Tetanie latente: action d'une eau minerale naturelle magnesienne (hydroxydase) / Tetany: action of natural magnesian mineral water (hydroxydase)

Chez un groupe de 10 sujets dont la tetanie latente a ete verifiee par une echelle specifique validee, appelee echelle de spasmophilie, un traitement par deux cures d'eau d'Hydroxydase a ete mis en place. Cette... (AU)

[Changes in plasma prolactin and magnesium in male rats treated with thioproperazine and/or bromocriptine]. / Variations de la prolactine et du magnésium plasmatiques chez le rat mâle traité par la thiopropérazine et/ou la bromocryptine.

The Ca2+ dependent release of both dopamine (DA) and prolactin (Prl) is modified by stress. Plasma magnesium (Mg) concentrations are also modified. Therefore, we have investigated on plasma (P) Mg and Prl, the immediate and delayed effects of one, five or six daily injections of bromocriptine (BMC, 200 micrograms/100 g) and thioproperazine (100 micrograms/100 g), respectively agonist and antagonist of pituitary DA receptors. One hour after injection of either drugs, an increased P Mg is observed while P Prl is increased or decreased. No correlation is, thus, established between P Prl and P Mg changes. The P Mg increase is long-lasting after BMC, transitory after thioproperazine as shown by determinations performed 23 h after the 5th injection. When the two drugs are simultaneously given, no important modifications of P Mg are observed. The mechanisms and consequences of this P Mg increase are discussed. During stress, the hypermagnesemia could modulate the Prl secretion and action, hindering its secretion on one hand, and potentiating its action on target-organs, on the other hand.

[Inhibition of nidation in mice by modification of the environment and pheromones. Re-establishment by prolactin and thioproperazine]. / Inhibition de la nidation chez la souris par modifications de l'environnement et phéromones. Rétablissement par prolactine et thiopropérazine.

325 mated mice (evidence of a vaginal plug, J1) were divided into 8 groups, 246 were subjected to various kinds of stress before day 7 of gestation: 120 were placed singly in boxes and/or transferred to different ones: 75 were exposed to alien males with or without box transfer. 85% of the 50 unstressed females did, in fact, become pregnant. Isolation by itself did not modify the course of gestation. Transfer to a new box (74 females) along with isolation from days, 1, 2, 3 or 4 on reduced the percentage of pregnant females to 55%. Exposure to a strange male in the common box of females (26 females) reduced it to 55%. Isolation of a single female with a strange male, along with transfer (49 females; Bruce Effect) on day 4, 5 or 6 reduced this percentage to 25, 6 or 20% respectively. In addition when the stress occurred on day 4 the number of implantations was greatly reduced. A daily s. c. injection of B prolactin or of thioproperazine on days 4, 5 and 6 prevented the onset of the pregnancy block (47 females). If the 325 mice are separated into 2 groups, those ind whom gestation was maintained and those who aborted, ponderal growth greatly increased in the former; their adrenal glands weighed less, and their preputial glands weighed more. An excessive secretion of corticosteroids in non-pregnant females could be the cause of the inhibition of prolactin release. These results suggest that the effects and probably the implicated mechanisms are the same for pheromones and environmental changes as prolactin and thioproperazine prevent the effects in both cases. The variation in the susceptibility of mice could be due to genetic factors that play a primary role in hypophyso-adrenal response to emotional stress.

[Comparison of the action of an impeded estrogen, frideron, and of estradiol on the seminal vesicles and on the weight of the testicles and accessory sex glands in the rat. II]. / Comparaison de l'action d'un oestrogène entravé, le fridéron, et de l'estradiol sur la lignée séminale et sur le poids des testicules et des glandes sexuelles annexes du rat. (II).

We have undertaken a comparative study on the effects of estradiol and of an impeded estrogen, zeranol, in the prepubescent Wistar male rat. Both had an inhibitory effect on the secretion of F.S.H. in the spermatogenesis test. Nine injections of estradiol or nine ingestions of zeranol had a restraining effect with a dose of 0.5 microgram of estradiol or of 500 micrograms of zeranol (for 100 g of body weight). With some animals, spermatogenesis is interrupted and the weight of the testicles decreased; the treatment is more active with stronger doses: 2 micrograms of estradiol interrupted spermatogenesis in 10 rats out of 11, 1.000 microgram of zeranol interrupted it in 10 rats out of 13. A weak dose of either estrogen (0.05 microgram of estradiol or 20 micrograms of zeranol) stimulated the growth of the seminal vesicles, the prostate gland and the preputial glands. Strong doses decrease the weight of the preputial glands, and even more the weight of the prostate gland (10 micrograms of estradiol, 1.000 microgram of zeranol). They are ineffective on the seminal vesicles. The effects of 2 micrograms of estradiol on the testicles and the accessory sexual glands are completely inhibited by the simultaneous administration of 2 U.I. of P.M.S. rich in FSH.

[Comparative action of an impeded estrogen, zeranol, and estradiol on some receptors in the female rat (author's transl)]. / Action comparée d'un oestrogène entravé, le fridéron, et de l'estradiol sur quelques récepteurs de la ratte.

We have studied the estrogenic action of zeranol and have compared it to the action of estradiol on the uterus--the vagina, the mammary gland and the pituitary gland of the pre-pubescent, castrated female before the opening of the vagina. The weakest dose at which estradiol is active is 0.1 microgram injected for a period of three days : it is capable of opening the vagina on the fourth or fifth day and of developping the uterine glands to the maximum : injected over a period of ten days it provokes a hypertrophy of the pituitary gland : only the mammary gland reacts exclusively to doses other than physiological ones. The estrogenic action of zeranol is weak : 1 mg administered orally for three days is necessary in order to reproduce the same effects of 0,1 microgram of estradiol on the opening and the keratinisation of the vagina and on the stimulation of the uterine epithelium ; its efficacy is greater on the uterine glands (250 micrograms is equivalent to 0.1 microgram) and on the pituitary gland (500 microgram reproduce the hypertrophy provoked by 0,1 microgram). The doses administered are by 100 g of body weight. The uterine glands are more sensitive to stimulation by the estrogens employed (estradiol, zeranol) than is the uterine epithelium. The study of the relation between the estrogenic dose and the response of the uterine weight shows that the gradient of the curve is weaker with zeranol than with estradiol. This observation shows that zeranol behaves as an impeded estrogen.

[Morphological variations of rat mammary glands according to the age and the environmental factors (author's transl)]. / Variations morphologiques des glandes mammaires de la ratte en fonction de l'âge et de l'environnement.

We took the microscopic study of the mammary gland lactation as a test of prolactin (Prl) secretion in female rats. Aging is liable to cause the acini secretion in 7 females out of 17. Constant light or the repetition of stresses which are known to increase the serum Prl concentration have no effect in young females' mammary gland but always cause an abundant lactation in the 18 old females. In this test, aging and environment can be synergistic.

[Action of an antiestrogen agent, tamoxifen on the uterus and vagina of the ovariectomized rat]. / Action d'un anti-estrogène, le tamoxifène, sur l'utérus et le vagin de la ratte ovariectomisée.

Tamoxifen has more or less strong estrogen influence according to the targets : a light one on the uterus (1 mg being much less strong than 0.25 microgram of estradiol), a dynamic one on the vagina (50 microgram of tamoxifen make the vagina open in as short a time as 0.25 microgram of estradiol do but the keratinisation is still not completed even with 1 mg of tamoxifen). We can still see this influence four days after the end of the treatment. This influence is weak on the uterus until the 11 th day and it is much stronger on the vagina until about the 8 th day. Tamoxifen has an antiestrogenic action when opposed to 20 microgram of estradiol : this action is limited as soon as you give a dosis of 50 microgram on the uterus and it is nearly total with a dose of 1 mg ; we can notice it on the vaginal only from 200 microgram on.

[Action of an antiestrogen agent, tamoxifen on the mammae of ovariectomized rats]. / Action d'un anti-estrogène, le tamoxifène, sur les mamelles de la ratte ovariectomisée.

We have been studying the estrogen and antiestrogen action of tamoxifen and of clomifen on the development and secretion of acini and of the galactophore canals of the mammary gland. The ICI (50 or 200 microgram) has no effect : the very strong dose of 1 mg gives a light stimulation of the acini secretion which can be compared to that of light doses of clomifen (20 or 50 microgram) or of estradiol (0.25 microgram). Only 10 microgram of estradiol alone allow the development, the opening and secretion of acini. With 20 microgram, this action is more apparent, not only on the often dilated acini, but also on the canals. Administered along with 20 microgram of estradiol, tamoxifen is slightly antagonist with 50 microgram, strongly antagonist with 200 microgram, and completely antagonist with 1 mg. 50 microgram of clomifen are inefficient ; it is synergetic if the treatment starts and is over 4 days before the estradiol treatment.

[Action of estradiol and testosterone on the preputial glands of the rat fetus]. / Actions de l'oestradiol et de la testostérone sur les glandes préputiales du foetus de rat

PIP: The effect of increasing doses of estradiol, 50 mcg-1 mg, or testosterone propionate, 500 mcg-10 mg, given to a pregnant rat on pregnancy Day 14-21 on development of the preputial gland in male and female fetuses was compared to the effect on anogenital distance and retardation of weight gain. Estradiol in increasing doses stimulated development of prepuital gland in both sexes, increased dispersion of data in males, and high doses stimulated gland development in females almost as much as in males. Estradiol at 50 mcg to 1 mg decreased anogenital distance in males from 3.2 to 1.6 mm, and increased it in females from 1.1 to 1.7 mm. Testosterone propionate stimulated preputial gland development in females, and increased weight even more so; it inhibited gland development slightly in males. Testosterone at 500 mcg-10 mg augmented anogenital distance in females, but had no effect on males except at 10 mg.^ieng