma ANP and osmolality in the patients. We speculate that the volume expansion caused by inappropriate AVP secretion stimulated plasma ANP release and that the natriuresis resulting from the elevated plasma ANP level might contribute to hyponatremia.

Topics: Adult; Arginine Vasopressin; Atrial Natriuretic Factor; Blood; Female; Humans; Hyponatremia; Inappropriate ADH Syndrome; Male; Middle Aged; Osmolar Concentration; Psychiatric Status Rating Scales; Radioimmunoassay; Schizophrenia; Sodium

Topics: Acetates; Atrial Natriuretic Factor; Central Nervous System Stimulants; Meclofenoxate; Psychiatry; Schizophrenia