Comptes rendus des seances de l'Academie des sciences. Serie III, Sciences de la vie最新文献

Effects of two halogenated acetamides (chloroacetamide-iodoacetamide) and of three chlorinated volatile solvents on the ethane-pentane test, as an index of in vivo lipid peroxidation have been studied. Chloroacetamide stimulates alcanes production. Iodoacetamide acts only on pentane exhalation. The three chlorinated solvents seem to induce moderate lipoperoxidation, and the apparent increase of hydrocarbons might also result from decreased metabolism.

Parathyroid glands from patients in chronic haemodialysis and with secondary hyperparathyroidism have been studied by electron probe X ray microanalysis and analytical ion microscopy. Aluminium associated with phosphorus has been detected in phagolysosomes of parathyroid cells (chief cells and oxyphil cells).

The analysis of acoustic signals, in the loud calls of the subadult male, with Gibbons (H. concolor gabriellae) shows several progressive modifications between the calls of the juvenile and those of the adult male. All the characteristics of antiphonal duos are not integrated at the same rate within the call of the adult male.

A molecular model is proposed for Angiotensin II which could be close to an active form. This model corresponds to a complexed conformation and agrees with many experimental results. Its conformational energy ranges around the conformations already proposed, so that complexation must highly favour it.

238U+ was detected in Mytilus edulis collected from the Pas-de-Calais and the Baie de Seine. Storage organs were mantle, digestive gland, intestine epithelium and gonad where the highest values occurred. Uranium uptake happened via gill and digestive tractus, and excretion via kidney. Hemocytes played an important part in uptake, storage and excretion of the metal. M. edulis which was shown to concentrate the radionuclide from the marine environment where the metal exists at trace level, is then proposed as an uranium pollution indicator organism.

Ultrastructural immunocytochemistry with anti-insulin antiserum allowed the detection of insulin antigenic sites localized at the inner aspect of the cisternae of the Golgi apparatus in pancreatic B-cells. By contrast, in secretory granules released from the Golgi apparatus, insulin antigenic sites were localized over the granule content but not on the membrane. The demonstration of insulin antigenic sites at the level of the Golgi membranes is compatible with the presence of specific insulin receptors and/or charge interactions between the insulin and the membrane. Binding at this level could in turn be involved in the sorting out of insulin polypeptides destined to be concentrated in secretory granules.

Xanthine oxidase activity: NAD+-dependent form (D) and O2-dependent form (O) were carried out in cytosol supernatants of connective tissue growth (T.C.N.F.), skin tail, liver and plasma of carrageenan induced granuloma in the Rat. The specific activities of skin, liver and plasma were normal in animals with a granuloma. The total specific activity (D + O): 7.53 +/- 0.98 mU/mg protein, and the percentage of form O: 51.6 +/- 5.1 of the granulomatous tissue as compared to the tail are significantly increased. These results suggest the likely function of xanthine oxidase during the inflammatory response.

The adenylate cyclase activity of Rat brain synaptosomal membranes is strongly activated by forskolin. This study demonstrates: 1. That GTP or its analogs, when added to forskolin, decrease the enzyme stimulation by a factor of 40 to 60%; 2. That Pertussis toxin (TP), in the presence of NAD, ADP-ribosylates a single membrane protein of 40,000 dalton apparent molecular weight in a strictly concomitant manner. This Lubrol-soluble protein has a sedimentation coefficient of 3.6 and a Stokes radius of 6 nm. An immune serum against TP blocks the NAD-glycohydrolase activity of the toxin.

Effect of injection of Arachis hypogea (PNA) and Soybean (SBA) lectins on the migration of Xenopus primordial germ cells (PGCs) were investigated. PNA inhibited almost entirely the PGCs migration, more than SBA. Our results indicated that the inhibition of the migration could be a consequence of the lectin-induced alterations of cell surface properties.