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Biomedical subjects

E Brard

Publications and source records attributed to E Brard.

At least 19 recordsLinked to original sources

[Estradiol and cell division: evidence for an indirect effect].

Castrated Quails were perfused for 24 h with estradiol-17 beta (E2: 2 ng/mn) through either the jugular vein or the portal vein. The parameters compared included: plasma E2 levels, changes in oviduct weight, DNA and soluble protein content, estrophilin concentration in nuclear preparations of oviducts and progestophilin concentration in the cytosol of oviducts. The cumulative results suggest that: (1) E2 affects the proliferation of cells by an indirect pathway that involve a message generated in the liver. (2) The control of the synthesis of cell-type specific protein required the direct action of E2 at the level of the oviduct cells.

Animals↗

Electrointraperitoneography: a new method for testing the pharmacological effects of drugs at the intestine level--preliminary note.

A recent and nontraumatizing method, electrointraperitoneography (EIG), has been used in the anesthetized rat in order to test its usefulness for the pharmacological study of drug effects on the electrical activity of the intestine. The results show that such a study is possible for different drugs. Advantages and disadvantages of the method are discussed.

Action Potentials↗

[The effect of estradiol benzoate on liver function, cholesterol metabolism and bile acids in the quail].

Immature female quails were treated for 6 days with estradiol benzoate at daily 0.01-, 0.02-, 0.01-, and 1-mg dosages. At the end of treatment, bile outflow, biliary cholesterol (CST), and bile acid (BA) secretory rates and liver, bile, and serum CST and BA levels were determined. Some quails were used to measure the ratio (R) of the rates of intravenously injected [2-14C]acetate radioactivity incorporation in cholic (C) and chenodeoxycholic (CDC) acids excreted in bile. The oestrogenic treatments at doses greater than 0.01 mg/day caused a marked disturbance in hepatic function and in CST and BA metabolism: they induced an increase in relative liver weight, liver CST stores, serum CST, C, CDC, and SGOT levels and in choleresis (respectively up to 56, 57, 650, 6000, 700, 42, and 235% increase at the daily 0.1-mg dosage) and they decreased bile total BA and CDC levels, bile and serum CDC to C level ratios, and R ratio (by 71, 82, 69, 84, and 58%, respectively). An increase in the bile salts independent fraction of bile was responsible for hypercholeresis, whether alone at low dosage or in conjunction with other factors at higher dosage. These results are compared with those obtained in mammals, particularly in the rat.

Animals↗

The effect of hypophysectomy on the quail's oviduct response to low and high doses of estradiol benzoate.

The response of the quail's (Coturnix coturnix Japonica) oviduct to different doses of estradiol benzoate (EB) was explored in ovariectomized and ovariectomized-hypophysectomized animals. Doses of EB ranged from 10 microgram to 1 mg/animal daily for 6 consecutive days; animals were sacrificed 24 h after the last injection. Controls were injected with olive oil. Parameters thought to reflect stimulation of the oviduct were 1) wet and dry weight, 2) DNA, 3) RNA, 4) soluble proteins, 5) ovalbumin, and 6) morphological changes at the level of magnum's mucosa. A statistical significant difference in several of the parameters listed was found between the effect of different doses of EB and whether the injection was done in ovariectomized or in ovariectomized-hypophysectomized animals. The dose response with EB for cell proliferation and induced proteins accumulation (ovalbumin) show that it takes considerably more EB to maximally stimulate ovalbumin accumulation when compared with cell proliferation. Hypophysectomy decreases the oviduct responses to high EB doses. Ultrastructural studies of the magnum mucosa confirm these biochemical results. The evidence presented suggesting an EB dose-dependent difference induction of specific cellular responses in the presence and absence of the pituitary in quails are the basis to postulate the contributing role of the pituitary in the parameters measured.

Animals↗

Study of the motility of the avian oviduct with chronically implanted electrodes.

Electrical activity was recorded in conscious hens from chronically implanted electrodes in the smooth muscle layers of the oviduct. Transport of the egg through the magnum resulted from an inhibition of the electrical activity in the oviduct cranial to the egg and an increased spiking activity caudally. During an ovulatory cycle the progression of the egg was related to four different patterns of the uterine motility: within a sequence, the ovulatory cycles varied according to the duration of Phases 3 and 4.

Action Potentials↗

[Ciliogenesis in the mucous cells of the quail oviduct. II. Hormonal control].

The hormonal control of ciliogenesis and transformation of mucous cells was studied in the oviduct (magnum) of ovariectomized quails. Estradiol benzoate induces ciliogenesis with doses varying from 10 mug/day to 100 mug/day after 6 days of treatment. With 100 mug/day, differentiation of some mucous cells is also induced as well as the formation of transitory "mixed cells" which are in the process of ciliogenesis and contain mucous granules. Associated with progesterone (1 mg/day), estradiol benzoate (10 mug/day) induces the differentiation of mucous cells and ciliated cells. The luminal epithelium of quails injected with this mixture is similar to the luminal epithelium observed in the oviduct of laying quails. With the same dose of progesterone (1 mg/day) and 20 mug/day of estradiol benzoate for 6 days, ciliogenesis is completely inhibited. All epithelial cells are secretory cells. Transformation of 50% of the mucous cells into ciliated cells is obtained by following the previous estradiol-progesterone treatment with the injection of estradiol benzoate (20 mug/day) for 3 days. Divisions of mucous cells were also observed. It is also possible to induce ciliogenesis in some mucous cells by withdrawing both hormones for 3 days. In this case, no cell divisions were observed.

Animals↗

[Motricity of the female genital apparatus in mammals. Hormonal correlations].

The motility and the pharmacological reactivity of the uterine tract of mammals are linked with the ovarian cycle and the gestation. In the birds, the study of general scheme of the hormonal mechanism and the uterine motility involued in the ovulation, the egg formation and the uterine dilatation can be used as an experimental model of the mammalian gestation.

Animals↗

[Exploration of digestive electrophysiology using a new technic : electrointraperitoneography (EIG)].

A new and simple method, the electrointraperitoneography (E.I.G.) is described and used for the recording of the digestive motility in conscious dogs and in anesthetized rabbits and rats. With the E.I.G. method, we have found the two types of potentials which characterise the electrical activity of the small intestine : the basic electrical rhythm (B.E.R.) and the action potentials (spikes).

Anesthesia, General↗

[Spatio-temporal development of Walker tumor implanted in the stomach wall of the Wistar rat].

Simulated gastric cancers have been realised in rats with injection of 0,1 ml of tumour cells suspension in the antral wall. A macroscopic and a microscopic study have been done. The antral tumour showed a constant growth pattern and rats died between 12th to 16th days after tumour implantation. During the first days (1 to 9) the tumour growth is relatively slow, the tumour does not extend out of the antral wall and remains in the submucous part of the gastric wall. After this time, the tumour growth is faster and the anatomicals structures of the wall are destroyed. It is possible with our method, to induce gastric cancer in large series of rats, which can be examined at different stage of Walker tumour growth.

Animals↗

[Effects of normebaric and hyperbaric hyperoxia on digestive motricity of the awake rabbit. I Antropyloric motricity].

The effects of normobaric and hyperbaric hyperoxia (short and long time) have been studied on the pyloric antrum motility of the rabbit. The results show the absence of effect of normobaric oxygen in short application (twenty to thirty minutes), but its inhibiting effect on the pyloric antrum motility in long time application. The hyperbaric hyperoxia slows down the frequency of the pyloric antrum contractions so much more the pression is higher. This effect is independant of the speed to which the pression is set up, and also of the moment of day where the experiment is done.

Animals↗