Effect of hypoxia on glycolysis in isolated fetal rat heart]

Glycolysis was assessed in the isolated foetal Rat in hypoxia. Measurements were made of glucose uptake, lactate output, C14 glucose incorporation into glycogen and tissular levels of ATP, PCr, glycogen and lactate. Glycolysis was stimulated by hypoxia to a greater extent in the young foetal heart of 16.5 days post coitum than in the foetal heart at term. Thus high energy phosphates were maintained at a higher level in the younger heart. The results are discussed in relation to the high resistance to hypoxia of the foetal heart.     

Purification of the cytosol oestradiol-receptor complex from foetal guinea-pig uterus using electrofocusing on polyacrylamide plates

Summary The³H-oestradiol receptor complex obtained from the cytosol fraction of foetal guinea-pig uterus was purified by the following steps: column chromatography in Sephadex G-15 and Ultrogel, and by electrofocusing on polyacrylamide plates. In the final step a concentration of 15–17% of the foetal uterine oestradiol receptor protein was obtained. The isoelectric point (pl) of this receptor was determined to be 6.1–6.2.The expenses of the investigation were partially defrayed by a grant from the Centre National de la Recherche Scientifique (CNRS), France (Equipe de Recherche CNRS No. 187).     

Evolution of myocardial glycolysis in perinatal rats]

Glycolysis was assessed in the Langendorff perfused rat heart during the perinatal period. Glucose uptake, lactate production, 14C-glucose incorporation into glycogen, tissue content content of glycogen, lactate and high energy phosphates were measured in the foetus of 21.5 days post co?tum and in the newborn of 1 and 7 days post partum. Glycogen synthesis and anaerobic glycolysis were found to be more active in the foetal heart and to decrease during the first neonatal week.     

Uptake of noradrenaline in high altitude native's heart

Summary Uptake of³H-noradrenaline by the heart was studied with sections of isolated atria obtained from high or lowlanders. In native highlanders, affinity for³H-noradrenaline by human atria is more significant than in lowlanders. Furthermore, the Michaelis Menten constant is lower in high altitude native's heart.     

Stimulation of the incorporation of3H-leucine into proteins by oestradiol in the foetal uterus of the guinea-pig

Summary Oestradiol treatment increases the incorporation of³H-leucine into acid insoluble proteins in the foetal guineapig uterus (50–65 days of gestation) 10 times above control values by 8 h and 20 times by 24 h after administration of oestradiol to the mother.     

Essai d'identification des corticostéroïdes sécrétés par la surrénale embryonnaire de Veau cultivée in vitro

Summary Pieces of foetal bovine adrenals were cultured in vitro in the presence of¹⁴C-1 sodium acetate. The following radioactive corticosteroids were sought: aldosterone, cortisone, hydrocortisone, corticosterone, 11-dehydrocorticosterone, 11-deoxycorticosterone and 11-deoxy-17-hydroxycorticosterone. Four of them have been identified by thin-layer radiochromatography and derivative formation, i.e. hydrocortisone, corticosterone, 11-dehydrocorticosterone and 11-deoxycorticosterone.     

Dauerüberwachung der fetalen Herzaktionen unter der Geburt mittels Ultraschall

Summary The report concerns a new method for continuous observation of foetal heart frequency during delivery. The apparatus uses ultrasonic energy according to the Doppler-effect. The equipment is compact, reliable and relatively inexpensive. The ultrasonic energy used, is far below the intensities required to produce harmful effects in biological structures.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft und der Paul-Martini-Stiftung der Medizinisch-pharmazeutischen Studiengesellschaft e.V. Frankfurt a. M.     

Aldose metabolism in developing human fetal brain and liver

Aldose reductase, sorbitol dehydrogenase, and glucose-6-phosphate dehydrogenase enzyme activities were studied in human foetal brain and liver at different periods of gestation. Aldose reductase activity in liver disappears after 16 weeks of gestation whereas sorbitol dehydrogenase keeps on increasing in liver as well as in brain. In utero, some glucose metabolism may be mediated through an active sorbitol pathway in human fetuses.     

Kinetics of insulin secretion in response to glucose by isolated islands of Langerhans from the fetal rat]

Isolated islets of Langerhans from 21.5 day-old foetal Rats were studied in a perifusion system in vitro. The overall dynamics of insulin release by the foetal islets in response to glucose 13.9 mM is biphasic and qualitatively similar to that obtained with islets of adult Rats. The magnitude of the initial phase of insulin secretion is similar for the foetal and adult islets. The second phase is fourfold higher in the adult than in the foetus. The response of foetal islets occurs, 45 to 60 sec. after the increase of glucose concentration in the medium and a maximum insulin release for the first phase is obtained with a lag period of 2 min. The difference between foetal and adult islets is essentially quantitative.     

Newly synthesized elastin is associated with neoplastic epithelial cells in human mammary carcinoma

Summary Indirect immunofluorescence with a purified antiserum to human foetal elastin has identified newly synthesized elastin on the membranes of neoplastic epithelial cells in human mammary carcinoma.This research was supported by a project grant from the Medical Research Council, London.     

Aldose metabolism in developing human fetal brain and liver

Summary Aldose reductase, sorbitol dehydrogenase, and glucose-6-phosphate dehydrogenase enzyme activities were studied in human foetal brain and liver at different periods of gestation. Aldose reductase activity in liver disappears after 16 weeks of gestation whereas sorbitol dehydrogenase keeps on increasing in liver as well as in brain. In utero, some glucose metabolism may be mediated through an active sorbitol pathway in human fetuses.Acknowledgments. These studies were supported by the Indian Council of Medical Research.     

Unstable L-forms of micrococci in human foetal blood

Summary In human foetal blood the presence of Micrococcaceae in the unstable L-form, probably taking origin from the placental transmission of minimal reproductive units, has been recognized by means of microscopic and cultural methods.     

Follicles development in the foetal human ovary.

In the foetal human ovary, diameters of oocyte and follicle, as well as those of oocyte and nucleus, are found to be positively and linearly correlated with each other. Follicle diameter and number of granulosa cells also show a positive and linear relationship. Finally, in all ovaries examined, from 5 months after conception onwards, small antral follicles were assessed.     

Follicles development in the foetal human ovary

Summary In the foetal human ovary, diameters of oocyte and follicle, as well as those of oocyte and nucleus, are found to be positively and linearly correlated with each other. Follicle diameter and number of granulosa cells also show a positive and linear relationship. Finally, in all ovaries examined, from 5 months after conception onwards, small antral follicles were assessed.     

sRNA methylase activity of embryonic liver

Résumé Utilisant SAM-¹⁴CH₃ il a été démontré que le foie foetal a plus d'activité de sRNA methylase que le foie adulte.

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This investigation was supported in part by an allocation from a Public Health Service General Research Support Grant No. SO 1 FR-05545-03, and an American Cancer Society Grant No. IN 19F to The Jackson Laboratory, Bar Harbor, Maine, and by Public Health Service Research Grants No. HD-01496 from the National Institute of Child Health and Human Development and No. FR-00251 from the Division of Research Facilities and Resources.     

Effect of X-irradiation on phosphorylase activity in tissues of pregnant mice

Résumé Les niveaux de phosphorylase du foie et du placenta maternels oscillent, mais chez les souris, ceux du foie foetal augmentent constamment pendant la grossesse. L'effet des rayons X sur la phosphorylase du foie foetal est relativement plus élevé.     

Endogenous oscillatory activity and TTX-sensitive spikes of the heart muscle in early juveniles of the isopod crustaceanLigia exotica

The heart beat of early juveniles of the littoral isopodLigia exotica occurred at a frequency of 250 to 350/min, associated with rhythmic activity of the heart muscle. Each burst was composed of a slow depolarizing potential with superimposed spike potentials. The spike potential was eliminated by perfusion with TTX-containing or Na⁺-free saline. In TTX-saline, the slow potential was unchanged in frequency and amplitude. By current injection into the heart muscle, the rhythm of the slow potential was phase-shifted and its frequency was changed in a membrane potential-dependent manner. These results show that the heart ofLigia early juveniles acts as an endogenous muscle oscillator generating oscillatory slow potentials and Na⁺-dependent spikes.     

Structure and function of the type 1 insulin-like growth factor receptor

The type 1 insulin-like growth factor receptor (IGF-1R), a transmembrane tyrosine kinase, is widely expressed across many cell types in foetal and postnatal tissues. Activation of the receptor following binding of the secreted growth factor ligands IGF-1 and IGF-2 elicits a repertoire of cellular responses including proliferation, and the protection of cells from programmed cell death or apoptosis. As a result, signalling through the IGF-1R is the principal pathway responsible for somatic growth in foetal mammals, whereas somatic growth in postnatal animals is achieved through the synergistic interaction of growth hormone and the IGFs. Forced overexpression of the IGF-1R results in the malignant transformation of cultured cells: conversely, downregulation of IGF-1R levels can reverse the transformed phenotype of tumour cells, and may render them sensitive to apoptosis in vivo. Elevated levels of IGF-IR are observed in a variety of human tumour types, whereas epidemiological studies implicate the IGF-1 axis as a predisposing factor in the pathogenesis of human breast and prostate cancer. The IGF-1R has thus emerged as a therapeutic target for the development of antitumour agents. Recent progress towards the elucidation of the three-dimensional structure of the extracellular domain of the IGF-1R represents an opportunity for the rational assembly of small molecule antagonists of receptor function for clinical use.     

Brain development in offspring of rats treated with nicotine during pregnancy

Résumé Lorsque le rat a été traité par des injections journalières de nicotine au cours de la gestation, le développement des réponses du jeune rat a l'électrochoc est retardé. Ce modifications, qui reflètent des altérations dans la maturation des systèmes inhibiteurs et excitants du système nerveux central au cours de la croissance persistent jusqu'à la 5^e semaine post-natale. Ces résultats indiquent que la nicotine est capable de provoquer des modifications dans le développement du cerveau à l'état foetal.     

Digoxin and ouabain increase the synthesis of cholesterol in human liver cells

Digoxin and ouabain are steroid drugs that inhibit the Na⁺/K⁺-ATPase, and are widely used in the treatment of heart diseases. They may also have additional effects, such as on metabolism of steroid hormones, although until now no evidence has been provided about the effects of these cardioactive glycosides on the synthesis of cholesterol. Here we report that digoxin and ouabain increased the synthesis of cholesterol in human liver HepG2 cells, enhancing the activity and the expression of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the rate-limiting enzyme of the cholesterol synthesis. This effect was mediated by the binding of the sterol regulatory element binding protein-2 (SREBP-2) to the HMGCR promoter, and was lost in cells silenced for SREBP-2 or loaded with increasing amounts of cholesterol. Digoxin and ouabain competed with cholesterol for binding to the SREBP-cleavage-activating protein, and are critical regulators of cholesterol synthesis in human liver cells. Received 10 January 2009; received after revision 11 February 2009; accepted 6 March 2009