Biomedical subjects

Y Chambon

Publications and source records attributed to Y Chambon.

At least 37 records · Page 2Linked to original sources

PubMed1980

[Dynamics of the elevation of hepatic polyamines after partial hepatectomy in the rat].

Following McCormick's method we have studied the rates of spermine, spermidine and putrescine in regeneration Wistar-rat liver until 4 days posthepatectomy. The putrescine rate exhibits marked increase during the first 6 hours, then slowly drops and returns about to its original value within 90 hours. The concentrations in spermidine and spermine both increase until 10 h; whereas the first concentration keeps on rising, the second one declines to control level within 24 h, but rises again after 72 h. This evolution can be easily explained on the basis of previous studies and may be interpreted in relation to cell divisions which mark early liver regeneration.

Animals↗

PubMed1979

Role of the epididymis in reabsorption of inhibin in the rat.

The effects of efferent duct ligation, orchidectomy and orchido-epididymectomy were compared at 36 h. This showed that the rat epididymis is capable of maintaining a negative feedback control of FSH secretion. Epididymal extracts contained a substance of tubular origin capable of reducing FSH secretion. This substance is a protein and is found in the caput region but not in the caudal region of the epididymis. A new role can be assigned to the head of the epididymis: that of reabsorbing, together with testis fluid, the inhibin produced by the seminiferous tubules, which thus passes into the bloodstream and provides a feedback regulation of plasma FSH.

Absorption↗

PubMed1977

[Testing synergism between ethinyl estradiol and norethisterone on the histamine-induced deciduoma and vaginal mucification of castrated rats].

Through the histaminic deciduoma test and a vaginal mucification test, we have endeavoured to show that, in spayed female rats there exists a possibility of synergism between ethynylestradiol and pure norethisterone per os. No synergism could be shown in the former test, owing to, or so it seems, a lack of deciduogenic power proper to norethisterone. The latter test showed, indeed, that ethynylestradiol can, in low quantities, bring about a synergism on the mucifying properties of norethisterone, whereas, in large quantities, it creates an antagonism on the aforesaid properties.

Animals↗

PubMed1977

[Effects of ligation of the ductuli efferentes or the epididymis on testicular function and secretion of gonadotropins in rats].

One week after ligating the vasa efferentes or the corpus epididymis in adult Wistar rats, we have studied the histological structure of the testes, measured their weights, as well as those of the seminal vesicles, and estimated F.S.H. and I.C.S.H. levels in the plasma through radioimmunoassay. Whereas ligating the corpus epididymis has not effect, ligating the efferent ducts damages the germinal line, without any damage on the Leydig cells; it also raises F.S.H. circulating level, if not I.C.S.H. level. We therefore confirm an inhibin production by seminiferous tubules, this hormone returning to the blood stream in the testis or rather in the head of epididymis as our research in progress suggests.

Animals↗

PubMed1977

[Synergistic effects of ethynylestradiol and norethisterone on the formation and lengthening of uterine lace in immature rabbits].

We have shown, through a test proceeding from the McPhail test, in the immature rabbit female, the existence of succession and simultaneity synergisms between ethynylestradiol and pure or impure norethisterone, given by oral route. The estrogen, administrated before the progestative, is able to potentialize the action of the latter on the building of the endometrial lace in 5 days, more than on the lengthening of it in 15 days. Ethynylestradiol, absorbed with norethisterone, strengthens the effects of the latter on the second phenomenon more than on the first one. Absolute and relative doses of the estrogen and of the progestative differ only lightly according as norethisterone is pure or not pure, because of the more potent estrogenicity of the impure norethisterone.

Aging↗

PubMed1977

[Evidence, in the epididymis, of a strong lowering factor for blood FSH in rats].

The supernatant of centrifuged epididymis homogenates was injected in the peritoneum of castrated Wistar rats for three days. It involves a strong decrease of FSH in the blood plasma, without a significant change of LH and LTH, measured by radioimmuno-assay. Now ligating the vasa efferentes --- but not the epididymis corpus --- involves an increase of the plasma FSH, as we showed in a previous paper. Then we conclude that testicular inhibin gets into the blood stream through the head of the epididymis.

Animals↗

PubMed1977

[Strong increase in hepatic and blood histamine levels after partial hepatectomy in rats].

The histamine rates, when established by fluorometry, according to the method of Shore, in the residual liver and in the whole blood of Wistar-Commentry male rats, quickly increase after partial hepatectomy carried out as described by Higgins and Anderson. The levels reach a peak 24 h after hepatectomy, then progressively lower, and on the 4th day are almost equal to the rates of control or sham operated animals.

Animals↗

PubMed1977

[Evidence of an epididymis factor inhibiting the hypothalamic synthesis of FSH-RH in the rat].

We have measured, by radioimmunoassay, FSH and LH in the blood plasma and in the hypophysis of castrated male rats, injected with epididymal inhibin; we have also evaluated the FSH and LH releasing activities of their hypothalamus by measuring plasma FSH and LH levels of spayed female rats, treated by hypothalamic extracts of the previous rats. The FSH and LH pituitary levels do not change compared with controls, and it is impossible to know if inhibin acts directly on hypophysis; it is likely that, directly or indirectly, inhibin restrains at the same time the synthesis and the release of FSH. On the contrary, the hypothalamic extracts lose their FSH-RH, but not their LH-RH, activities; then, inhibin operates on hypothalamus by suppressing of the synthesis of FSH-RH.

Animals↗

PubMed1977

[Effects of tritoqualine on hepatic and blood levels of histamine after partial hepatectomy in rats].

Looked as a specific inhibitor of histidin-decarboxylase, tritoqualine has been injected subcutaneously to Wistar rats immediately after partial hepatectomy and, then, once in 24 hours until 72 hours. It has thus provoked : an unexpected, but transient rise (reaching its apex 3 hours after the operation) of the hepatic and blood histamin concentrations ; then, the expected decrease (more durable and greatest at 48 hours) of the same concentrations. Therefore, an effect of tritoqualine on the liver regeneration might be expected, whether histamin plays some part in this phenomenon.

Animals↗

PubMed1977

[Effects of aminoguanidine sulfate on hepatic and blood levels of histamine after partial hepatectomy in rats].

Known as a specific inhibitor of histaminase, amino-guanidin sulfate has been administered subcutaneously to Wistar rats immediately after partial hepatectomy, then once in 16 hours until 80 hours. It has thus provoked: an initial rise of the hepatic and blood rates of histamin, which is transient and reaches its apex 6 hours after the operation; then, a new rise of these rates, which lasts and even is, in percentage, maximum at 72 hours. Therefore, amino-guanidin sulfate is available to estimate the influence of the endogenous histamin upon liver regeneration.

Amine Oxidase (Copper-Containing)↗

PubMed1975

[Effects of ethinyl estradiol compared with norethisterone (pure or contaminated) on vaginal keratinization of castrated rats].

Norethisterone samples are often contaminated by estrogen traces which can be measured by mass spectrometry and which invest the progestative with estrogenic properties in the Allen and Doisy test. Therefore, one had better, in pharmacodynamic experimenting, use samples that have been purified by chromatography or that are pure out of synthesis. However, one will not forget these are not without some estrogenicity, a fact which seems linked to the very nature of the norethisterone molecule.

Animals↗

PubMed1968