The in vitro metabolism of estrone and estradiol-17 beta and their 3-sulfates by the renal tissues from pregnant and female fetal guinea-pigs.
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Animals↗
Biomedical subjects
G L Adessi
Publications and source records attributed to G L Adessi.
A comparison of the in vitro metabolism of estrone, estradiol-17 beta and estrone-3-sulfate by the livers of young virgin female, pregnant and female fetal guinea-pigs.
The metabolism, in vitro, of [3H]-estrone, [3H]-estradiol-17 beta and [13H]-estrone-3-sulfate by the livers of pregnant, young virgin female and female fetus guinea-pigs has been compared using 900 g supernatants and microsomes. The ability of the guinea-pig livers to synthesize polyhydroxylated estrogens has been fo-nd to be small. The major metabolites isolated were unconjugated estrone and estradiol-17 beta or their glucuronides. The percentage of sulfates was lower after incubations with [3H]-estrone than with [3H]-estradiol-17 beta. A kinetic study with microsomes has shown a direct conversin of estrone-sulfate to estradiol sulfate. Fetal microsomes have been found to exhibit a more active hydrogenation of estrone to estradiol-17 beta than microsomes from young female or pregnant animals.
Animals↗
Conversion, in vitro, of (7n-3H) testosterone to estrone and estradiol-17beta and their 3-sulfate conjugate by the guinea-pig placenta.
Different cellular fractions of guinea-pig placenta were incubated in the presence of (7n-3H) testosterone. Microsomal aromatization of 3H-testosterone into estrone and estradiol-17beta was demonstrated in the presence of NADPH. The predominance of estrone after incubation with 17beta-hydroxylated precursors, (7n-3H) testosterone and (6,7-3H) estradiol-17beta, indicate that there is a microsomal 17beta-hydroxysteroid dehydrogenase activity. In this report, cytosolic sulfurylation of estrogens is demonstrated. This latter activity represents a quite original characteristic of the placental metabolism of estrogens in guinea-pigs. In contrast with the human placenta where there is considerable sulfatase activity, the guinea-pig placenta can sulfurylate estrogens.
17-Hydroxysteroid Dehydrogenases↗
Gas chromatography profile of estrogens: application to pregnancy urine.
A method for the simultaneous quantitation of 7 estrogens in pregnancy urine is described. It involves enzymatic hydrolysis extraction of free steroids, ion-exchange column chromatography and quantitation of the trimethylsilyl derivatives by gas chromatography on OV 1. Data obtained from normal and twin pregnancies and from women with anencephalic fetus or intra uterine fetal death are analysed. The sensibility of the method is about 40 mug of each estrogen by liter of urine.
Chromatography, Gas↗
Lack of correlation between steroid sulfatase activities and lipid content in uterus and liver microsomes of guinea pigs.
Lipid content and steroid sulfatase activities were determined in liver and uterus microsomes of non-pregnant guinea pigs. The results were compared with values obtained in pregnant and cortisol-treated animals. Steroid sulfatase activities were always higher in pregnant animals, and we supposed that the increase in circulating cortisol in pregnant guinea pigs before parturition has an influence on the membrane-bound sulfatase activities. Sulfatase activities were identical in cortisol-treated and untreated non-pregnant females, although cortisol induced changes in microsomal lipid composition. These results lead us to three conclusions: in intact female guinea pigs, cortisol induces variations in the lipid content of uterus and liver microsomes, especially in the cholesteryl sulfate to phospholipid ratios; the variations of the lipid composition in pregnant animals do not appear to be cortisol-dependent; membrane-bound steroid sulfatase activities are not directly influenced by the lipid composition of microsomes.
Animals↗
Influence of cigarette smoking on P53 gene mutations in bladder carcinomas.
BACKGROUND: The aim of this study was to analyse the influence of cigarette smoking on bladder carcinomas. PATIENTS AND METHODS: 98 cases of bladder cancers were examined by single strand conformation polymorphism analysis of exons 5 to 9, followed by DNA direct sequencing. RESULTS: The incidence of p53 gene mutations was not significantly influenced by habitual smoking. However, the p53 mutation spectrum of current smokers differed significantly from the pattern for non-smokers and ex-smokers. Differences between the two populations included multiple mutations in the current-smokers and an absence in non- and ex-smokers (p<0.01), with the predominance of G:C to A:T transitions at CpG sites in non-smokers (60.0%) in comparison with current smokers (7.6%) (p<0.02). Moreover, G:C to T:A and G:C to C:G transversions were found solely in current smokers. CONCLUSION: It would appear that, in current-smokers, the spectrum of p53 gene mutations is related to tobacco-smoke carcinogens and that the habit of smoking increases the extent of DNA damage.
Aged↗
Human breast cancer: correlation study between HER-2/neu amplification and prognostic factors in an unselected population.
In 199 breast cancers, HER-2/neu amplification was analyzed by Southern blotting (149 cases) and by slot blotting (149 cases), with 99 cases studied using both techniques. There were 18.8% amplified tumors (> or = 2 copies) by Southern blotting and 15.4% by slot blotting. The difference in the percentages of amplified tumors was not statistically significant (p = 0.44). There was a correlation between HER-2/neu amplification and the SBR grade (p = 0.046): this correlation relied on the absence of amplification in the GI tumors. In a subset study, the negativity of the progesterone receptor content was correlated with HER-2/neu amplification in the node positive (p = 0.02), the pre-menopausal (p = 0.04) and the pre-menopausal node positive (p = 0.002) patients. In the literature as in our results, amplification appears to be correlated with poor prognostic factors. However, in a subgroup with most of the favorable prognostic factors: positive estrogen and progesterone receptor contents and node negativity, the frequency of amplified tumors (19.4%, n = 67) was the same as that observed in the whole group (16.6%, n = 199). This result may suggest that the HER-2/neu amplification could act as an independent prognostic factor.
Adult↗
Differential EGF action on nuclear protooncogenes in human endometrial carcinoma RL95-2 cells.
Our aim was to analyze EGF action on nuclear protooncogenes in RL95-2 since it has not been documented so far. Synchronization and partial' growth arrest were obtained by maintaining cells for 15 hours in L-methionine-free medium. After this depletion, EGF transiently increased fos and jun mRNAs: the expression peaked at 45 minutes for c-fos (5.5 fold induction) and at 60 minutes for c-jun and jun-B (3 fold induction) and the mRNA levels returned to the basal value within 3 hours. Upon EGF addition, c-myc mRNAs peaked at 12 hours (7.6 fold induction) and surprisingly remained higher than the control up to 48 hours. Unlike fetal calf serum, EGF did not increase the cell number and this could be linked to steadily induced c-myc expression. These data provide evidence for a differential EGF action on fos/jun and c-myc in RL95-2 cells.
Cell Cycle↗