0000000000117892
AUTHOR
Prudent Padieu
Metformin induces an agonist-specific increase in albumin production by primary cultured rat hepatocytes
Abstract Metformin (MET) is known to increase several biological effects of insulin (INS), but there is no information concerning its direct effects on protein synthesis. We studied the action of MET on albumin production by primary cultures of freshly isolated rat hepatocytes, alone or in combination with various agonists: INS, IGF-1, EGF, thyroxin, and dexamethasone. While having no effect alone, MET in vitro potentiates the effects of INS, IGF-1, and EGF. When this increasing effect toward INS was studied over a broad concentration range, MET appeared to improve low-acting INS levels and to intensify the maximal INS effects. In contrast, MET did not change the production of albumin stimu…
The lipoprotein lipase activity in cultured beating heart cells of the post-natal rat.
Summary The lipoprotein lipase (LPL) activity was studied in cultured beating heart cells of the post natal rat as a function of the culture age, from the freshly trypsinized cell suspension up to the 14th day of culture. The LPL activity remains at a practically stationary level during the first four days of culture, and then increases rapidly to reach a plateau, at a level 3–4 times higher at the 21th day of culturing. The significance of this enzymatic activity progression comparing to 3H thymidine incorporation from the point of view of cell differentiation is discussed. Our results suggest that after the 12th day of culture, cells contain their optimal enzymatic apparatus for lipid met…
Transfection of lipoma cells with papilloma bovine virus subgenomic fragment.
Abstract Lipoma cells with consistent chromosomal aberration have been transfected with plasmids carrying papilloma bovine virus subgenomic fragment (PBV 69). The succesful transformation of the cells was ascerted on the changed growth pattern of the cells in liquid medium, colony formation in soft agar and modified cell appearrance in electron microscopy; transfection with PBV 69 has not been, however, sufficient to immortalize lipoma cells.
Synthesis and gas chromatographic-mass spectrometric analysis of reduced compounds derived from 6 alpha- and 6 beta-hydroxy-11-deoxycorticosterone.
Abstract A series of thirty two 6-hydroxylated steroids were synthesized by selective reduction of the 4–5 double bond, the 3-oxo group, and/or the 20-oxo group of 6α- and 6β-hydroxyDOC. The different reactions leading to the production of specific isomers are discussed. The gas chromatographic and spectrometric characteristics of the methoxime-trimethylsilyl (MO-TMS) or trimethylsilyl (TMS) derivatives of the isomers obtained are given. The gas chromatographic separation of the syn- and anti -isomers of the methoxime in position 3 was found to be characteristic of the configuration of the hydroxyl in position 6. The difference between methylene unit values of syn- and anti- isomers is much…