Biomedical subjects

L Thieblot

Publications and source records attributed to L Thieblot.

At least 19 recordsLinked to original sources

PubMed1979

[Purification of pineal antigonadotropic factor (author's transl)].

Pineal activity on hypothalamo-hypophyso genital axis is well established. The mechanism is not simple, since progonadotropic or/an antigonadotropic activity were described. The biochemical isolation of the potent factor has been assayed. Several substances: melatonin, AVT, peptides have antigonadotropic properties. In this paper, we report many experiments concerning isolation and purification by several chromatographies of the factor (probably peptidic), that we believe to be responsible of antigonadotropic activity. Biological activity of the substance is proved by "in vitro" methods and radio immunoassays. This component is quite pure because electrophoresis on gel polyacrylamid reveals only one strip. Gel Sephadex G10 chromatography indicates a probable MW is between 500 and 1,000. This component causes an important inhibition of pituitary LH discharge (in vitro methods).

Animals↗

PubMed1978

Circadian variations of ovarian ascorbic acid depletion in response to luteinising hormone in the rat.

The ovarian ascorbic acid (OAA) was titrated, three hours after an I.V. injection of either saline or LH, administered to 46 day-old Sprague Dawley female rats pretreated with P.M.S., H.C.G., and estradiol benzoate (and undecylate). The rats were killed at specific times along the 24-hour scale (L.D. 12:12; L 06(00) to 18(00); Ambient temperature 24 degrees C +/- 2 degrees C). The OAA content varied with a statistically significant circadian rhythm in the controls. The minimum dose of LH effecting OAA depletion varied systematically with the circadian system phase. OAA depletion increases with the dose of LH, and also depends on the circadian time that the animal is killed; it is maximum at the same time that the OAA peak is found in the controls. The slope of the linear regression (quantity of OAA as a function of the logarithm of the LH doses administered) is always significant, but varies over the 24-hour span; in consequence the LH biological titration must be carried out rapidly, the optimal circadian time for killing the animals is about 16(30).

Animals↗

PubMed1975

[Biological assay of hypophyseal gonadotropins in the male rat (statistical study)].

The reproductibility, the experimental and statistical procedures of FSH and LH bioassays are studied. The estrogen pretreatment of animals increases, considerably the responsiveness and reliability of the LH bioassays. FSH levels have been determined, by the methods for parallel line assays, in the pituitary gland of normal rats and three days or seventeen days orchiectomized rats.

Animals↗

PubMed1975

[Action of an ovulation stimulator on the genital function of the female rat].

Effect of cyclofenil on genital function implied organs, is studied in cyclic female rats injected s. cut: 0.5, 5 or 50 mg/kg/day, during 12 days. The treatment increases pituitary, adrenal and uterine weights, decreases ovarian weight, adrenal and ovarien cholesterol. These data suggest that cyclofenil acts directly or undirectly at different levels of hypothalamo-pituitary-genital axis with central inhibition and light peripheral stimulation.

Adrenal Glands↗

PubMed1975

[Interrelationship between adrenal cortex and genital apparatus of the male rat].

Interactions between gonadal hormones and adrenocortical function have been studied in the male rat. After injection (im) of testosterone, the accessory reproductive organs are more stimulated in the castrated rats than in the castrated adrenalectomized rats. Gonadectomy increases lipids, cholesterol and corticosterone in adrenal glands and plasma corticosterone levels. Testosterone reverses these effects.

17-Ketosteroids↗

PubMed1972