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Biomedical subjects

B Rocle

Publications and source records attributed to B Rocle.

5 recordsLinked to original sources
PubMed1984

Plasma testosterone transport in primates.

All primate species, including Old and New World primates and prosimians have a plasma testosterone-estradiol binding globulin (TeBG), which is a glycoprotein and has a similar mobility in polyacrylamide gel electrophoresis. In New World primates the TeBG binding capacity for [3H]testosterone was higher and its affinity lower than in Old World primates. These changes were associated with high unbound plasma testosterone concentrations in these species. Binding parameters of TeBG in prosimian species varied markedly. Thus, in primate evolution TeBG was conserved despite marked differences in binding characteristics. In New World primates changes are associated with high total and unbound testosterone, a finding concordant with alterations of other steroid hormones concentration in these species with "generalized steroid hormone resistance".

Animals↗
PubMed1979

LSH and FSH autonomous secretion in long-term pituitary tissue culture.

Pituitary tissue from 2- to 6-day-old male rats was cultivated for up to 136 days in medium containing fetal bovine serum, but without added steroid or hypothalamic extracts. After 40 to 70 days of sustained release of LH and FSH at a very low level, there was an increase in the quantity of both, and a plateau of depressed secretion. LH was identified by immunoreactivity in two radioimmunological systems and in gel chromatography. Little, if any, alpha-subunits were liberated in these cultures. It is concluded that basal production of LH and FSH is a constitutive activity of the gonadotropic cell.

Animals↗
PubMed1979

[Gonadotropic activity in cultured hypophyses. 1. Adult male rats].

Adenohypophysial tissue of adult male rats was cultivated for 15 days, in order to eliminate influence from rats other organs, and to obtain a stable spontaneous gonadotropins release in culture medium. It was then stimulated from 15th to 25th day of culture with LH-RH and/or testosterone. LH-RH-induced effects : 2 to 6 times increased LH release, and 2 times increased FSH release, declined from 15th to 25th day, suggesting a loss of receptivity to the stimulating hormone. Testosterone had two direct effects on adenohypophysis : first, when added alone to the culture medium, it did not inhibited LH release and stimulated (x2) FSH release; second, it partially inhibited gonadotropin response to LH-RH.

Animals↗
PubMed1979

[Gonadotropin activity of newborn rat adenohypophysial tissue in culture compared to that of adult rats (author's transl)].

It has been suggested that low circulating levels of androgens and gonadotropins found in impubertal subjects is due to a low -- setted feed-back regulation system, i.e. sensitivity of that system is higher than that of adult subjects. Cultures of adenohypophysial tissue of 2 to 6 days old male rats were performed and gonadotropins release compared to that obtained from similarly conducted adult male rats pituitary cultures (previous paper). Newborn rat hypophysis was more sensitive to factors stimulating LH release (LH-RH) and FSH release (testosterone). In contrast, testosterone inhibition of gonadotropins response to LH-RH was similar to that of adult tissue. Since trophic factors influence could not be totally excluded, it was concluded that pituitary tissue does not show marked variation of sensitivity with age.

Age Factors↗