scholarly journals The Effect of Oleic and Palmitic Acid on Induction of Steatosis and Cytotoxicity on Rat Hepatocytes in Primary Culture

2015 ◽  
pp. S627-S636 ◽  
Author(s):  
A. MORAVCOVÁ ◽  
Z. ČERVINKOVÁ ◽  
O. KUČERA ◽  
V. MEZERA ◽  
D. RYCHTRMOC ◽  
...  

In vitro models serve as a tool for studies of steatosis. Palmitic and oleic acids can induce steatosis in cultured hepatocytes. The aim of our study was to verify steatogenic and cytotoxic effects of palmitic acid (PA), oleic acid (OA) and their combinations as well as their impact on functional capacity of rat primary hepatocytes. Hepatocytes were exposed to OA or PA (0.125-2 mmol/l) or their combination at ratios of 3:1, 2:1 or 1:1 at the final concentrations of 0.5-1 mmol/l. Both OA and PA caused a dose-dependent increase in triacylglycerol content in hepatocytes. PA was more steatogenic at 0.25 and 0.5 mmol/l while OA at 0.75 and 1 mmol/l. PA exhibited a dose-dependent cytotoxic effect associated with ROS production, present markers of apoptosis and necrosis and a decrease in albumin production. OA induced a damage of the cytoplasmic membrane from 1 mM concentration. Mixture of OA and PA induced lower cytotoxicity with less weakened functional capacity than did PA alone. Extent of steatosis was comparable to that after exposure to OA alone. In conclusion, OA or combination of OA with PA is more suitable for simulation of simple steatosis than PA alone.

2006 ◽  
Vol 49 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Otto Kučera ◽  
Halka Lotková ◽  
Roman Kanďár ◽  
Renata Héžová ◽  
Vladimíra Mužáková ◽  
...  

D-galactosamine (GalN) is a highly selective hepatotoxin that causes liver damage similar to human viral hepatitis via depletion of uridine nucleotides, which subsequently diminishes synthesis of RNA and proteins. Model of galactosamine hepatotoxicity is frequently used in animal experiments in vitro. The purpose of our study was to establish the model of GalN-induced hepatocyte injury in in vitro conditions using primocultures of rat hepatocytes as an important prerequisite for further experiments in which we would like to study potential hepatoprotective effect of various substances. Rate of hepatocyte injury was evaluated by morphological changes, changes in cell viability, albumin production, mitochondrial membrane potential, activity of mitochondrial dehydrogenases and glutathione content. Marked dose dependent hepatocyte injury was found after 24-hour incubation with GalN. Based on the results we suggest as an optimal model for short-term toxicity test exposure to GalN for 24 hours in dose of 40 mM.


2005 ◽  
Vol 94 (12) ◽  
pp. 1236-1244 ◽  
Author(s):  
Olav Klingenberg ◽  
Reidun Øvstebø ◽  
Gun-Britt Joø ◽  
Åse-Brit Westvik ◽  
Peter Kierulf ◽  
...  

SummaryTissue factor (TF), the main initiator of blood coagulation, contributes to the manifestation of disseminated intravascular coagulation following septic shock in meningococcal infection. Since a direct relationship between disease severity and lipopolysaccharide (LPS) concentration in the circulation has been shown, we hypothesized that the procoagulant and cytotoxic effects of endotoxin also in vitro were related to its concentration. In vitro studies, however, have frequently used much higher LPS concentrations than those observed in clinical samples. Using elutriation-purified human monocytes, we observed that LPS up to 1000 ng/ml exerted a concentration-dependent increase in TF activity (tenase activity, fibrin formation in plasma). Although there was a dose-dependent increase in TF activity, there was not a concomitant increase in TF expression at LPS concentrations above 1 ng/ml (flow cytometry, Western blotting, TF mRNA). Flow cytometry revealed that this discrepancy between TF activity and TF expression at endotoxin concentrations above 1 ng/ml, coincided with an LPS dose-dependent increase in cell surface phosphatidylserine (PS), considered to promote coagulation. The increased PS expression was associated with an increased number of 7-AAD-positive cells indicating cell death. We conclude that enhancement of monocyte procoagulant activity in vitro by high concentrations of LPS may result from increased PS exposure due to apoptosis and necrosis. Therefore, the LPS concentrations used to examine monocyte procoagulant activity in vitro, should be carefully chosen.


1988 ◽  
Vol 16 (1) ◽  
pp. 32-37
Author(s):  
Margherita Ferro ◽  
Anna Maria Bassi ◽  
Giorgio Nanni

Two hepatoma cell cultures were examined as in vitro models to be used in genotoxicity and cytotoxicity tests without the addition of bioactivating enzymes. The MH1C1, and HTC hepatoma lines were used in this study to establish their sensitivity to a number of xenobiotics, namely, cyclophosphamide (CP), the classical positive control in bioactivation tests; benzaldehyde (BA), a short-chain aldehyde; and 4-hydroxynonenal (HNE), a major toxic end-product of the peroxidative degradation of cell membrane lipids. As a first approach, we compared the following cytotoxicity tests: release of lactate dehydrogenase (LDH), and colony formation efficiency (CF). Colony-forming cells were exposed to the drugs according to different procedures, before or after the anchorage phase. The leakage of LDH into the medium following exposure of both cell lines to HNE, CP and BA for up to 24 hours was found not to be a good index of cytotoxicity. A better indicator of cytotoxicity was CF, as evaluated by exposure of the cells 24 hours after seeding. The effects were detectable at very low concentrations, corresponding to 10, 90 and 100μM for HNE, CP and BA, respectively. The impairment of CF efficiency was dose-dependent and time-dependent, and several differences between the two cell lines were observed.


1980 ◽  
Vol 239 (3) ◽  
pp. G198-G203 ◽  
Author(s):  
G. Flemstrom

An in vitro preparation of proximal duodenum from the bullfrog transported alkali into the luminal solution (approximately 1 mueq x h-1 x cm-2) and generated a transepithelial electrical potential difference (5-10 mV, lumen negative). Transport was inhibited by 2,4-dinitrophenol (10(-5) M), CN- (5 X 10(-3) M), indomethacin (5 X 10(-5) M), and acetazolamide (5 X 10(-3) M) indicating that metabolism is required. Both alkali transport and the electrical potential difference showed a dose-dependent increase on administration of the prostaglandins E2, 16,16-dimethyl E2, and F2 alpha. The minimal concentration stimulating transport was lower with the E-type prostaglandins (10(-8) M than with F2 alpha (10(-6) M), and the former also produced greater maximal responses. In addition to metabolic-dependent transport of alkali, there was passive transmucosal migration of HCO3-, amounting to approximately 40% of basal (unstimulated) transport and sensitive to variation of the transmucosal hydrostatic pressure. Morphological examination showed that the preparation is devoid of Brunner glands. Stimulation of duodenal epithelial HCO3- transport by prostaglandins may contribute to their previously demonstrated ability to prevent duodenal ulceration.


2016 ◽  
Vol 11 (4) ◽  
pp. 830 ◽  
Author(s):  
Naveed Aslam ◽  
Khalid Hussain Janbaz ◽  
Qaiser Jabeen

<p class="Abstract">In order to rationalize the traditional uses of <em>Asphodelus </em>tenuifolius in cardiovascular complaints, aqueous-ethanol extract of the plant was investigated for hypotensive and diuretic activities using <em>in vivo</em> and in vitro models. Intravenous administration of the extract in anesthetized rats produced 14.5 (95% CI; 13.3–15.6), 24.5 (95% CI; 21.3-27.9) and 35.3% (95% CI; 32.0–42.5)  fall in mean arterial blood pressure at the doses of 3, 10 and 30 mg/kg, respectively. The extract increased the urine volume and electrolytes excretion significantly at the doses of 300 and 500 mg/kg in rats. In rabbit’s isolated aorta preparations, the extract, like verapamil, relaxed K<sup>+ </sup>(80 mM)-induced contractions more potently than phenylephrine (1 µM)–induced contractions, indicating Ca<sup>2+</sup> antagonistic activity. The extract produced dose-dependent stimulant followed by depressant effects in spontaneously contracting rabbit’s paired atria preparations. The results suggest that the extract of <em>A. </em>tenuifolius has hypotensive and diuretic effects in animals.</p><p> </p>


1972 ◽  
Vol 50 (6) ◽  
pp. 476-484 ◽  
Author(s):  
H. Kalant ◽  
A. E. LeBlanc ◽  
M. Guttman ◽  
J. M. Khanna

Metronidazole, added in vitro, did not act either as an inhibitor or as a substrate for the alcohol dehydrogenase activity of rat liver homogenates. Concentration curves of ethanol and acetaldehyde in the blood after an oral dose of ethanol were not altered by pretreatment with metronidazole; in contrast, disulfiram caused marked elevation of acetaldehyde levels. When given once only, metronidazole (or possibly a metabolite of it) exerted a mild central depressant effect of its own and produced a dose-dependent increase in the intoxicant effect of ethanol. After repeated administration of metronidazole, synergism with ethanol was not seen. An incidental finding was the production of a volatile material during incubation of solutions containing NAD, which gives an acetone-like peak in gas-liquid chromatograms.


1986 ◽  
Vol 56 (1) ◽  
pp. 305-311 ◽  
Author(s):  
A. Arieli

1. Heat production rate (H) of rumen fluid was measured in a direct calorimeter, Basal H of samples of 15 ml rumen fluid mixed with 45 ml buffer was 0.4 mW/ml rumen fluid.2. Addition of glucose (0.4–6.4 mg/sample) was followed by a dose-dependent increase in H. Maximal H was 1.1 rnW/ml and lasted up to 5 min, returning thereafter to the basal level.3. Expression of fermentation heat (Hf; kJ/mol substrate added) against glucose dose indicated an asymptotic dose response.4. Maximal Hf(at infinite dilution) agreed with stoichiometric calculations whereas minimal Hfsuggested a partial fermentation of the substrate at a high-glucose dose in the rumen environment.


Development ◽  
2021 ◽  
Author(s):  
Sophie H. L. Austin ◽  
Rut Gabarró-Solanas ◽  
Piero Rigo ◽  
Oana Paun ◽  
Lachlan Harris ◽  
...  

Adult mouse hippocampal neural stem cells (NSCs) generate new neurons that integrate into existing hippocampal networks and modulate mood and memory. These NSCs are largely quiescent and are stimulated by niche signals to activate and produce neurons. Wnt/β-catenin signalling acts at different steps along the hippocampal neurogenic lineage, but whether it has a direct role in the regulation of NSCs remains unclear. Here we used Wnt/β-catenin reporters and transcriptomic data from in vivo and in vitro models to show that adult NSCs respond to Wnt/β-catenin signalling. Wnt/β-catenin stimulation instructed neuronal differentiation of NSCs in an active state and promoted the activation or differentiation of quiescent NSCs in a dose-dependent manner. However, we found that deletion of β-catenin in NSCs did not affect their activation or maintenance of their stem cell characteristics. Together, our results indicate that whilst NSCs do respond to Wnt/β-catenin stimulation in a dose-dependent and state-specific manner, Wnt/β-catenin signalling is not cell-autonomously required to maintain NSC homeostasis, which reconciles some of the contradictions in the literature as to the role of Wnt/β-catenin signalling in adult hippocampal NSCs.


Blood ◽  
1990 ◽  
Vol 75 (6) ◽  
pp. 1311-1318 ◽  
Author(s):  
RJ Ford ◽  
A Goodacre ◽  
I Ramirez ◽  
SR Mehta ◽  
F Cabanillas

B-cell non-Hodgkin's lymphomas (NHL-B) have been difficult to establish in long-term cell culture using standard techniques. We report the establishment of five representative cell lines from high grade NHL-B using B-cell growth factor (BCGF). The five NHL-B cell lines display the morphologic, immunophenotypic, genotypic, and biologic characteristics of the lymphoma cells present in the original diagnostic specimen. The cell lines showed at least a sevenfold dose- dependent increase in proliferation in vitro over background in the presence of BCGF. Other putative B-cell growth-stimulating cytokines showed no significant proliferative activity or were inhibitory in some cases. NHL-B cell lines secreted growth factor(s) into culture supernatants that mediated at least a fivefold dose-dependent increase in cell proliferation in autochthonous lymphoma cells and a 10-fold or greater stimulation in growth factor-dependent normal B cell lines in vitro. The cell lines show monoclonal rearrangements of IgH genes and nonrandom chromosomal abnormalities characteristic of NHL-B, while the expression of Epstein-Barr virus associated antigen (EBNA-I) is present in two of the five cell lines. The studies show that lineage-specific growth factors may be used to establish neoplastic B cell lines in vitro, which are important experimental systems for cellular and molecular studies in the NHL-B.


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