l-fenfluramine in tests of dominance and anxiety in the rat.

l-Fenfluramine (1.25 and 2.5 mg/kg) significantly reduced the success of dominant rats competing with untreated middle rank rats for chocolate. In resident rats, l-fenfluramine (2.5 mg/kg) significantly increased the number of submissions, and the time spent submitting, to untreated rats intruding into their home-cage territory; it also significantly reduced the number of kicks directed at, and the time spent kicking, the intruder; and the incidence of, and time spent in, aggressively grooming the intruder. When the intruder rats were treated with l-fenfluramine the only significantly change was a decrease in the number of wrestling bouts and the time spent wrestling. Since l-fenfluramine did not change other behaviours in this test (e.g. sniffing the opponent) the decrease in dominance behaviours was probably not secondary to nonspecific sedation. In the social interaction test of anxiety, l-fenfluramine (2.5 and 5 mg/kg) significantly reduced the time spent in active social interaction, and decreased motor activity. Analyses of covariance indicated that these were two independent effects. In the elevated plus-maze, l-fenfluramine (1.25-5 mg/kg) significantly decreased the percent number of entries made onto open arms, and (2.5 and 5 mg/kg) significantly decreased the percent of times spent on the open arms. The total number of arm entries was reduced by all doses (0.625-5 mg/kg). Analysis of covariance indicated that the decrease in percent of time spent on the open arms was secondary to the drop in overall activity. Thus there was no evidence of anxiolytic action in either of these tests, the changes indicating, if anything, anxiogenic effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma and urinary melatonin in male infants during the first 12 months of life.

Plasma and urinary melatonin, testosterone and luteinizing hormones were radioimmunologically assayed in 26 male babies during the first year of life. The results show that plasma melatonin levels are low during the phase of postnatal elevation of testosterone and luteinizing hormones. They subsequently increase when testicular activity decreases. Urinary elimination of melatonin does not vary during this period, suggesting the existence of variations in the synthesis or utilization of melatonin.

Variation of urinary melatonin excretion in humans during the first 30 years of life.

Urinary melatonin variation in humans were demonstrated to be a function of age. A radioimmunological assay was used. The values obtained, expressed as nmol x 24 h-1 x kg-1, progressively decreased from birth onwards, with a more accentuated and momentary inflection at the moment of the genital crisis in newborns and at puberty. The results obtained concern only melatonin and not its metabolites, as a result of the high specificity of the antibodies employed.

Structural immunochemistry of melatonin-BSA binding, model of amino and indole groups cross-linking.

The sites of fixation to bovine serum albumin of melatonin and of mono- and dimethylated melatonin identified by mass spectrometry and nuclear magnetic resonance, have been determined. The binding sites appear to be important in the conservation of the structural features necessary for the antigenicity of the molecule.

[Preliminary study of the synthesis, plasma circulation and urinary elimination of melatonin in man and the rat]. / Etude préliminaire concernant la synthèse, la circulation plasmatique et l'élimination urinaire de la mélatonine chez l'homme et chez le rat.

A structural immunochemical study has shown that fixation of melatonin on bovine serum albumin by formaldehyde occurs via reaction of both an indole NH group and the side chain, allowing extremely specific antibody production. Isotopic in vitro investigations and radioimmunological estimation of this hormone in man and in the rat shows that it is transported by plasmatic albumin in a 1/10(6) ratio and is eliminated in the urine as native material, 6-hydroxy melatonin and as an as yet unidentified metabolite.

[Prolactin: estimation and interest in clinical biology (author's transl)]. / Prolactine : dosage et intérêt en biologie clinique.

The recent development of radio-immunoassay of prolactin has permitted, in recent years, better understanding of its role in hormone regulation. In man, the secretion of prolactin is submitted to physiological variations dependent on sex, age and also environment. It is also modified by numerous drugs. Certain of them are used during stimulation tests and inhibition tests of the pituitary gland. The determination of basic prolactinemia and during dynamic tests is now a factor in basic diagnosis for the clinician who now has available efficacious chemotherapy (derived from rye ergot) in the treatment of hyperprolactinemia.

Preparation of anti-melatonin antibodies and antigenic properties of the molecule.

Anti-melatonin antibodies of high titer and good sensitivity were obtained by coupling melatonin to bovine serum albumin with formaldehyde and by immunizing rabbits with multifocal intra-dermal injections. A systematic study of cross-reactions with 14 compounds (indole, aromatic and imidazole derivatives) showed that the antibody had a high specificity for melatonin, low reactivities with 6-hydroxymelatonin and N-acetylserotonin and no detectable reactivity with 12 other derivatives. The roles of the indole nucleus and the side chain in the determination of the antigenic properties of the molecule are discussed.