Rolf Gebhardt

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In order to contribute to the elucidation of the function of astrocyte glycogen in brain, studies on the fate of the glucosyl residues of glycogen were carried out on astroglia-rich primary cultures derived from the brains of newborn rats. On glucose deprivation astroglial cells rapidly deplete their glycogen. In contrast to the situation with hepatocytes,(More)
This review encompasses the most important advances in liver functions and hepatotoxicity and analyzes which mechanisms can be studied in vitro. In a complex architecture of nested, zonated lobules, the liver consists of approximately 80 % hepatocytes and 20 % non-parenchymal cells, the latter being involved in a secondary phase that may dramatically(More)
Liver parenchyma shows a remarkable heterogeneity of the hepatocytes along the porto-central axis with respect to ultrastructure and enzyme activities resulting in different cellular functions within different zones of the liver lobuli. According to the concept of metabolic zonation, the spatial organization of the various metabolic pathways and functions(More)
Only little is known about how cells coordinately behave to establish functional tissue structure and restore microarchitecture during regeneration. Research in this field is hampered by a lack of techniques that allow quantification of tissue architecture and its development. To bridge this gap, we have established a procedure based on confocal laser(More)
The distribution of glutamine synthetase [L-glutamate: ammonia ligase (ADP-forming), EC 6.3.1.1)] among rat liver parenchymal cells in situ and in primary culture was investigated by indirect immunofluorescence using a specific antiserum. In intact liver, the enzyme was found to be localized exclusively within a very small population of the parenchymal(More)
Aberrant Wnt-signaling caused by mutants of β-catenin, a key regulator of the canonical Wnt-signaling pathway, is frequently detected in cancer. Only recently, it was suggested that in hepatocellular carcinoma (HCC) the expression of the target gene glutamine synthetase (GS) is a highly reliable marker for the identification of β-catenin mutations. In order(More)
Primary hepatocytes represent a well-accepted in vitro cell culture system for studies of drug metabolism, enzyme induction, transplantation, viral hepatitis, and hepatocyte regeneration. Recently, a multicentric research program has been initiated to optimize and standardize new in vitro systems with hepatocytes. In this article, we discuss five of these(More)
  • Rolf Gebhardt
  • Medical science monitor : international medical…
  • 2001
It is well known that water-soluble extracts of artichoke (Cynara scolymus L.) leaves exert choleresis. When studying this effect in vitro using primary cultured rat hepatocytes and cholephilic fluorescent compounds, it was noticed that the artichoke leaf extracts not only stimulated biliary secretion, but that they also reestablished it when secretion was(More)
Based on the tetracycline-regulated gene expression system, a double-transgenic mouse model for liver fibrosis was established in which the expression of transforming growth factor beta1 (TGF-beta1) can be regulated deliberately by addition or removal of doxycycline hydrochloride to the drinking water. TGF-beta1 plasma levels in induced double-transgenic(More)