Correction to “In Vivo-to-in Vitro Extrapolation of Transporter-Mediated Renal Clearance: Relative Expression Factor Versus Relative Activity Factor Approach”

Abstract Objectives Isobavachin is a phenolic with anti-osteoporosis activity. This study aimed to explore its metabolic fates in vivo and in vitro, and to investigate the potential drug–drug interactions involving CYPs and UGTs. Methods Metabolites of isobavachin in mice were first identified and characterized. Oxidation and glucuronidation study were performed using liver and intestine microsomes. Reaction phenotyping, activity correlation analysis and relative activity factor approaches were employed to identify the main CYPs and UGTs involved in isobavachin metabolism. Through kinetic modelling, inhibition mechanisms towards CYPs and UGTs were also explored. Key findings Two glucuronides (G1 - G2) and three oxidated metabolites (M1 - M3) were identified in mice. Additionally, isobavachin underwent efficient oxidation and glucuronidation by human liver microsomes and HIM with CLint values from 5.53 to 148.79 μl/min per mg. CYP1A2, 2C19 contributed 11.3% and 17.1% to hepatic metabolism of isobavachin, respectively, with CLint values from 8.75 to 77.33 μl/min per mg. UGT1As displayed CLint values from 10.73 to 202.62 μl/min per mg for glucuronidation. Besides, significant correlation analysis also proved that CYP1A2, 2C19 and UGT1A1, 1A9 were main contributors for the metabolism of isobavachin. Furthermore, mice may be the appropriate animal model for predicting its metabolism in human. Moreover, isobavachin exhibited broad inhibition against CYP2B6, 2C9, 2C19, UGT1A1, 1A9, 2B7 with Ki values from 0.05 to 3.05 μm. Conclusions CYP1A2, 2C19 and UGT1As play an important role in isobavachin metabolism. Isobavachin demonstrated broad-spectrum inhibition of CYPs and UGTs.

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IVIVE of Transporter-Mediated Renal Clearance: Relative Expression Factor (REF) vs Relative Activity Factor (RAF) Approach

Drug Metabolism and Disposition ◽

10.1124/dmd.121.000367 ◽

2021 ◽

pp. DMD-AR-2021-000367

Author(s):

Aditya R. Kumar ◽

Bhagwat Prasad ◽

Deepak Kumar Bhatt ◽

Sumathy Mathialagan ◽

Manthena V. S. Varma ◽

...

Keyword(s):

Renal Clearance ◽

Relative Activity ◽

Relative Expression ◽

Activity Factor

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Quantitative Prediction of Human Renal Clearance and Drug-Drug Interactions of Organic Anion Transporter Substrates Using In Vitro Transport Data: A Relative Activity Factor Approach

Drug Metabolism and Disposition ◽

10.1124/dmd.116.074294 ◽

2017 ◽

Vol 45 (4) ◽

pp. 409-417 ◽

Cited By ~ 35

Author(s):

Sumathy Mathialagan ◽

Mary A. Piotrowski ◽

David A. Tess ◽

Bo Feng ◽

John Litchfield ◽

...

Keyword(s):

Drug Interactions ◽

Renal Clearance ◽

Organic Anion ◽

Relative Activity ◽

Organic Anion Transporter ◽

Quantitative Prediction ◽

Anion Transporter ◽

Activity Factor

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Comparison of the Anticoagulant and Antithrombotic Effects of Synthetic Thrombin and Factor Xa Inhibitors

Thrombosis and Haemostasis ◽

10.1055/s-0038-1645198 ◽

1990 ◽

Vol 63 (02) ◽

pp. 220-223 ◽

Cited By ~ 19

Author(s):

J Hauptmann ◽

B Kaiser ◽

G Nowak ◽

J Stürzebecher ◽

F Markwardt

Keyword(s):

Factor Xa ◽

Thrombin Inhibitors ◽

Factor Xa Inhibitors ◽

Venous Stasis ◽

Clotting Time ◽

Thrombosis Model ◽

Activity Factor ◽

Antithrombotic Effects

SummaryThe anticoagulant effect of selected synthetic inhibitors of thrombin and factor Xa was studied in vitro in commonly used clotting assays. The concentrations of the compounds doubling the clotting time in the various assays were mainly dependent on their thrombin inhibitory activity. Factor Xa inhibitors were somewhat more effective in prolonging the prothrombin time compared to the activated partial thromboplastin time, whereas the opposite was true of thrombin inhibitors.In vivo, in a venous stasis thrombosis model and a thromboplastin-induced microthrombosis model in rats the thrombin inhibitors were effective antithrombotically whereas factor Xa inhibitors of numerically similar IQ value for the respective enzyme were not effective at equimolar dosageThe results are discussed in the light of the different prelequisiles and conditions for inhibition of thrombin and factor Xa in the course of blood clotting.

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Relative expression of mRNAs related to cavitation process in bovine embryos produced in vivo and in vitro

Revista Brasileira de Zootecnia ◽

10.1590/s1516-35982011000100017 ◽

2011 ◽

Vol 40 (1) ◽

pp. 124-128

Author(s):

Sabine Wohlres-Viana ◽

Mariana Cortes Boite ◽

João Henrique Moreira Viana ◽

Marco Antonio Machado ◽

Luiz Sérgio de Almeida Camargo

Keyword(s):

Culture System ◽

Rna Extraction ◽

Endogenous Control ◽

Bovine Embryos ◽

Relative Expression ◽

Gapdh Gene ◽

Expression Of Genes ◽

In Vitro Culture System

The objectives of this work were to identify and to evaluate possible differences on gene expression of aquaporins and Na/K-ATPases transcripts between embryos in vivo and in vitro produced. For each group, 15 blastocysts distributed in three pools were used for RNA extraction followed by amplification and reverse transcription. The resulting cDNAs were submitted to Real-Time PCR, using the GAPDH gene as endogenous control. It was not possible to identify AQP1 transcripts. Relative expression of AQP3 (1.33 ± 0.78) and AQP11 (2.00 ± 1.42) were not different in blastocysts in vitro and in vivo produced. Na/K-ATPase α1 gene (2.25 ± 1.07) was overregulated whereas Na/K-ATPase β2 transcripts 0.40 ± 0.30) did not differ among blastocysts produced in vitro from those produced in vivo. Transcripts for gene AQP1 are not present in bovine blastocysts. In vitro culture system does not alter expression of genes AQP3, AQP11 and Na/K-ATPase β2 genes, however, it affects expression of Na/K-ATPase α1.

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Vascular smooth muscle function of renal glomerular and interlobar arteries predicts renal damage in rats

AJP Renal Physiology ◽

10.1152/ajprenal.00653.2011 ◽

2012 ◽

Vol 303 (8) ◽

pp. F1187-F1195 ◽

Cited By ~ 4

Author(s):

Peter Vavrinec ◽

Robert H. Henning ◽

Maaike Goris ◽

Diana Vavrincova-Yaghi ◽

Hendrik Buikema ◽

...

Keyword(s):

Blood Pressure ◽

Intravital Microscopy ◽

Renal Damage ◽

Renal Arteries ◽

Ang Ii ◽

Vascular Integrity ◽

Relative Expression ◽

Glomerular Arterioles

Previously, it was shown that individuals with good baseline (a priori) endothelial function in isolated (in vitro) renal arteries developed less renal damage after ⅚ nephrectomy (5/6Nx; Gschwend S, Buikema H, Navis G, Henning RH, de Zeeuw D, van Dokkum RP. J Am Soc Nephrol 13: 2909–2915, 2002). In this study, we investigated whether preexisting glomerular vascular integrity predicts subsequent renal damage after 5/6Nx, using in vivo intravital microscopy and in vitro myogenic constriction of small renal arteries. Moreover, we aimed to elucidate the role of renal ANG II type 1 receptor (AT1R) expression in this model. Anesthetized rats underwent intravital microscopy to visualize constriction to ANG II of glomerular afferent and efferent arterioles, with continuous measurement of blood pressure, heart rate, and renal blood flow. Thereafter, 5/6Nx was performed, interlobar arteries were isolated from the extirpated kidney, and myogenic constriction was assessed in a perfused vessel setup. Blood pressure and proteinuria were assessed weekly for 12 wk, and focal glomerulosclerosis (FGS) was determined at the end of study. Relative expression AT1R in the kidney cortex obtained at 5/6Nx was determined by PCR. Infusion of ANG II induced significant constriction of both afferent and efferent glomerular arterioles, which strongly positively correlated with proteinuria and FGS at 12 wk after 5/6Nx. Furthermore, in vitro measured myogenic constriction of small renal arteries negatively correlated with proteinuria 12 wk after 5/6Nx. Moreover, in vivo vascular reactivity negatively correlated with in vitro reactivity. Additionally, relative expression of AT1R positively correlated with responses of glomerular arterioles and with markers of renal damage. Both in vivo afferent and efferent responses to ANG II and in vitro myogenic constriction of small renal arteries in the healthy rat predict the severity of renal damage induced by 5/6Nx. This vascular responsiveness is highly dependent on AT1R expression. Intraorgan vascular integrity may provide a useful tool to guide the prevention and treatment of renal end-organ damage.

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Phosphatidylethanolamine in Liver Mitochondria and Endoplasmic Reticulum; Molecular Species Distribution and Turnover

Canadian Journal of Biochemistry ◽

10.1139/o75-096 ◽

1975 ◽

Vol 53 (6) ◽

pp. 698-705 ◽

Cited By ~ 8

Author(s):

J. G. Parkes ◽

W. Thompson

Keyword(s):

Endoplasmic Reticulum ◽

Fatty Acid ◽

Specific Activity ◽

Liver Mitochondria ◽

Relative Activity ◽

Layer Chromatography ◽

Kinetics Of ◽

Fatty Acid Compositions

Phosphatidylethanolamine from mitochondria and microsomes of guinea pig liver was separated by thin-layer chromatography into eight different classes differing in degree of unsaturation. The fatty acid compositions and molar proportions of each class isolated from microsomes were very similar to the corresponding class in mitochondria. In both organelles about half of the total was dienoic species while tetraenes comprised approximately 20%. Stearic acid was the major saturated fatty acid and in each membrane a greater selectivity for stearate over palmitate was found in each sub-class of phosphatidylethanolamine, when compared with the corresponding class of phosphatidylcholine.Following the intraperitoneal injection of [2-3H]glycerol, the labelling of each molecular class of phosphatidylethanolamine showed very similar progressions in microsomes and mitochondria over a 3 h interval. In both organelles the highest relative specific activity was attained by penta-plus hexaenoic classes, while the large dienoic class had the lowest relative activity, which, however, increased with time. Analysis of the dienoic class of phosphatidylethanolamine from whole liver showed it to be constituted by a rapidly turning over palmitoyl–linoleoyl fraction and a slowly labelled stearoyl–linoleoyl fraction, a pattern also exhibited by dienoic phosphatidylcholines.The similarities in profile of molecular classes of phosphatidylethanolamine and in the kinetics of labelling in vivo point to a close metabolic relation between the lipids of both organelles, suggestive of a transfer of different molecular classes at comparable rates from the endoplasmic reticulum, the site of synthesis, to the mitochondria. This is consistent with numerous other studies in vitro that have demonstrated inter-organelle exchange of lipids.

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Evaluation of Antibiotics Active against Methicillin-Resistant Staphylococcus aureus Based on Activity in an Established Biofilm

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01251-16 ◽

2016 ◽

Vol 60 (10) ◽

pp. 5688-5694 ◽

Cited By ~ 23

Author(s):

Daniel G. Meeker ◽

Karen E. Beenken ◽

Weston B. Mills ◽

Allister J. Loughran ◽

Horace J. Spencer ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Biofilm Formation ◽

Limit Of Detection ◽

Relative Activity ◽

Methicillin Resistant ◽

Content Type ◽

Comparable Activity ◽

Antibiotic Delivery

ABSTRACTWe usedin vitroandin vivomodels of catheter-associated biofilm formation to compare the relative activity of antibiotics effective against methicillin-resistantStaphylococcus aureus(MRSA) in the specific context of an established biofilm. The results demonstrated that, underin vitroconditions, daptomycin and ceftaroline exhibited comparable activity relative to each other and greater activity than vancomycin, telavancin, oritavancin, dalbavancin, or tigecycline. This was true when assessed using established biofilms formed by the USA300 methicillin-resistant strain LAC and the USA200 methicillin-sensitive strain UAMS-1. Oxacillin exhibited greater activity against UAMS-1 than LAC, as would be expected, since LAC is an MRSA strain. However, the activity of oxacillin was less than that of daptomycin and ceftaroline even against UAMS-1. Among the lipoglycopeptides, telavancin exhibited the greatest overall activity. Specifically, telavancin exhibited greater activity than oritavancin or dalbavancin when tested against biofilms formed by LAC and was the only lipoglycopeptide capable of reducing the number of viable bacteria below the limit of detection. With biofilms formed by UAMS-1, telavancin and dalbavancin exhibited comparable activity relative to each other and greater activity than oritavancin. Importantly, ceftaroline was the only antibiotic that exhibited greater activity than vancomycin when testedin vivoin a murine model of catheter-associated biofilm formation. These results emphasize the need to consider antibiotics other than vancomycin, most notably, ceftaroline, for the treatment of biofilm-associatedS. aureusinfections, including by the matrix-based antibiotic delivery methods often employed for local antibiotic delivery in the treatment of these infections.

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