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C Laugier

Publications and source records attributed to C Laugier.

At least 55 records · Page 3Linked to original sources
PubMed1986

Magnum morphogenesis during the natural development of the quail oviduct: analysis of egg white proteins and progesterone receptor concentration.

The histological development of the quail oviduct and the changes in concentrations of progesterone receptor, ovalbumin, conalbumin, ovomucoid and ovoglycocomponents are analyzed during the period spanning 7-35 days of age. The initiation of luminal epithelial cell proliferation is the first event of magnum growth. The epithelial cells begin to evaginate into subepithelial stroma and form tubular glands. Meanwhile, luminal epithelium starts cellular pleomorphism through ciliogenesis. No egg white proteins are detectable in the developing glands; at the same time, the concentration of the progesterone receptor increases from about 5500 sites/cell to 30,300 sites/cell. Tubular gland cells then begin to synthetize and accumulate egg white proteins, mucous cells differentiate in the luminal epithelium, and the cell proliferation decreases and finally stops. Compared with earlier studies dealing with the blood levels of estrogen and progesterone in developing quails during the same period, and the cellular changes induced in the oviducts of ovariectomized and ovariectomized-hypophysectomized quail by exogenous steroids, these results distinguish between the cellular responses that are physiologically controlled by estradiol and other responses that have multihormonal regulation.

Animals↗
PubMed1984

Opposite effects of glucocorticoid on estrogen-induced growth and differentiation of quail oviduct: demonstration by sequential treatments.

Control of the development and functions of avian oviduct is monitored by four classes of steroid hormones, including glucocorticoids. The effects of dexamethasone (DEX), a synthetic glucocorticoid, were studied via sequential treatments with estradiol benzoate, paying special attention to changes in estrogenic oviduct responses involving DNA synthesis and cell proliferation, ovalbumin accumulation and cell differentiation. DEX exerted an antagonistic effect upon estrogen stimulation when administered separately before or after estradiol benzoate (EB). Given before EB, DEX was more strongly antagonistic for DNA synthesis than when given simultaneously with EB. Administered after EB, DEX reversed EB-induced cell proliferation: the DNA content declined and the oviduct regressed. In the same way, protein and ovalbumin synthesis was inhibited and delayed by first intervention of DEX, and accelerated catabolism of ovalbumin and proteins was observed when DEX followed EB. DEX, which was ineffective alone, but synergistic on ovalbumin synthesis when given concomitantly with EB, prevented or dissipated the estrogenic effects, cell proliferation and secretory process when administered in sequential treatments.

Animals↗
PubMed1984

Development of the oviduct in quail during sexual maturation in relation to plasma concentrations of oestradiol and progesterone.

The macromolecular content (DNA, soluble proteins and ovalbumin) of the magnum and the plasma concentrations of oestradiol and progesterone were studied during sexual development of the Japanese quail. Rapid growth and differentiation of the magnum began between 21 and 28 days of age and rapidly reached the laying stage in about 20 days. This rapid change in magnum size occurred in a stepwise manner: cellular proliferation was observed first, followed by the synthesis and accumulation of specific proteins. Just before and during magnum growth, plasma oestradiol and progesterone concentrations followed different patterns: the initiation of epithelial cell proliferation was preceded by a sharp decrease in plasma progesterone. Maximum cell division occurred while plasma progesterone levels continued to decrease slightly; at the same time, oestradiol increased from 0.098 to 0.453 nmol/l. The decrease and finally the cessation of cell proliferation and the concomitant increase in ovalbumin concentration were related to almost constant levels of plasma oestradiol and increasing levels of plasma progesterone. Further development of the magnum (above 2.3 g weight) involving only the accumulation of secretory products was associated with an increased value of plasma progesterone. These data are consistent with the hypothesis that there are multiple hormonal signals controlling cell proliferation and synthesis of egg-white proteins in the oviduct. Progesterone may be one of the key signals that regulates the initiation of oviduct growth in the quail.

Animals↗
PubMed1983

Analysis of progesterone receptor in the quail oviduct. Correlation between plasmatic estradiol and cytoplasmic progesterone receptor concentrations.

Specific binding sites for [3H]-progesterone are found in the cytosol fraction of the oviduct of castrated, immature and developing quails. The optimal conditions to accurately measure the total cytoplasmic concentration of this progesterone receptor are described. The dissociation constant (KD) at 0 degrees C is 3.6 +/- 0.6 x 10(-9) M (mean +/- SE) for [3H]-P and the concentration of binding sites is 13.4 +/- 2 pmol/mg DNA in immature animals. This binding capacity is not altered even 2 weeks after ovariectomy. During sexual development, although the dissociation constant remains unchanged, the number of binding sites increases to 74.5 +/- 1.6 pmol/mg DNA just before the beginning of the laying cycle. The concentration of cytoplasmic P receptor is under the inductive influence of estradiol. In castrated quails, estradiol 17 beta (E2) perfusion through the portal vein at a rate below or equal to 2 ng/min for 24 hr does not increase plasmatic E2 concentration and consequently does not change [3H]-P binding sites concentration in the oviduct. While E2 perfusion rate exceeds the metabolizing capacity of the liver (6.8 ng/min), both plasmatic E2 level and oviductal P receptor concentration are increased. When E2 is perfused through the jugular vein, plasmatic E2 level increases with the dose of E2 but P receptor concentration only increases when E2 perfusion rate reaches to 2.0 ng/min for 24 h.

Animals↗
PubMed1983

Mechanism of estrogen action: indirect effect of estradiol-17 beta on proliferation of quail oviduct cells.

Experimental data were collected to test whether the effect of estrogens required a direct action of the steroid on their target cells for induction of (i) cell multiplication and (ii) cell-type-specific protein synthesis. Ovariectomized quails were perfused for 24 hr with several doses of estradiol-17beta (E(2)) (0.05-6.8 ng/min) through either the jugular vein or the portal vein. E(2) plasma concentrations increased progressively when the perfusion rate through the jugular vein was 0.5 ng/min and higher. With the portal vein, by contrast, E(2) plasma concentrations increased over the concentration in unperfused ovariectomized animals only when the perfusion rate was above 2 ng/min. An increase in DNA concentration per oviduct was observed regardless of the route of administration and the rate of perfusion, starting at 0.5 ng/min. Nuclear estrophilins increased when E(2) was perfused through the jugular vein at rates of 0.5 ng/min or greater. This same parameter was not increased in oviducts of quail perfused through the portal vein even at a perfusion rate of 2.0 ng/min. Progestophilins were induced in the oviducts of quail perfused through the jugular vein at rates of 2 ng/min and above; on the other hand, progestophilins were induced in birds perfused through the portal vein at rates above 2 ng/min. Ovalbumin was not induced in quail oviducts at any rate and route of perfusion. The induction of the synthesis of cell-type-specific protein (progestophilins, in this case) seems to require, however, the direct action of E(2). The E(2) concentrations effecting the induction of progestophilins were higher than those necessary to effect the proliferation of oviduct cells. These results suggest that the E(2) effect on cell proliferation is indirect, it involves an intermediary step at the liver, and it does not require increased concentration of nuclear estrophilins.

Animals↗
PubMed1983

Alpha-fetoprotein serum levels and the development of estrogen-sensitive cell multiplication in the hamster uterus.

Subcutaneous injections of 5 or 25 micrograms estradiol-17 beta (E2)/kg in ovariectomized adult hamsters produced substantial increases in uterine wet weight, protein content and the mitotic indices of the glandular and luminal epithelia. However, no significant increase was seen in total uterine DNA. Intact hamsters from 2 to 25 days of age received a daily subcutaneous injection of 5 micrograms E2/kg for 2 consecutive days. Significant increases in uterine wet weight and protein content first occurred at 8 and 17 days, respectively. No significant increase was observed in uterine DNA. In a separate experiment, hamsters between 2 and 20 days of age received one subcutaneous injection of 5 micrograms E2/kg. Mitotic indices in the stroma were increased at 6 and 10 days of age. Mitotic indices in the luminal epithelium were significantly increased only at 6 days of age. Rocket immunoelectrophoresis revealed a sharp decline in serum alpha-fetoprotein (AFP) concentrations after 2 days of age. Estradiol concentrations in the sera of immature hamsters gradually decreased from 55 pg/ml at 0 days of age to 17 pg/ml at 20 days of age. These results provide a quantitative analysis of the effects of E2 upon cell proliferation in the hamster uterus. The correlation of declining AFP levels and the incipience of the mitotic response to estrogen suggests that AFP may directly inhibit estrogen-sensitive cell multiplication in the neonate. Other possible causes for the lack of a mitotic response in the uterus of the newborn hamster to the administration of E2 are also discussed.

Animals↗
PubMed1983

[Concentrations of estradiol in the quail magnum during sexual development. Relation to the levels of cytoplasmic receptors for this hormone].

Estradiol 17 beta concentration and cytoplasmic estradiol binding sites were determined in the magnum of immature and developing female Quail. In the immature magnum, estradiol concentration per gram of tissue was 26 times higher than in the plasma. Early sexual development was correlated with an increase in plasma and magnum concentrations of estradiol and of cytoplasmic binding sites in the magnum. However, the ratio of binding sites concentration to that of intra-tissue of estradiol, and the intracellular distribution of estradiol (cytoplasm versus nucleus) were similar in immature and developing Quail. The results indicate that the presence of estradiol and of binding sites in the target cells of the magnum are not sufficient to induce cell proliferation.

Animals↗
PubMed1982

[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↗
PubMed1982

Early variations of blood plasma gamma-glutamyl transferase in newborn calves--a test of colostrum intake.

Fourteen newborn calves had low gamma-glutamyl transferase catalytic activity concentration in blood plasma (10 to 31 U/liter). Colostrum intake induced a dramatic increase of plasma gamma-glutamyl transferase activity, which was maximal on the 1st or 2nd day (370 to 5000 U/liter) after birth; then plasma enzyme activity slowly decreased and was stable about 100 U/liter on the 20th day. In two calves given either boiled or synthetic milk, plasma gamma-glutamyl transferase activity was not higher than 25 U/liter. Gamma-glutamyl transferase activity of blood plasma in newborn calves is an easy and inexpensive test of colostrum intake.

Animals↗
PubMed1981

[Rapid induction of hepatic acetyl-CoA carboxylase activity after estradiol benzoate injection in the quail].

The time course of hepatic Acetyl-CoA carboxylase activity as well as hepatic and plasmatic fatty acids concentrations following a single injection of estradiol benzoate (EB, 0.2 mg/kg) was studied in the quail. Acetyl-CoA carboxylase activity increases rapidly and reaches its peak 3 h after the injection of EB. Similarly, hepatic and plasmatic fatty acids concentrations are significantly increased 6 h after the hormonal injection and attain their highest level 18 h later. These results suggest that estrogen affects the hepatic fatty acids biosynthesis by regulating the conversion of acetyl-CoA to malonyl-CoA.

Acetyl Coenzyme A↗
PubMed1979

[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↗
PubMed1978

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↗
PubMed1976

[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↗