Biomedical subjects

F Dajas

Publications and source records attributed to F Dajas.

45 records · Page 3Linked to original sources

PubMed1986

Evidences of a sympatho-adrenal dysfunction after lesion of the central noradrenergic pathways in rats.

The urinary excretion rates of noradrenaline and adrenaline--as an index of sympatho-adrenal activity--were assessed in a group of rats previously treated with the noradrenergic toxic agent DSP-4. The suppressive effects of clonidine (10 micrograms/kg) on urinary NA excretion were also evaluated. Basal noradrenaline and adrenaline excretion rates were higher in DSP-4 treated rats than in controls. Clonidine elicited a marked suppression of urinary noradrenaline excretion rates in control rats but not in those treated with DSP-4 90-120 days before. Endogenous catecholamine level determinations, 120 days after DSP-4 administration, evidenced, on the one hand, an almost complete depletion of noradrenaline levels in spinal cord, cerebral cortex, and hippocampus. On the other hand, a significant increase of noradrenaline in the kidney and of adrenaline in the adrenal gland was found. These results are interpreted as indicating that the lesion of central noradrenergic pathways induces a sympatho-adrenal hyperactivity as well as an impaired response to alpha-2 adrenergic receptor agonists.

Adrenal Medulla↗

PubMed1986

Urinary norepinephrine excretion in panic and phobic disorders.

Morning urinary norepinephrine (NE) was assessed in 36 patients suffering from panic and phobic disorders according to DSM III. Urinary NE excretion was significantly higher in this group than in a normal control one. Phobic patients excreted lower levels of NE than panic ones. No significant association was found between urinary NE levels and anxiety scores according to Zung's Anxiety Status Inventory or Wittenborn Psychiatric Rating Scale. The NE increase is interpreted as reflecting a sympathetic nervous system hyperactivity in anxiety. A concomitant effect upon NE metabolism of benzodiazepine withdrawal cannot be discarded since the group of patients previously medicated showed the highest NE excretion.

Adolescent↗

PubMed1984

High urinary norepinephrine excretion in major depressive disorders: effects of a new type of MAO inhibitor (Moclobemide, RO 11-1163).

The urinary excretion rates of norepinephrine were assayed in 26 patients diagnosed as major depressive disorders (primary, unipolar), before and after 14 days of treatment with the monoamine oxidase inhibitor Moclobemide (Ro 11-1163). A standardized 1-h urine collection procedure was used and norepinephrine was assayed by liquid chromatography with electrochemical detection. Norepinephrine was found significantly increased in depressed patients when compared with a control population. The psychotic patients showed the highest excretion rates although they were not significantly different from the endogenous (non-psychotic) group. Urinary norepinephrine output significantly decreased after 14 days of treatment with Moclobemide. This decrease was also marked in those patients that did not show any therapeutic effect. A clear antidepressant effect, shown by a significant decrease of the Hamilton Scale scores for depression, was apparent as early as the 7th day. Increased norepinephrine in melancholic patients was taken as a presumptive indication of altered sympathetic activity.

Adult↗

PubMed1984

Resting urinary catecholamine excretion in schizophrenics: methodology and interpretation of results.

Plasma and urinary catecholamines were measured in a group of schizophrenics and in normal subjects by high performance liquid chromatography with electrochemical detection. A brief procedure for urine sampling performed under standardized environmental and physical conditions was used. Plasma levels and urinary excretion rates of noradrenaline were significantly higher in schizophrenics than in a control population. When plotted for linear regression analysis, both plasma and urinary noradrenaline values were positively correlated (r = 0.75, p less than 0.05). Results reported suggest that urinary catecholamine measurement could be used for a reliable assessment of sympatho-adrenal function in schizophrenia.

Adult↗

PubMed1983

Effects of intraventricular curarimimetics on hippocampal electrical activity.

The effects on the hippocampal electroencephalogram (EEG) of intraventricular injections of the nicotinic ligand alpha-Naja naja toxin, and of d-tubocurarine, were studied in rats immobilized with gallamine or anesthetized with urethane. The EEG recordings were taped and processed off-line to calculate power spectra, autocorrelation functions, and averages. In addition, the times at which spike-and-wave complexes appeared were identified and autocorrelation histograms and cross correlations (with the EEG) were made. Naja toxin and d-tubocurarine provoked a 3.5- to 5-Hz theta rhythm in both hippocampi. Higher doses elicited rhythmic epileptic spike and wave complexes which appeared at a preferred phase of theta rhythm. Atropine and medial septal lesions blocked the rhythm and disrupted the rhythmicity of epileptiform activity. We conclude that different neural subsystems sustain the theta rhythm and epileptiform spikes, and discuss the possible mechanisms involved.

Animals↗

PubMed1983

Plasma noradrenaline and clinical psychopathology in schizophrenia. A correlation analysis.

Plasma noradrenaline was assayed in schizophrenics selected according to research diagnostic criteria. Clinical symptomatology was simultaneously rated according to the comprehensive psychopathological rating scale. Global psychopathology, positive (delusional, hallucinatory), negative (autistic), paranoid and hallucinatory symptomatology were separately rated. Noradrenaline was significantly higher in schizophrenics than in a normal control group. A correlation analysis was applied to both psychopathology and plasmatic noradrenaline levels. Noradrenaline was significantly correlated (p less than 0.05 to p less than 0.02) with global psychopathology, positive symptoms and paranoid symptomatology. No correlation was demonstrated between plasma noradrenaline and negative and hallucinatory symptomatology. Plasma noradrenaline is proposed to be related to a high level of sympathetic general activity in schizophrenics, specially associated with paranoid symptomatology.

Adult↗

PubMed1979

Microdensitometry of acetylcholinesterase in subfields of the hippocampal pyramidal layer and fascia dentata.

A quantitative acetylcholinesterase enzyme-histochemical study was performed with microdensitometric methods in the hippocampus of the rat in order to correlate this enzymatic activity with the different zones of the hippocampal pyramidal layer. Higher values of acetylcholinesterase activity were found in the CA3 pyramidal zone. CA1 and CA4 showed the same activity, while the stratum oriens at CA3 showed the highest values among the hippocampal layers studied. The results were correlated with differences in septal afferences.

Acetylcholinesterase↗

PubMed1978

Enzyme histochemistry of the rat hippocampus during experimental status epilepticus.

EEG registered hippocampal status epilepticus (HSE) was provoked in 41 adult albino rats by intraseptal injection of ouabain, and the hippocampus was studied from 1 1/2 to 24 hr with the enzyme histochemical tests for succinic dehydrogenase (SDH), lactic dehydrogenase (LDH), thiaminopyrophosphatase (TPPase), acid phosphatase (AcPase), Mg2+ adenosine triphosphatase (Mg2++ ATPase), and with general and neurohistological stains. In a first group of animals (1 1/2 to 10 hr of HSE), a stage of general increase in enzymatic activity was detected in the pyramidal neurons (SDH, LDH, AcPase, and TPPase). Mg2+ ATPase showed a marked increase in astrocytes. In a second group (more than 10 hr of HSE), SDH was found decreased in the dendritic fields. LDH activity persisted in neuronal bodies, and AcPase and TPPase showed diffuse activity in the cytoplasm of some pyramidal neurons. In a third group (more than 18 hr of HSE), SDH activity was low. No AcPase granules were observed in some pyramidal neurons and TPPase was negative in some areas of pyramidal layer. Mg2+ ATPase reaction showed scare and retracted astroglial processes. These changes were coincident with "cellular ghosts" observed with hematoxylin-eosin techniques of the same samples in the pyramidal field and were interpreted as cellular death, attributed to relative anoxia following neuronal discharge.

Acid Phosphatase↗

PubMed1976

Enzyme histochemistry of rat interfascicular oligodendroglia, with special reference to 5'-nucleotidase.

The interfascicular oligodendroglia of the rat striatum nucleus is studied in control animals and under experimentally induced brain edemas. Enzyme histochemical studies were performed. Normal oligodendrocytes show two different enzymatic distributions. While Mg2+-ATPase, TPPase, TPPase, adenylate cyclase and SDH are shown to be situated at the cell bodies and some proximal processes, 5'-nucleotidase reaction is seen at the cell fine distal processes. In spite of its trong activity in oligodendroglial endings the latter enzyme is not seen at the myelin sheath. This sheath and the interfascicular cells being intimately related, 5'-nucleotidase appears to be important not only during myelination, as almost all authors emphasize, but also in the adult myelin metabolism. Experimental brain edema shows some changes in the interfasicular oligodendroglia enzymatic activites for 5'-nucleotidase, Mg2+-ATPase and adenylate cyclase. A progressive disappearance of the former enzyme is observed. These features and those of derived from local ionic alterations may be concerned with the special susceptibility of white matter for some types of brain swellings.

Animals↗