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Biomedical subjects

J P Raynaud

Publications and source records attributed to J P Raynaud.

At least 127 records · Page 7Linked to original sources
PubMed1979

Reference compounds for the study of moxestrol metabolism.

Reference compounds for the subsequent identification of the metabolites of the potent estrogen, moxestrol (R 2858) , in various species were isolated from the bile of phenobarbital pretreated rats or obtained via enzymatic hydroxylation by microorganisms. A few of them were prepared by chemical synthesis. The structures of all these compounds were determined by physical and chemical methods.

Animals↗
PubMed1979

Antidopaminergic activity of estrogens on prolactin release at the pituitary level in vivo.

Treatment of female or male rats with estradiol benzoate led to an almost complete reversal of the inhibitory effect of low doses of dopamine on prolactin secretion. These data indicate that estrogens which have previously been shown to exert a potent antidopaminergic activity on prolactin secretion in anterior pituitary cells in primary culture have similar effects in vivo.

Animals↗
PubMed1979

Effects of estrogens on the characteristics of [3H]spiroperidol and [3H]RU24213 binding in rat anterior pituitary gland and brain.

Since estrogens have been found to exert a marked inhibitory effect on dopaminergic action at the anterior pituitary and striatal levels in the rat, the effect of estrogen treatment has been studied on the binding characteristics of the dopamine (DA) antagonist [3H]spiroperidol and of the new DA agonist [3H]N-n-propyl-N-phenylethyl-beta-(3-hydroxyphenyl)ethylamine hydrochloride ([3H]RU24213) in rat striatum, nucleus accumbens + olfactory tubercle, frontal cortex and anterior pituitary gland. Specificity of binding was carefully examined in order to investigate possible changes of the agonist and antagonist states of the DA receptor. Estrogen treatment led to a small increase (approx. 20%) of [3H]spiroperidol and [3H]RU24213 binding in rat striatum, nucleus accumbens + olfactory tubercle and frontal cortex while no significant effect was found in the anterior pituitary gland. That the increased binding is due to a corresponding increased number of binding sites and not to higher affinity is indicated by the absence of effect of estrogen treatment on the IC50 values for displacement of the two labeled ligands by a variety of unlabeled compounds. Specificity of binding of DA agonists and antagonists remained unchanged after estrogen treatment. The present data suggest that the potent desensitizing effect of estrogen on DA action at the striatal and pituitary levels is exerted at a step subsequent to binding of DA to its receptor.

Animals↗
PubMed1979

Possible luteolytic effects of luteinizing hormone-releasing hormone in normal women.

The administration of five subcutaneous 250-microgram doses of lutienizing hormone (LH)-releasing hormone (LHRH) at 4-hour intervals, the first injection being given at 8 A.M. on 1 or 2 consecutive days between days 1 and 9 following the LH surge in normal women, shortened the luteal phase from 1 to 4 days in 16 of 17 treatment cycles. There was a better efficiency of treatment when LHRH was administered on days 6 to 9 after the LH surge as compared with days 1 to 5. In fact, the luteal phase was shortened from 3.3 +/- 0.2 days versus 1.4 +/- 0.2 days (P less than 0.01) and the serum progesterone level was decreased to 44% +/- 6% versus 71% +/- 6% of control levels (P less than 0.01) when the neurohormone was injected late as compared with early in the luteal phase. The present data raise the possibility of a luteolytic effect of LHRH in normal women and indicate the interest of such a near-physiologic approach for the control of luteal function and time of appearance of menses.

Adult↗
PubMed1979

Luteolytic effect of intranasal administration of [D-Ser(TBU)6,DES-Gly-NH2(10)]-luteinizing hormone-releasing hormone ethylamide in normal women.

Intranasal administration of two doses of potent agonist of luteinizing hormone (LH)-releasing hormone (LHRH), [D-Ser(TBU)6,des-Gly-NH2(10)]LHRH ethylamide (500 micrograms), a 8 A.M. and 5 P.M. on 1 day between day 4 and 9 following the LH peak in six normal women during two consecutive menstrual cycles shortened the luteal phase from 13.6 +/- 0.3 days to 10.9 +/- 0.3 days (mean shortening, 2.7 days; range, 0.5 to 4.5 days) and reduced plasma progesterone levels to 61.3% +/- 9.2% of control. Hormone changes were followed by daily measurements of plasma LH, follicle-stimulating hormone, 17 beta-estradiol, and progesterone during two pretreatment cycles, two treatment cycles, and two post-treatment cycles. No side effect was observed, and apparently normal cycles occurred immediately after treatment. The present data indicate that the intranasal administration of a potent LHRH agonistic analog can induce luteolysis and control time of occurrence of menses in normal women. This finding opens the possibility of a new and physiologic approach to fertility control.

Administration, Intranasal↗
PubMed1979

A radioreceptor assay for benzodiazepines.

A simple, rapid and sensitive radioreceptor assay for determining benzodiazepines in serum is based on the displacement by the drug of specific [3H]diazepam binding to a membrane fraction from rat brain. The limit of detection of the more active benzodiazepines is about 0.5 ng. Diazepam, nitrazepam, clobazam and HR 458 have been assayed in human serum after a single oral clinical dose. The results can be used for determining pharmacokinetic parameters. The technique measures not only the parent benzodiazepine but also clinically active metabolites.

Animals↗
PubMed1979

Dictyocaulus viviparus in calves: quantitation of antibody activities in sera and respiratory secretions by immuno-enzymatic analysis.

An enzyme-linked immunosorbent assay (Elisa) which is in detail described here has been adapted to trace antibody production in different fluids from infected calves. Seven calves were infected both with Dictyocaulus viviparus, and with several intestinal nematodes. Antibodies against an antigen prepared from Dictyocaulus viviparus adult worms were first detected during the 5th week post-infection, both in serum and nasal secretions, and were also observed in bronchial washings of the same calves slaughtered 53 days post-infection. IgA antibodies were never evident in the serum but were found in limited quantities in nasal secretions. In bronchial washings at slaughtering, a significant part of antibody activity is accounted for by the local IgA production.

Animals↗
PubMed1979

[An introduction to synthetic progestogens pharmacology (author's transl)].

Synthetic progestins differ in their progestomimetic and other endocrine effects. Their affinities for different steroid hormone receptors have been measured and their pharmacological activities (progestomimetic, uterotrophic, anti-estrogenic, androgen and anti-gonadotrophic) have been evaluated concomitantly. Derivatives of the pregnane series are basically progestomimetic only, whereas derivatives of the norandrostane series have distinctly androgenic and anti-estrogenic properties. A knowledge of these various activities facilitates the choice of an appropriate therapy.

Androgen Antagonists↗
PubMed1978

[Inhibitory effects of LHRH on LH receptors in the rat testis].

A single injection of LHRH to the adult male rat, as of its analog [D-Ala6, des-Gly-NH102] LHRH ethylamide, resulted in a marked decrease in LH receptors in the tests. Plasma testosterone level and the weight of the seminal vesicles and prostate were also decreased after treatment. These data demonstrate that LHRH can decrease the sensitivity of LH receptors and testicular function in the rat.

Animals↗
PubMed1978

[Inhibitory effects of LHRH on ovarian LH receptors in rats].

The administration of LHRH or of its analog [D-Ala6, des-Gly-NH10(2)] LHRH ethylamide to the female rat on day 10 of gestation resulted in termination of pregnancy and in a marked decrease in ovarian LH receptors and plasma progesterone level. Asingle injection of either compound during diestrus I also led to a decrease in LH receptors. These data demonstrate the high sensitivity of the control of ovarian LH receptors by circulating gonadotrophins and suggest that the contraceptive action of pre- and postcoitally administered LHRH is mediated by negative control of LH receptors.

Animals↗
PubMed1978

[Luteolytic action of LHRH in women].

Several subcutaneous administrations of 250 microgram of LHRH (4 or 5 adminstrations at 4-hourly intervals per day) between the 2nd and 7th day post-ovulation in 4 normal women led to early luteolysis as demonstrated by a fall in serum progesterone concentration and early onset (2 to 3 days earlier) of menstruation.

Adult↗
PubMed1978

Double-blind crossover clinical pharmacology study comparing moxestrol (R 2858) and ethinyl estradiol in postmenopausal women.

The potency of 5 migrogram moxestrol (R 2858). 11beta-methoxy-17alpha-ethinyl-estra-1,3,5-[10]-triene-3,17-diol, administered orally, was compared to that of 25 microgram ethinyl estradiol in a double-blind crossover clinical pharmacology study of six postmenopausal women. At these doses, both compounds increased the eosinophilic index and decreased serum LH and FSH levels. A marked effect on circulating prolactin was observed only during ethinyl estradiol treatment.

Aged↗