scholarly journals Visualizing Drug Efficacy In Vivo

2005 ◽  
Vol 4 (2) ◽  
pp. 153535002005051 ◽  
Author(s):  
Weisheng Zhang ◽  
Min Chen ◽  
David B. West ◽  
Anthony F. Purchio
Keyword(s):  
Enzyme Activity ◽  
Drug Metabolism ◽  
Drug Effects ◽  
Study Drug ◽  
Drug Efficacy ◽  
Biochemical Assays ◽  
Metabolism Enzymes ◽  
First Time ◽  
Cytochrome P 450

Many enzymes are therapeutic targets for drug discovery, whereas other enzymes are important for understanding drug metabolism and pharmacokinetics during compound testing in animals. Testing of drug efficacy and metabolism in an animal model requires the measurement of disease endpoints as well as assays of enzyme activity in specific tissues at selected time points during treatment. This requires the removal of tissue and biochemical assays. Techniques to noninvasively assess drug effects on enzyme activity using imaging technology would facilitate understanding of drug efficacy, pharmacokinetics, and drug metabolism. Using a commercially available cytochrome P−450 3A substrate whose oxidized product is a luciferase substrate, we show for the first time that cytochrome P−450 enzyme activity can be measured in vivo in real time by bioluminescent imaging. This imaging approach could be applicable to study drug effects on therapeutic target enzymes, as well as drug metabolism enzymes.

scholarly journals Circulating Markers Reflect Both Anti- and Pro-Atherogenic Drug Effects in ApoE-Deficient Mice

2008 ◽  
Vol 3 ◽  
pp. BMI.S632 ◽  
Author(s):  
Birong Liao ◽  
Eileen McCall ◽  
Karen Cox ◽  
Chung-Wein Lee ◽  
Shuguang Huang ◽  
...  
Keyword(s):  
Whole Blood ◽  
Plasma Cholesterol ◽  
Drug Effects ◽  
Drug Efficacy ◽  
Vascular Wall ◽  
Atherosclerotic Plaques ◽  
Protein Markers ◽  
Novel Approach ◽  
Coa Reductase

Background Current drug therapy of atherosclerosis is focused on treatment of major risk factors, e.g. hypercholesterolemia while in the future direct disease modification might provide additional benefits. However, development of medicines targeting vascular wall disease is complicated by the lack of reliable biomarkers. In this study, we took a novel approach to identify circulating biomarkers indicative of drug efficacy by reducing the complexity of the in vivo system to the level where neither disease progression nor drug treatment was associated with the changes in plasma cholesterol. Results ApoE-/- mice were treated with an ACE inhibitor ramipril and HMG-CoA reductase inhibitor simvastatin. Ramipril significantly reduced the size of atherosclerotic plaques in brachiocephalic arteries, however simvastatin paradoxically stimulated atherogenesis. Both effects occurred without changes in plasma cholesterol. Blood and vascular samples were obtained from the same animals. In the whole blood RNA samples, expression of MMP9, CD14 and IL-1RN reflected pro-and anti-atherogenic drug effects. In the plasma, several proteins, e.g. IL-1β, IL-18 and MMP9 followed similar trends while protein readout was less sensitive than RNA analysis. Conclusion In this study, we have identified inflammation-related whole blood RNA and plasma protein markers reflecting anti-atherogenic effects of ramipril and pro-atherogenic effects of simwastatin in a mouse model of atherosclerosis. This opens an opportunity for early, non-invasive detection of direct drug effects on atherosclerotic plaques in complex in vivo systems.

scholarly journals Cardioluminescence in transgenic zebrafish embryos: a calcium imaging tool to study drug effects and pathological modeling

2021 ◽  
Author(s):  
Manuel Vicente ◽  
Jussep Salgado-Almario ◽  
Michelle M. Collins ◽  
Antonio Martinez-Sielva ◽  
Masafumi Minoshima ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Light Output ◽  
Drug Effects ◽  
Study Drug ◽  
Transgenic Zebrafish ◽  
Zebrafish Embryos ◽  
Cardiovascular Research ◽  
Imaging Tool ◽  
Adrenergic Blocker

The zebrafish embryo has emerged as an excellent model in cardiovascular research. The existing techniques to monitor Ca2+ in the heart based on fluorescent Ca2+ biosensors are limited due to phototoxicity and photobleaching. To overcome these issues, we have used bioluminescence. We generated a transgenic line expressing GFP-Aequorin in the heart, Tg(cmlc2:GA), and optimized an in vivo aequorin reconstitution protocol to improve the luminescence capacity. This allowed imaging Ca2+ in long duration recordings in embryos of 3 to 5 days post-fertilization. The analogs diacetyl h-coelenterazine and f-coelenterazine enhanced the light output and signal-to-noise ratio from the embryos. With this cardioluminescence model, we monitored the time-averaged Ca2+ levels and beat-to-beat Ca2+ oscillations. Changes in Ca2+ levels were observed by incubation with BayK8644, an L-type Ca2+ channel agonist, the channel blocker nifedipine, and β-adrenergic blocker propranolol. Treatment of zebrafish embryos with terfenadine for 24 hours has been proposed as a model of heart failure. Tg(cmlc2:GA) embryos treated with terfenadine showed a 2:1 atrioventricular block and a decrease in the ventricular Ca2+ levels.

scholarly journals Precocious development of glucuronidating and hydroxylating enzymes in chick embryos treated with pituitary grafts

1975 ◽  
Vol 152 (2) ◽  
pp. 325-331 ◽  
Author(s):  
Graham J. Wishart ◽  
Geoffrey J. Dutton
Keyword(s):  
Chorioallantoic Membrane ◽  
Pars Distalis ◽  
Liver And Kidney ◽  
Embryo Liver ◽  
First Time ◽  
Cytochrome P 450 ◽  
Isolated Liver ◽  
Precocious Development ◽  
Nadph Cytochrome C Reductase

1. Initiation of precocious development of UDP-glucuronyltransferase by an endogenous factor is reported for the first time. 2. This development occurs in chick embryo liver and kidney after grafting of the cephalic lobe of chicken pars-distalis pituitary tissue on to the chorioallantoic membrane, and in liver results in a rise in the enzyme activity from virtually zero to ‘adult’ values. Aniline hydroxylase also precociously develops in the liver of grafted embryos, its activity rising from one-third to the full adult value. Specific activities of glucose 6-phosphatase, cytochrome P-450 and NADPH–cytochrome c reductase did not significantly change. 3. The response of the transferase does not require the presence of host pituitary gland nor, apart from 1 day's necessary initiation, the presence of the graft itself. 4. The host becomes competent to respond on the 14th day of incubation; response continues for at least 3 days after removal of the graft, and for 2 days in the isolated liver. Grafting of embryonic pars distalis younger than 17 days does not evoke a response in the host liver. 5. Secretion of the pituitary factor increases suddenly some 24–48h before the naturally developing surge in liver UDP-glucuronyltransferase activity and may be responsible for initiating this rise in vivo. 6. The factor is probably not a growth or luteinizing hormone; its nature and the likelihood of a secondary hormone acting directly on the liver are discussed.

scholarly journals Molecular Networking for Drug Toxicities Studies: The Case of Hydroxychloroquine in COVID-19 Patients

2021 ◽  
Vol 23 (1) ◽  
pp. 82
Author(s):  
Pierre-Jean Ferron ◽  
Brendan Le Daré ◽  
Julie Bronsard ◽  
Clara Steichen ◽  
Elodie Babina ◽  
...  
Keyword(s):  
Drug Metabolism ◽  
High Resolution Mass Spectrometry ◽  
Study Drug ◽  
University Hospital ◽  
Obese Patients ◽  
Molecular Networking ◽  
Heparg Cells ◽  
In Vitro Data

Using drugs to treat COVID-19 symptoms may induce adverse effects and modify patient outcomes. These adverse events may be further aggravated in obese patients, who often present different illnesses such as metabolic-associated fatty liver disease. In Rennes University Hospital, several drug such as hydroxychloroquine (HCQ) have been used in the clinical trial HARMONICOV to treat COVID-19 patients, including obese patients. The aim of this study is to determine whether HCQ metabolism and hepatotoxicity are worsened in obese patients using an in vivo/in vitro approach. Liquid chromatography high resolution mass spectrometry in combination with untargeted screening and molecular networking were employed to study drug metabolism in vivo (patient’s plasma) and in vitro (HepaRG cells and RPTEC cells). In addition, HepaRG cells model were used to reproduce pathophysiological features of obese patient metabolism, i.e., in the condition of hepatic steatosis. The metabolic signature of HCQ was modified in HepaRG cells cultured under a steatosis condition and a new metabolite was detected (carboxychloroquine). The RPTEC model was found to produce only one metabolite. A higher cytotoxicity of HCQ was observed in HepaRG cells exposed to exogenous fatty acids, while neutral lipid accumulation (steatosis) was further enhanced in these cells. These in vitro data were compared with the biological parameters of 17 COVID-19 patients treated with HCQ included in the HARMONICOV cohort. Overall, our data suggest that steatosis may be a risk factor for altered drug metabolism and possibly toxicity of HCQ.

scholarly journals In VitroAntifungal Susceptibility of Candida glabrata to Caspofungin and the Presence ofFKSMutations Correlate with Treatment Response in an Immunocompromised Murine Model of Invasive Infection

2014 ◽  
Vol 58 (7) ◽  
pp. 3646-3649 ◽  
Author(s):  
Fabiola Fernández-Silva ◽  
Michaela Lackner ◽  
Javier Capilla ◽  
Emilio Mayayo ◽  
Deanna Sutton ◽  
...  
Keyword(s):  
Murine Model ◽  
Hot Spot ◽  
Drug Efficacy ◽  
Invasive Infection ◽  
Content Type ◽  
Wide Range ◽  
Systemic Infections ◽  
First Time

ABSTRACTIt has been argued that thein vitroactivity of caspofungin (CSP) is not a good predictor of the outcome of echinocandin treatmentin vivo. We evaluated thein vitroactivity of CSP and the presence ofFKSmutations in the hot spot 1 (HS1) region of theFKS1andFKS2genes in 17 Candida glabratastrains with a wide range of MICs. The efficacy of CSP against systemic infections from each of the 17 strains was evaluated in a murine model. No HS1 mutations were found in the eight strains showing MICs for CSP of ≤0.5 μg/ml, but they were present in eight of the nine strains with MICs of ≥1 μg/ml, i.e., three in theFKS1gene and five in theFKS2gene. CSP was effective for treating mice infected with strains with MICs of ≤0.5 μg/ml, showed variable efficacy in animals challenged with strains with MICs of 1 μg/ml, and did not work in those with strains with MICs of >1 μg/ml. In addition, mutations, including one reported for the first time, were found outside the HS1 region in theFKS2gene of six strains with different MICs, but their presence did not influence drug efficacy. Thein vitroactivity of CSP was compared with that of another echinocandin, anidulafungin, suggesting that the MICs of both drugs, as well as mutations in the HS1 regions of theFKS1andFKS2genes, are predictive of outcome.

Sign in / Sign up

Export Citation Format

Share Document