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Biomedical subjects

F Laczi

Publications and source records attributed to F Laczi.

At least 55 records · Page 3Linked to original sources
PubMed1983

[The effect of vasopressin analogs on water metabolism].

The effects of naturally occurring lysine and arginine vasopressins (LVP and AVP) were compared with those of 1-deamino-8-D-arginine-vasopressin (dDAVP) and 1-deamino-4-valine-D-arginine-vasopressin (dVDAVP). The changes of minute diuresis, urinary osmolarity and the duration of action were followed. dDAVP and dVDAVP in a single intravenous and intranasal dose decreased the diuresis more markedly (3.5-fold) and for a longer duration (3.3-fold) than did LVP in patients with central diabetes insipidus. The administration of dDAVP and dVDAVP in the form of sublingual tablets also proved to be effective, where dVDAVP acted more markedly and longer (16 hrs) than dDAVP (12 hrs) in a single dose of 30 micrograms. During one week of sublingual dDAVP administration, the accumulation of the drug was indicated by the gradual decrease of diuresis and the increase of urine osmolarity. The misuse of such highly active drugs may even result in iatrogenic inappropriate ADH syndrome (Schwartz-Bartter). The danger of this syndrome will be demonstrated in a case history. Some more recently synthesized vasopressin analogues with antagonistic action on the diuresis may have an important role in the therapy of Schwartz-Bartter syndrome. The authors present their results with one of these antagonists [1-(beta-mercapto-beta, beta-cyclopentamethylene-propionic acid), 2-O-ethyltyrosine, 4-valine] arginine vasopressin (d/CH2/5Tyr/Et/VAVP) both in Brattleboro and in R-Amsterdam rats. This analogue blocks the antidiuretic effect of both exogenous and endogenous vasopressin.

Animals↗
PubMed1983

Differential responses in immunoreactive arginine-vasopressin content of microdissected brain regions during passive avoidance behavior.

Immunoreactive arginine-vasopressin (IR-AVP) was measured in various hypothalamic and extrahypothalamic nuclei of male Wistar rats immediately after the 24 h retention test of a passive avoidance response. IR-AVP concentrations in paraventricular, suprachiasmatic and lateral septal nuclei were significantly decreased in comparison with the non-shocked rats, while IR-AVP was increased in the central amygdala nucleus, subfornical organ and locus coeruleus. No significant differences in IR-AVP levels were found in the habenular and periventricular hypothalamic nucleus, organum vasculosum of lamina terminalis and medial and dorsal raphe nucleus.

Animals↗
PubMed1983

Vasopressin and oxytocin content in cerebrospinal fluid and in various brain areas after administration of histamine and pentylenetetrazol.

The content of vasopressin (AVP) and oxytocin (OXT) in the septum, hippocampus, hypothalamus and cortex was determined at 5 min and 24 hr after peripheral (intraperitoneal) administration of histamine (20.0 mg/kg) and pentylenetetrazol (45.0 mg/kg) and in the cerebrospinal fluid at 24 hr after pentylenetetrazol treatment. At 5 min after administration of histamine the AVP content in the septum was increased whereas the OXT level in the various areas was not changed. At 24 hr, neurohypophyseal peptide contents were unaffected in the brain regions analyzed. Pentylenetetrazol did not alter AVP content at 5 min after its administration, however, the OXT level in the septum and the cortex was diminished. At 24 hr after administration of pentylenetetrazol a decreased AVP content in the hippocampus and in the cortex was observed. In contrast, OXT content in the cortex was increased at this time. AVP and OXT levels in CSF were not changed at 24 hr following pentylenetetrazol treatment. The present results suggest that the levels of neurohypophyseal hormones can be differentially altered in particular brain regions at short- (5 min) and long- (24 hr) term intervals after treatment with histamine or pentylenetetrazol. Long-term changes in AVP and OXT levels after pentylenetetrazol may be implicated in the amnesic properties of this convulsive drug. Furthermore, the present findings point to a possible relationship with previously reported pentylenetetrazol-induced changes in peptide levels in the CSF.

Animals↗
PubMed1983

Effects of desglycinamide-arginine-vasopressin (DG-AVP) on memory processes in diabetes insipidus patients and non-diabetic subjects.

The effects of desglycinamide9-arginine8-vasopressin (DG-AVP) on memory processes have been studied in patients with central diabetes insipidus (DI) and in non-diabetic control patients. Acute im injection of DG-AVP improved some aspects of short-term memory. Subchronic intranasal administration of DG-AVP facilitated short-term memory more consistently and in addition improved long-term memory. DG-AVP increased the attention, but only in the non-diabetic subjects. The effects of DG-AVP on memory processes persisted after discontinuation of treatment. DG-AVP did not affect the parameters for water and electrolyte metabolism, blood pressure and pulse rate neither in DI nor in the control patients. Thus, the memory effects of DG-AVP are probably mediated by a direct action on the central nervous system.

Adolescent↗
PubMed1983

Lack of effect of desglycinamide-arginine-vasopressin (DGAVP) on memory in patients with korsakoff's syndrome.

The effect of desglycinamide9-[Arg8]-vasopressin (DGAVP) on memory processes was studied in patients with Korsakoff's syndrome. Intranasal treatment with DGAVP for 7 days affected neither attention nor short- and long-term memories. It is suggested that treatment with DGAVP is not indicated for all types of memory disorders, and that the beneficial effect of this treatment may depend on the integrity of certain brain structures.

Aged↗
PubMed1982

Effects of lysine-vasopressin and 1-deamino-8-D-arginine-vasopressin on memory in healthy individuals and diabetes insipidus patients.

Central diabetes insipidus (DI) patients showed impairments in short- and long-term memory functions, but not in attention and concentration, as compared to healthy individuals. A single i.m. injection or sub-chronic intranasal administration of either lysine-vasopressin (LVP) or 1-deamino-8-D-arginine-vasopressin (DDAVP) normalized the disturbed memory functions in DI patients. These peptides also improved memory functions in healthy individuals.

Administration, Intranasal↗
PubMed1982

Biological half-lives and organ distribution of tritiated 8-lysine-vasopressin and 1-deamino-8-D-arginine-vasopressin in Brattleboro rats.

The biological half-lives and organ distribution of tritiated 8-lysine-vasopressin and 1-deamino-8-D-arginine-vasopressin were determined in R-Amsterdam rats and in homozygous and heterozygous Brattleboro rats with hereditary central diabetes insipidus. It was found that the biological half-lives of [3H]LVP and [3H]dDAVP in the Brattleboro rats did not differ significantly from that found in the control R-Amsterdam rats. The half-life of [3H]dDAVP proved longer than that of [3H]LVP in all three groups of animals. In the case of [3H]LVP the highest radioactivities were observed in the neurohypophyses, adenohypophyses, and kidneys of both the R-Amsterdam and Brattleboro rats. The accumulation of tritiated material was higher in the small intestine of the Brattleboro rats than in that of the R-Amsterdam animals. In all three groups of rats, [3H]dDAVP was accumulated to the greatest extent in the kidney and the small intestine. The kidney and small intestine contained less radioactivity in homozygous Brattleboro rats than in the controls. There was only a slight radioactivity accumulation in the adenohypophysis and neurohypophysis. From the results it was concluded that the decrease in the rate of enzymatic decomposition may play a role in the increased duration of antidiuretic action of dDAVP. The results have led to the conclusion that the accelerated elimination of vasopressin and its pathologic organ accumulation are probably not involved in the water metabolism disturbance of Brattleboro rats with hereditary diabetes insipidus.

Animals↗
PubMed1982

Serum FSH and LH levels in men after administration of a long-acting LH-RH preparation.

The effects of the natural gonadotropin releasing hormone (LH-RH) and of a long-acting analogue, desgly10-D-leu6-LH-RH ethylamide, on the serum FSH, LH, testosterone and oestradiol-17 beta levels were studied in healthy men. The basal value for FSH was 3.58 +/- 0.47 mU/ml (SE), for LH 6.33 +/- 1.19 mU/ml. Following an intravenous dose of LH-RH the values increased by 3.40 +/- 0.88 and 25.99 +/- 5.67 mU/ml, respectively. After intravenous administration of the long-acting analogue, the peak FSH exceeded the basal value by 12.89 +/- 6.95 mU/ml, while LH increased by 41.27 +/- 4.72 mU/ml. The effect of the analogue on FSH and LH lasted 693 min and 862 min, respectively. Neither preparation changed the serum testosterone or oestradiol-17 beta levels essentially. The results suggest that the long-acting variant of LH-RH is more suitable than the natural hormone for examination of the FSH and LH reserves in men.

Adolescent↗
PubMed1981

Effects of vasopressin analogues (DDAVP, DVDAVP) in the form of sublingual tablets in central diabetes insipidus.

The effects of 1-deamino-8-D-arginine vasopressin (DDAVP), 1-deamino-4-valin-8-D-arginine vasopressin (DVDAVP) and 8-arginine vasopressin (AVP) on water metabolism have been examined in 18 patients suffering from central diabetes insipidus. The hormone derivatives were sublingually administered. It was established that DDAVP and DVDAVP significantly reduced diuresis and increased urine osmolarity. DVDAVP was found to be more effective than DDAVP. AVP administered in equal doses had no significant effect on water metabolism. The duration of the action of sublingually administered DDAVP was 12 hrs; after dosing DVDAVP the effect lasted even 6 hrs. During one week of DDAVP administration, the accumulation of the drug was indicated by the gradual decrease of diuresis and the increase of the urine osmolarity. The sublingual administration of both DDAVP and DVDAVP tablets (3 X 30 micrograms/day) had an adequate therapeutic effect.

Adult↗
PubMed1980

Effects of somatostatin and bromocryptine on the plasma ACTH level in bilaterally adrenalectomized patients with Cushing's disease.

The effects of somatostatin and bromocryptine were examined in patients bilaterally adrenalectomized because of Cushing's disease, in one of whom Nelson's syndrome had developed. Following a 250 microgram (152 nmol) somatostatin bolus, administered i.v., a further 250 microgram *152 nmol) somatostatin was given by infusion over 90 minutes. In all patients the high basal value of the serum ACTH was considerably decreased 60 minutes after the bolus, but after 240 minutes the basic value was almost restored. In the patients without Nelson's syndrome the plasma ACTH decreasing action of oral 2.5 mg (3.38 mumol) bromocryptine exceeded 300 minutes. In the Nelson's syndrome patient the early ACTH-decreasing effect of bromocryptine was greater, but after 300 minutes the ACTH level had risen to nearly twice the basic value.

Adrenal Cortex↗
PubMed1980

Study on the biological half-life and organ-distribution of tritiated lysine-vasopressin in Brattleboro rats.

The biological half-life and organ-distribution of triated lysine-vasopressin were determined in R-Amsterdam rats, and in homozygous and heterozygous Braddleboro rats with hereditary central diabetes insipidus. It was found that the biological half-life of the tritiated lysin-vasopressin in the Brattleboro rats did not differ significantly from that found in the R-Amsterdam rats. The highest radioactivities were observed in the neuro- and adenohypophyses and in the kidneys of both the R-Amsterdam and the Brattleboro rats. The accumulation of tritiated LVP was higher in the small intestine of the Brattleboro rats than in that of the R-Amsterdam animals. The results have led to the conclusion that the accelerated elimination of vasopressin and its pathologic organ-accumulation are probably not involved in the water metabolism disturbance of Brattleboro rats with hereditary hypothalamic diabetes insipidus.

Animals↗