The in vivo calcium status significantly perturbes both the 6Ca2+9i and regenerative signals of rat hepatocytes

Hepatology ◽  
1993 ◽  
Vol 18 (4) ◽  
pp. A184
Author(s):  
M GASCONBARRE
2019 ◽  
Vol 15 (7) ◽  
pp. 771-780
Author(s):  
He-Min Li ◽  
Ting Gu ◽  
Wen-Yu Wu ◽  
Shao-Peng Yu ◽  
Tian-Yuan Fan ◽  
...  

Background: Exogenous antioxidants are considered as a promising therapeutic approach to treat neurodegenerative diseases since they could prevent and/or minimize the neuronal damage by oxidation. Objective: Three series of lipophilic compounds structurally based on scutellarein (2), which is one metabolite of scutellarin (1) in vivo, have been designed and synthesized. Methods: Their antioxidant activity was evaluated by detecting the 2-thiobarbituric acid reactive substance (TBARS) produced in the ferrous salt/ascorbate-induced autoxidation of lipids, which were present in microsomal membranes of rat hepatocytes. The lipophilicity of these compounds indicated as partition coefficient between n-octanol and buffer was investigated by ultraviolet (UV) spectrophotometer. Results: This study indicated that compound 5e which had a benzyl group substituted at the C4'- OH position showed a potent antioxidant activity and good lipophilicity. Conclusion: 5e could be an effective candidate for preventing or reducing the oxidative status associated with the neurodegenerative processes.


1997 ◽  
Vol 6 (4) ◽  
pp. 377-386 ◽  
Author(s):  
Sanjeev Gupta ◽  
Srinivasa Rao G. Vasa ◽  
Pankaj Rajvanshi ◽  
Lionel S. Zuckier ◽  
Christopher J. Palestro ◽  
...  

Knowledge of the kinetics of cell distribution in vascular beds will help optimize engraftment of transplanted hepatocytes. To noninvasively localize transplanted cells in vivo, we developed conditions for labeling rat hepatocytes with 99mTc–pertechnetate. The incorporated 99mTc was bound to intracellular proteins and did not impair cell viability. When 99mTc hepatocytes were intrasplenically injected into normal rats, cells entered liver sinusoids with time–activity curves demonstrating instantaneous cell translocations. 99mTc activity in removed organs was in liver or spleen, and lungs showed little activity. However, when cells were intrasplenically transplanted into rats with portasystemic collaterals, 99mTc appeared in both liver sinusoids and pulmonary alveolar capillaries. To further localize cells, we transplanted DPPIV+ F344 rat hepatocytes into syngeneic DPPIV – recipients. Histochemical staining for DPPIV activity demonstrated engraftment of intrasplenically transplanted cells in liver parenchyma. In contrast, when 99mTc hepatocytes were injected into a peripheral vein, cells were entrapped in pulmonary capillaries but were subsequently broken down with redistribution of 99mTc activity elsewhere. Intact DPPIV+ hepatocytes were identified in lungs, whereas only cell fragments were present in liver, spleen, or kidneys. These findings indicate that although the pulmonary vascular bed offers advantages of easy accessibility and a relatively large capacity, significant early cell destruction is an important limitation.


1997 ◽  
Vol 41 (11) ◽  
pp. 2502-2510 ◽  
Author(s):  
X R Pan-Zhou ◽  
E Cretton-Scott ◽  
X J Zhou ◽  
M Y Xie ◽  
R Rahmani ◽  
...  

AZT-P-ddI is an antiviral heterodimer composed of one molecule of 3'-azido-3'-deoxythymidine (AZT) and one molecule of 2',3'-dideoxyinosine (ddI) linked through their 5' positions by a phosphate bond. The metabolic fate of the dimer was studied with isolated rat, monkey, and human hepatocytes and was compared with that of its component monomers AZT and ddI. Upon incubation of double-labeled [14C]AZT-P-[3H]ddI in freshly isolated rat hepatocytes in suspension at a final concentration of 10 microM, the dimer was taken up intact by cells and then rapidly cleaved to AZT, AZT monophosphate, ddI, and ddI monophosphate. AZT and ddI so formed were then subject to their respective catabolisms. High-performance liquid chromatography analyses of the extracellular medium and cell extracts revealed the presence of unchanged dimer, AZT, 3'-azido-3'-deoxy-5'-beta-D-glucopyranosylthymidine (GAZT), 3'-amino-3'-deoxythymidine (AMT), ddI, and a previously unrecognized derivative of the dideoxyribose moiety of ddI, designated ddI-M. Trace extracellular but substantial intracellular levels of the glucuronide derivative of AMT (3'-amino-3'-deoxy-5'-beta-D-glucopyranosylthymidine [GAMT]) were also detected. Moreover, the extent of the formation of AMT, GAZT, and ddI-M from the dimer was markedly lower than that with AZT and ddI alone by the hepatocytes. With hepatocytes in primary culture obtained from rat, monkey, and human, large interspecies variations in the metabolism of AZT-P-ddI were observed. While GAZT and ddI-M, metabolites of AZT and ddI, respectively, as well as AZT 5'-monophosphate (MP) and ddI-MP were detected in the extracellular media of all species, AMT and GAMT were produced only by rat and monkey hepatocytes. No such metabolites were formed by human hepatocytes. The metabolic fate of the dimer by human hepatocytes was consistent with in vivo data recently obtained from human immunodeficiency virus-infected patients.


2001 ◽  
Vol 10 (3) ◽  
pp. 329-342 ◽  
Author(s):  
Emmanouhl S. Tzanakakis ◽  
Chang-Chun Hsiao ◽  
Taku Matsushita ◽  
Rory P. Remmel ◽  
Wei-Shou Hu

Cytochrome P450 (CYP450) enzymes are essential for xenobiotic metabolism. Although CYP450s are found in many tissues, CYP2B1/2 are primarily expressed in the rat liver. The constitutive expression in vivo of CYP2B1/2 is low but it is induced in the presence of various drugs such as phenobarbital (PB). In this study, CYP2B1/2 activity in cultured hepatocytes was assessed in situ with the introduction of a fluorogenic sub-strate, pentoxyresorufin. The product of 7-pentoxyresorufin-O-dealkylation (PROD), which is catalyzed specifically by CYP2B1/2, was detected using confocal laser scanning microscopy (CLSM). Primary hepatocytes cultured as monolayers on collagen-coated surfaces exhibited background PROD activity and minimal PB inducibility after 4 days in culture. In contrast, rat hepatocytes organized in compacted aggregates, or spheroids, exhibited higher levels of PROD activity and retained their ability for PB induction. The results from the CLSM analysis were verified by RT-PCR and Western immunoblotting analysis. Furthermore, CLSM in conjunction with image processing techniques and three-dimensional reconstruction revealed the localization of enhanced PROD activity in the center of spheroids. The results support the use of CLSM as a powerful tool for investigating CYP2B1/2 activity in cultured rat hepatocytes.


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