[Etiology, diagnostics and therapy of hyponatremias].

Etiopathogenesis, diagnostics and therapy of hyponatremias are summarized for clinicians. Hyponatremia is the most common electrolyte abnormality. Mild to moderate hyponatremia and severe hyponatremia are found in 15-30% and 1-4% of hospitalized patients, respectively.

[Diabetes insipidus: etiology, diagnosis, and therapy].

Diabetes insipidus is a disorder of the water retaining ability of the organism. It is a polydipsic-polyuric syndrome caused by partial or complete vasopressin deficiency (central diabetes insipidus) or vasopressin resistance of the kidney tubules (nephrogenic diabetes insipidus) or increased water intake due to oversensitivity of the thirst centre (dipsogenic diabetes insipidus = primary polydipsia). The pathogenetic factors may affect the osmoreceptors, the vasopressinergic magnocellular nuclei of the hypothalamus, the median eminence, the pituitary stalk, the vasopressin release from the neurohypophysis, the vasopressin inactivating mechanisms and the renal structures mediating the antidiuretic effect of vasopressin.

[Current alternative in the pharmacotherapy of acromegaly: the long-acting somatostatin analogue octreotide].

Twelve active acromegalic patients (10 women, 2 men) were chronically treated with a long-acting microcapsulated preparation of octreotide (Sandostatin LAR, Novartis). In each case, a growth hormone-producing pituitary adenoma was responsible for the development of acromegaly (microadenomas in 3 and macroadenomas in the rest of the patients). Treatment with long-acting octreotide was indicated for those patients who had not reacted satisfactorily upon previous therapeutic procedures or proved to be unsuitable for irradiation therapy and/or surgery or refused both of these therapies.

Octreotide-induced drinking, vasopressin, and pressure responses: role of central angiotensin and ACh.

The involvement of central angiotensinergic and cholinergic mechanisms in the effects of the intracerebroventricularly injected somatostatin analog octreotide (Oct) on drinking, blood pressure, and vasopressin secretion in the rat was investigated. Intracerebroventricular Oct elicited prompt drinking lasting for 10 min. Water consumption depended on the dose of Oct (0.

[Current diagnostic method, prognosis estimation and therapy of papillary thyroid cancer: recommendations of the medical universities and the National Oncologic Institute of Budapest].

Physical examination, cervical ultrasonography (US) and aspiration cytology are the mainstays of the preoperative diagnostics of papillary thyroid carcinoma. For the staging of suspected malignant cases, cervical and mediastinal CT (MRI for inconclusive results) is indicated before any surgery. The end-result of primary treatment is assessed by total-body iodine scintigraphy and the serum human thyroglobulin (hTG) level.

[Effect of somatostatin-octreotide on secretion of adrenocorticotropin, cortisol and neuro-hypophyseal hormones in acromegaly].

The present work was aimed at studying the combined effects of somatostatin and corticotropin releasing hormone on the activities of the pituitary-adrenocortical axis and neurohypophysis. Patients with active acromegaly were intravenously injected with a 100 micrograms human corticotropin releasing hormone bolus before and after a 3-month subcutaneous treatment with somatostatin-octreotide (SMS 201 995; Sandostatin; 200 micrograms t. i.

Neurohypophysial hormone secretion in hyperprolactinaemic women.

Prolactin (PRL) has been reported to promote antidiuresis and increase intestinal water-electrolyte absorption, whereas osmolar changes have been shown to influence PRL secretion. However, the mechanisms of action of PRL on the salt-water balance remain unclarified. The present clinical study targeted the effects of hyperprolactinaemia on the secretion of arginine-8-vasopressin (AVP), oxytocin (OXT) and cortisol.

Changes in rat sleep after single and repeated injections of the long-acting somatostatin analog octreotide.

Somnogenic activity is attributed to both growth hormone (GH) and GH-releasing hormone (GHRH). The aim of our experiments was to study sleep after suppression of the somatotropic axis by means of administration of a long-lasting somatostatin analog, octreotide. Rats received subcutaneous injections of physiological saline (baseline), octreotide (1, 10, and 200 microg/kg), or a control solution just before light onset, and sleep-wake activity and cortical brain temperature were recorded for 23 h.

[Repeated serious water intoxication in an aged patient. (Data on the relationship between the inappropriate antidiuretic hormone syndrome and the atrial natriuretic factor)].

An old women was in an 8-year-period 9 times admitted to the hospital because of severe mental disturbances. The average serum sodium concentration was 126.25 +/- 2.

Specific radioimmunoassay of oxytocin in rat plasma.

Sensitive, specific and reproducible radioimmunoassay (RIA) was developed for the measurement of oxytocin (OXT) in rat blood plasma after various extraction methods. The assay is based on an antiserum raised against OXT in rabbit. The sensitivity, affinity constant, and cross-reactivity of the antiserum were determined.

The role of central corticoliberin in the hyperosmosis-induced secretion of neurohypophysial hormones and corticosterone in the rat.

Although synthetic corticotropin-releasing hormone (CRH) is known to influence the secretion of the neurohypophysial hormones, the role of endogenous CRH in the rat brain is still unclear in this respect. Accordingly, experiments were scheduled to study the effects of intracerebroventricularly (i.c.

The role of central corticoliberin in the ether stress-induced secretion of neurohypophyseal hormones and corticosterone in the rat.

As corticotropin-releasing factor (CRF) and oxytocin (OXT) are released in response to various stressors and a role of CRF in stress-induced OXT secretion has been proposed by previous authors, the present experiments were scheduled to investigate the participation of the brain CRF system in the stress-evoked release of OXT, arginine-8-vasopressin (AVP) and corticosterone. CRF-antiserum (AS) was given into the lateral ventricle of the brain of Wistar male rats, and 24 h later, the injection was repeated 30 min prior to ether stress followed by decapitation in 5 min. Plasma OXT and AVP were measured by radioimmunoassay and corticosterone by fluorimetry.

Pharmacokinetics of DGAVP in plasma following intranasal and oral administration to healthy subjects.

A pharmacokinetic study was carried out to assess the bioavailability of desglycinamide-[Arg8]vasopressin (DGAVP, Org 5667). DGAVP (2 mg) was administered both intranasally and orally to healthy subjects with a treatment interval of 1 week. Blood samples were taken regularly between 15 min before and 210 min after administration and were assayed for DGAVP by radioimmunoassay.

Effects of cocaine on the contents of neurohypophyseal hormones in the plasma and in different brain structures in rats.

The effects of acute and chronic cocaine treatments on the levels of the neurohypophyseal hormones oxytocin (OXT) and vasopressin (AVP) in the plasma and in different brain structures in rats were measured by radioimmunoassay (RIA). Acute cocaine treatment had no effect on the level of OXT in the plasma or in the amygdala, but increased OXT contents were measured in the hypothalamus and in the hippocampus. The OXT levels in the basal forebrain structures (including the septum and the nucleus accumbens) were decreased by a single dose of cocaine.

Oxytocin modulates behavioural adaptation to repeated treatment with cocaine in rats.

Behavioural adaptation to and the effects of the neurohypophyseal peptide, oxytocin, on repeated treatment with cocaine were investigated in rats. The content of immunoreactive oxytocin in the plasma, hypothalamus and different limbic structures in the brain were also studied after treatment with cocaine, identical to that used in the behavioural experiment. Repeated administration of cocaine (7.

Two families with hereditary diabetes insipidus not due to osmoreceptor failure.

Two families with hereditary central diabetes insipidus (CDI) are reported. The pedigree in both families shows an autosomal dominant trait. The plasma arginine-8-vasopressin (AVP) determined by radioimmunoassay was markedly lower in these CDI patients than in healthy controls; the difference being even more pronounced after a hyperosmotic challenge.

Chromatographically identified oxytocin in the human peripheral nervous system.

Immunoreactive oxytocin (OXT) detected in extracts of human coeliac ganglia and nn. vagi was characterized by high-performance liquid chromatography (HPLC). HPLC/RIA examinations demonstrated that a major part of the immunoreactive material in both investigated areas co-eluted with a reference synthetic OXT, but in the extracts of coeliac ganglia a second immunoreactive peak was also observed.

Effect of vasopressin antagonist d(CH2)5Tyr(Et)VAVP on plasma arginine vasopressin level after osmotic stimulus.

The effect of the vasopressin antagonist d(CH2)5Tyr(Et)VAVP on the immunoreactive arginine vasopressin (AVP) level in plasma was studied in rats after osmotic stimulus. The blood samples were obtained from the eye plexus. An increased AVP level (193.

Central effects of antiserum against human atrial natriuretic polypeptide on water and electrolyte metabolism and plasma arginine-8-vasopressin level in conscious rats.

Although synthetic atrial natriuretic polypeptide (ANP) is known to influence the water and electrolyte metabolism and arginine-8-vasopressin (AVP) secretion, the physiological role of endogenous ANP in the rat brain is still unclear. Accordingly, an investigation was made of the effects of intracerebroventricular (icv) administration of human h-ANP antiserum, which can neutralize endogenous ANP, on the water intake, urine output, urinary excretion of potassium and sodium, and plasma AVP level in normally hydrated rats. Apart from the water intake, all the parameters were also determined in 48-h water-deprived rats after h-ANP antiserum treatment.

Vasopressin(1-8) (des-glycinamide9-[Arg8]vasopressin) is an endogenous peptide present in rat plasma.

Using a radioimmunoassay for [Arg8]vasopressin(1-8) (des-glycinamide9-[Arg8]vasopressin; DGAVP) endogenous immunoreactive DGAVP (IR-DGAVP) was detected in extracts of plasma prepared from trunk blood of male Wistar rats. The IR-DGAVP was further characterized by reversed-phase high pressure liquid chromatography (HPLC). One of the two immunoreactive peaks obtained by HPLC coeluted with synthetic DGAVP and did not cross-react in a radioimmunoassay specific for [Arg8]vasopressin(1-9) (AVP).

Characterization of oxytocin immunoreactivity in human sympathetic paravertebral ganglia.

Immunoreactive oxytocin (IR-OXT) detected in extracts of human lumbar sympathetic paravertebral ganglia was characterized by high-performance liquid chromatography (HPLC). The immunoreactive substance was found to elute at the same position as the reference preparation of oxytocin (OXT). The results revealed the presence of chromatographically identified OXT in human sympathetic ganglia.

[Regulation of vasopressin release in primary hypothyroidism and Addison's disease as well as in central diabetes insipidus].

The osmoregulation of arginine-8-vasopressin (AVP) was investigated in 14 patients with primary hypothyroidism, in 6 with Addison's disease, and in 21 with central diabetes insipidus (CDI). In the latter disease the effect of histamine stimulus was also evaluated. Plasma AVP was measured by radioimmunoassay (RIA).

Humoral changes in shock induced by cardiac tamponade.

Cardiac tamponade was induced in dogs by the infusion of saline into the pericardial cavity. The mean arterial pressure dropped to approximately one-third and the cardiac output to one-fourth of the control level. This was accompanied by the release of vasoactive humoral mediators.