scholarly journals The relationship between spatial patterns of calcium waves and localization of Inositol 1,4,5-triphosphate receptor in rat hepatocytes

1999 ◽  
Vol 79 ◽  
pp. 152
Author(s):  
Rie Shibayama ◽  
Toru Kawanishi ◽  
Takao Hayakawa
1989 ◽  
Vol 257 (2) ◽  
pp. C347-C354 ◽  
Author(s):  
G. J. Gores ◽  
C. E. Flarsheim ◽  
T. L. Dawson ◽  
A. L. Nieminen ◽  
B. Herman ◽  
...  

In rat hepatocytes, we examined the relationship between cell volume, bleb formation, and loss of cell viability during chemical hypoxia with KCN plus iodoacetic acid. In hypotonic media (150-200 mosmol/kgH2O), cells swelled to a greater extent during chemical hypoxia than in isotonic media, but rates of cell killing were identical. Sucrose (300 mM) added to isotonic media prevented early cell swelling but actually accelerated cell killing. In contrast, mannitol (300 mM) improved cell survival but did not prevent cell swelling. Bleb formation occurred regardless of buffer tonicity. The antioxidants desferrioxamine and cyanidanol but not superoxide dismutase +/- catalase delayed lethal cell injury. Cell killing was greater during aerobic compared with anaerobic chemical hypoxia. Hydroperoxide formation was measured using a dichlorofluorescin assay and was accelerated during aerobic but not anaerobic chemical hypoxia. The results indicate that cell swelling is not the driving force for bleb formation or lethal cell injury. We conclude that “reductive stress” caused by respiratory inhibition favors formation of toxic oxygen species and may contribute to lethal cell injury during intermittent or incomplete oxygen deprivation.


1996 ◽  
Vol 71 ◽  
pp. 164
Author(s):  
Toru KAWANISHI ◽  
Satoru ISHIZAKI ◽  
Takehito KIUCHI ◽  
Miyako OHTA ◽  
Hisayuki OHATA ◽  
...  

1984 ◽  
Vol 223 (1) ◽  
pp. 39-46 ◽  
Author(s):  
D C DeSante ◽  
L Little ◽  
D E Peavy ◽  
F Vinicor

An improved non-perfusion method for the preparation of cultured foetal-rat hepatocytes is described. Digestion of the liver with collagenase and deoxyribonuclease I gave yields of 40 × 10(6) hepatocytes/g of liver. The plating efficiency of hepatocytes in medium with 10 microM-cortisol was 50%. Cell morphology and metabolism were maintained through 3 days of monolayer culture, with minimal contamination by haematopoietic cells or fibroblasts. The cultured cells bound and degraded 125I-insulin in a time- and dose-dependent manner. The estimated ED50 for competitive binding at 37 degrees C was 1.1 nM. Curvilinear Scatchard plots were observed, with estimates of 16 500 high-affinity sites (Kd = 813 pM) and 53 000 low-affinity sites (Kd = 23 nM) per cell. The cultured cells demonstrated a glycogenic response to insulin, with an estimated ED50 of 120 pM. The degree of glycogenic response to insulin varied with time in culture: 500% above basal on day 1, 200% on day 2, and only 150% on day 3. Cultured foetal cells also exhibited a time-dependent uptake of 2-aminoisobutyric acid, which, in contrast with previous reports with adult cells, was not stimulated by the presence of 10 nM-insulin. Cultured foetal hepatocytes may provide an interesting model with which to study the relationship between insulin-receptor binding and insulin action.


2002 ◽  
Vol 32 (11) ◽  
pp. 1984-1991 ◽  
Author(s):  
Michael A Battaglia ◽  
Pu Mou ◽  
Brian Palik ◽  
Robert J Mitchell

Spatial aggregation of forest structure strongly regulates understory light and its spatial variation in longleaf pine (Pinus palustris Mill.) forest ecosystems. Previous studies have demonstrated that light availability strongly influences longleaf pine seedling growth. In this study, the relationship between spatial structure of a longleaf pine forest and spatial pattern of understory light availability were investigated by comparing three retention harvest treatments: single-tree, small-group, large-group, and an uncut control. The harvests retained similar residual basal area but the spatial patterns of the residual trees differed. Hemispherical photographs were taken at 300 stations to calculate gap light index (GLI), an estimate of understory light availability. Stand-level mean, variation, and spatial distribution of GLI were determined for each treatment. By aggregating residual trees, stand mean GLI increased by 20%, as well as its spatial variation. Spatial autocorrelation of GLI increased as the size of the canopy gaps increased and the gaps were better defined; thus, the predictability of GLI was enhanced. The ranges of detrended semivariograms were increased from the control to the large-group harvest indicating the spatial patterns of understory GLI became coarser textured. Our results demonstrated that aggregated canopy structure of longleaf pine forest will facilitate longleaf pine seedling regeneration.


2013 ◽  
Vol 4 (3) ◽  
pp. 80-100 ◽  
Author(s):  
Wei Song ◽  
Daqian Liu

Urban crime has increasingly become a major issue for Chinese cities. Using crime data collected at police precincts in 2008, the main aim of this research is to examine the spatial distribution of property crime which accounted for almost 82% of all crimes in the city of Changchun, and analyze the relationship between the spatial patterns of property crime and neighborhood characteristics. Standardized property crime rates (SCR) were applied to assess the relative risk of property crime across the city. Statistically significant clusters of high-risk areas or hot-spots were detected. A global ordinary least squares (OLS) regression model and a geographically weighted regression (GWR) model were calibrated to explore the risk of property crime as a function of contextual neighborhood characteristics. The analytical results show that significant local variations exist in the relationship between the risk of property crime and several neighborhood socioeconomic variables.


Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2162 ◽  
Author(s):  
Chunhuan Jin ◽  
Zijun Wu ◽  
Lili Wang ◽  
Yoshikatsu Kanai ◽  
Xin He

Celastrol and triptolide, as the two main bio-activity ingredients in Tripterygium wilfordii, have wide anticancer pharmacological potency, as well as anti-inflammatory and immunosuppression effects. However, they have potential hepatotoxicity and underlying mechanisms of them-induced toxicity mediated by hepatic CYP450s have not been well delineated. In the present study, we accessed the toxic effects and possible mechanism of celastrol and triptolide on primary rat hepatocytes. Models of subdued/enhanced activity of CYP450 enzymes in primary rat hepatocytes were also constructed to evaluate the relationship between the two ingredients and CYP450s. LC-MS/MS was used to establish a detection method of the amount of triptolide in rat hepatocytes. As the results, cell viability, biochemical index, and mitochondrial membrane potential indicated that celastrol and triptolide had toxic potencies on hepatocytes. Moreover, the toxic effects were enhanced when the compounds combined with 1-aminobenzotriazole (enzyme inhibitor) while they were mitigated when combined with phenobarbital (an enzyme inducer). Meanwhile, celastrol could affect the amount of triptolide in the cell. We therefore put forward that increase of triptolide in the cell might be one of the main causes of hepatotoxicity caused by Tripterygium wilfordii.


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