Opiate-induced Analgesia Is Increased and Prolonged in Mice Lacking P-glycoprotein

Background P-glycoprotein is a transmembrane protein expressed by multiple mammalian cell types, including the endothelial cells that comprise the blood-brain-barrier. P-glycoprotein functions to actively pump a diverse array of xenobiotics out of the cells in which it is expressed. The purpose of this study was to determine if P-glycoprotein alters the analgesic efficacy of clinically useful opioids. Methods Using a standard hot-plate method, the magnitude and duration of analgesia from morphine, morphine-6-glucuronide, methadone, meperidine, and fentanyl were assessed in wild-type Friends virus B (FVB) mice and in FVB mice lacking P-glycoprotein [mdr1a/b(-/-)]. Analgesia was expressed as the percent maximal possible effect (%MPE) over time, and these data were used to calculate the area under the analgesia versus time curves (AUC) for all opioids studied. In addition, the effect of a P-glycoprotein inhibitor (cyclosporine, 100 mg/kg) on morphine analgesia in both wild-type and mdr knockout mice was also determined. Results Morphine induced greater analgesia in knockout mice compared with wild-type mice (AUC 6,450 %MPE min vs. 1,610 %MPE min at 3 mg/kg), and morphine brain concentrations were greater in knockout mice. Analgesia was also greater in knockout mice treated with methadone and fentanyl but not meperidine or morphine-6-glucuronide. Cyclosporine pretreatment markedly increased morphine analgesia in wild-type mice but had no effect in knockout mice. Conclusions These results suggest that P-glycoprotein acts to limit the entry of some opiates into the brain and that acute administration of P-glycoprotein inhibitors can increase the sensitivity to these opiates.

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A Revised Role for P-Glycoprotein in the Brain Distribution of Dexamethasone, Cortisol, and Corticosterone in Wild-Type and ABCB1A/B-Deficient Mice

Endocrinology ◽

10.1210/en.2008-0041 ◽

2008 ◽

Vol 149 (10) ◽

pp. 5244-5253 ◽

Cited By ~ 40

Author(s):

Brittany L. Mason ◽

Carmine M. Pariante ◽

Sarah A. Thomas

Keyword(s):

Brain Distribution ◽

Wild Type ◽

P Glycoprotein ◽

The Brain ◽

Deficient Mice

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Interaction of Morphine, Fentanyl, Sufentanil, Alfentanil, and Loperamide with the Efflux Drug Transporter P-glycoprotein

Anesthesiology ◽

10.1097/00000542-200204000-00019 ◽

2002 ◽

Vol 96 (4) ◽

pp. 913-920 ◽

Cited By ~ 156

Author(s):

Christoph Wandel ◽

Richard Kim ◽

Margaret Wood ◽

Alastair Wood

Keyword(s):

Animal Studies ◽

Wide Spectrum ◽

Cell Monolayer ◽

Cell Monolayers ◽

P Glycoprotein ◽

Ic50 Values ◽

The Hill ◽

Glycoprotein Inhibitors ◽

Directional Transport ◽

The Brain

Background The efflux transporter P-glycoprotein, a member of the adenosine triphosphate-binding cassette superfamily, is a major determinant of the pharmacokinetics and pharmacodynamics of the opioid loperamide, a well-recognized antidiarrheal agent. Animal studies indicate that P-glycoprotein limits morphine entry into the brain. In this study, the authors examined whether other opioids of importance to anesthesiologists such as fentanyl, sufentanil, and alfentanil, and also morphine-6-glucuronide and morphine-3-glucuronide, are P-glycoprotein substrates and whether, in turn, these opioids act also as P-glycoprotein inhibitors. Methods The transcellular movement of the various opioids, including loperamide and morphine, was assessed in L-MDR1 (expressing P-glycoprotein) and LLC-PK1 cell monolayers (P-glycoprotein expression absent). A preferential basal-to-apical versus apical-to-basal transport in the L-MDR cells but not the LLC-PK1 cells is seen for P-glycoprotein substrates. In addition, the effect of the various opioids on the transcellular movement of the prototypical P-glycoprotein substrate digoxin was examined in Caco-2 cell monolayers. IC50 values were calculated according to the Hill equation. Results Loperamide was a substrate showing high dependence on P-glycoprotein in that basal-apical transport was nearly 10-fold greater than in the apical-basal direction in L-MDRI cells. Morphine also showed a basal-to-apical gradient in the L-MDR1 cell monolayer, indicating that it too is a P-glycoprotein substrate, but with less dependence than loperamide in that only 1.5-fold greater basal-apical directional transport was observed. Fentanyl, sufentanil, and alfentanil did not behave as P-glycoprotein substrates, whereas the morphine glucuronides did not cross the cell monolayers at all, whether P-glycoprotein was present or not. Loperamide, sufentanil, fentanyl, and alfentanil inhibited P-glycoprotein-mediated digoxin transport in Caco-2 cells with IC50 values of 2.5, 4.5, 6.5, and 112 microm, respectively. Morphine and its glucuronides (20 microm) did not inhibit digoxin (5 microm) transport in Caco-2 cells, and therefore IC50 values were not determined. Conclusions Opioids have a wide spectrum of P-glycoprotein activity, acting as both substrates and inhibitors, which might contribute to their varying central nervous system-related effects.

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Presence of a D2 receptor truncated protein in the brain of the D2 receptor functional knockout mouse, revisiting its molecular and neurochemical features

10.1101/757609 ◽

2019 ◽

Author(s):

Natalia Sánchez ◽

Montserrat Olivares-Costa ◽

Marcela P González ◽

Angélica P Escobar ◽

Rodrigo Meza ◽

...

Keyword(s):

Knockout Mice ◽

Knockout Mouse ◽

Transmembrane Domain ◽

Dopamine D2 Receptor ◽

D2 Receptor ◽

Wild Type ◽

Intracellular Loop ◽

Protein Protein Interaction ◽

Acute Injection ◽

The Brain

AbstractNull mice for the dopamine D2 receptor (D2R) have been instrumental in understanding the function of this protein in the central nervous system. Several lines of D2R knockout mice have been generated, which share some characteristics but differ in others. The D2R functional knockout mouse, first described in 1997, is functionally null for D2R-mediated signaling but the Drd2 gene was interrupted at the most extreme distal end leaving open the question about whether transcript and protein are produced. We decided to determine if there are D2R transcripts, the characteristics of these transcripts and whether they are translated in the brain of D2R functional knockout mice. Sequence analysis of 3’ Rapid Amplification of cDNA Ends showed that D2R functional knockout mice express transcripts that lack only the exon eight. Immunofluorescence showed D2R-like protein in the brain of the knockout mice. As previously reported, D2R functional knockout mice are hypoactive and insensitive to the D2R agonist quinpirole (QNP). However, the heterozygous showed locomotor activity and response to QNP similar to the wild-type mice. Intriguingly, microdialysis experiments showed that heterozygous mice, such as knockouts, have half the normal levels of synaptic dopamine in the striatum. However, heterozygous mice responded similarly to wild-type mice to an acute injection of QNP, showing a 50% decrease in synaptic dopamine. In conclusion, D2R functional knockout mice express transcripts that lead to a truncated D2R protein that lacks from the sixth transmembrane domain to the C-terminal end but retains the third intracellular loop. We discuss the implications of this truncated D2R coexisting with the native D2R that may explain the unexpected outcomes observed in the heterozygous. Finally, we suggest that the D2R functional knockout mouse can be a useful model for studying protein-protein interaction and trafficking of D2R.

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MRI of Capn15 knockout mice and analysis of Capn15 distribution reveal possible roles in brain development and plasticity

10.1101/763888 ◽

2019 ◽

Cited By ~ 1

Author(s):

Congyao Zha ◽

Carole A Farah ◽

Vladimir Fonov ◽

David A. Rudko ◽

Wayne S Sossin

Keyword(s):

Brain Development ◽

Knockout Mice ◽

Brain Plasticity ◽

Small Animal ◽

Cell Types ◽

Cysteine Proteases ◽

Brain Regions ◽

Conditional Knockout ◽

Specific Cell ◽

The Brain

AbstractPurposeThe non-classical Small Optic Lobe (SOL) family of calpains are intracellular cysteine proteases that are expressed in the nervous system and appear to play an important role in neuronal development in both Drosophila, where loss of this calpain leads to the eponymous small optic lobes, and in mouse and human, where loss of this calpain (Capn15) leads to eye anomalies. However, the brain regions where this calpain is expressed and the areas most affected by the loss of this calpain have not been carefully examined.ProceduresWe utilize an insert strain where lacZ is expressed under the control of the Capn15 promoter, together with immunocytochemistry with markers of specific cell types to address where Capn 15 is expressed in the brain. We use small animal MRI comparing WT, Capn15 knockout and Capn15 conditional knockout mice to address the brain regions that are affected when Capn 15 is not present, either in early development of the adult.ResultsCapn15 is expressed in diverse brain regions, many of them involved in plasticity such as the hippocampus, lateral amygdala and Purkinje neurons. Capn15 knockout mice have smaller brains, and present specific deficits in the thalamus and hippocampal regions. There are no deficits revealed by MRI in brain regions when Capn15 is knocked out after development.ConclusionsAreas where Capn15 is expressed in the adult are not good markers for the specific regions where the loss of Capn15 specifically affects brain development. Thus, it is likely that this calpain plays distinct roles in brain development and brain plasticity.

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Distribution of Suramin, an Antitrypanosomal Drug, across the Blood-Brain and Blood-Cerebrospinal Fluid Interfaces in Wild-Type and P-Glycoprotein Transporter-Deficient Mice

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00372-07 ◽

2007 ◽

Vol 51 (9) ◽

pp. 3136-3146 ◽

Cited By ~ 25

Author(s):

Lisa Sanderson ◽

Adil Khan ◽

Sarah Thomas

Keyword(s):

Choroid Plexus ◽

Brain Perfusion ◽

Brain Parenchyma ◽

Sleeping Sickness ◽

New Drugs ◽

Wild Type ◽

P Glycoprotein ◽

Blood Brain ◽

Targeted Mutation ◽

The Brain

ABSTRACT Although 60 million people are exposed to human African trypanosomiasis, drug companies have not been interested in developing new drugs due to the lack of financial reward. No new drugs will be available for several years. A clearer understanding of the distribution of existing drugs into the brains of sleeping sickness patients is needed if we are to use the treatments that are available more safely and effectively. This proposal addresses this issue by using established animal models. Using in situ brain perfusion and isolated incubated choroid plexus techniques, we investigated the distribution of [3H]suramin into the central nervous systems (CNSs) of male BALB/c, FVB (wild-type), and P-glycoprotein-deficient (Mdr1a/Mdr1b-targeted mutation) mice. There was no difference in the [3H]suramin distributions between the three strains of mice. [3H]suramin had a distribution similar to that of the vascular marker, [14C]sucrose, into the regions of the brain parenchyma that have a blood-brain barrier. However, the association of [3H]suramin with the circumventricular organ samples, including the choroid plexus, was higher than that of [14C]sucrose. The association of [3H]suramin with the choroid plexus was also sensitive to phenylarsine oxide, an inhibitor of endocytosis. The distribution of [3H]suramin to the brain was not affected by the presence of other antitrypanosomal drugs or the P-glycoprotein efflux transporter. Overall, the results confirm that [3H]suramin would be unlikely to treat the second or CNS stage of sleeping sickness.

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The Spike Glycoprotein of Murine Coronavirus MHV-JHM Mediates Receptor-Independent Infection and Spread in the Central Nervous Systems of Ceacam1a−/− Mice

Journal of Virology ◽

10.1128/jvi.01851-07 ◽

2007 ◽

Vol 82 (2) ◽

pp. 755-763 ◽

Cited By ~ 39

Author(s):

Tanya A. Miura ◽

Emily A. Travanty ◽

Lauren Oko ◽

Helle Bielefeldt-Ohmann ◽

Susan R. Weiss ◽

...

Keyword(s):

Hepatitis Virus ◽

Lethal Dose ◽

Cell Types ◽

Wild Type ◽

Spike Glycoprotein ◽

Susceptibility To Infection ◽

Spread Of Infection ◽

The Brain ◽

Murine Coronavirus

ABSTRACT The MHV-JHM strain of the murine coronavirus mouse hepatitis virus is much more neurovirulent than the MHV-A59 strain, although both strains use murine CEACAM1a (mCEACAM1a) as the receptor to infect murine cells. We previously showed that Ceacam1a −/− mice are completely resistant to MHV-A59 infection (E. Hemmila et al., J. Virol. 78:10156-10165, 2004). In vitro, MHV-JHM, but not MHV-A59, can spread from infected murine cells to cells that lack mCEACAM1a, a phenomenon called receptor-independent spread. To determine whether MHV-JHM could infect and spread in the brain independent of mCEACAM1a, we inoculated Ceacam1a −/− mice. Although Ceacam1a −/− mice were completely resistant to i.c. inoculation with 106 PFU of recombinant wild-type MHV-A59 (RA59) virus, these mice were killed by recombinant MHV-JHM (RJHM) and a chimeric virus containing the spike of MHV-JHM in the MHV-A59 genome (SJHM/RA59). Immunohistochemistry showed that RJHM and SJHM/RA59 infected all neural cell types and induced severe microgliosis in both Ceacam1a −/− and wild-type mice. For RJHM, the 50% lethal dose (LD50) is <101.3 in wild-type mice and 103.1 in Ceacam1a −/− mice. For SJHM/RA59, the LD50 is <101.3 in wild-type mice and 103.6 in Ceacam1a −/− mice. This study shows that infection and spread of MHV-JHM in the brain are dependent upon the viral spike glycoprotein. RJHM can initiate infection in the brains of Ceacam1a −/− mice, but expression of mCEACAM1a increases susceptibility to infection. The spread of infection in the brain is mCEACAM1a independent. Thus, the ability of the MHV-JHM spike to mediate mCEACAM1a-independent spread in the brain is likely an important factor in the severe neurovirulence of MHV-JHM in wild-type mice.

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α-1-Adrenergic Receptor Agonist Activity of Clinical α-Adrenergic Receptor Agonists Interferes with α-2-Mediated Analgesia

Anesthesiology ◽

10.1097/aln.0b013e3181943226 ◽

2009 ◽

Vol 110 (2) ◽

pp. 401-407 ◽

Cited By ~ 6

Author(s):

Daniel W. Gil ◽

Cynthia V. Cheevers ◽

Karen M. Kedzie ◽

Cynthia A. Manlapaz ◽

Sandhya Rao ◽

...

Keyword(s):

Knockout Mice ◽

Adrenergic Receptor ◽

Receptor Agonist ◽

Intraperitoneal Administration ◽

Analgesic Efficacy ◽

Therapeutic Window ◽

Receptor Subtypes ◽

Agonist Activity ◽

Wild Type

Background The use of alpha-2 adrenergic agonists for analgesia is limited due to a narrow therapeutic window. Definition of the role of alpha receptor subtypes in alpha agonist mediated analgesia may identify strategies to separate the analgesic from sedative and cardiovascular effects. Methods Analgesic activity of brimonidine, clonidine, and tizanidine was investigated in wild-type C57B/6, alpha-2A, and alpha-2C knockout mice with allodynia induced by N-methyl-D-aspartate or sulprostone. The alpha receptor selectivity of the alpha agonists was assessed using functional in vitro recombinant assays. Results Brimonidine, clonidine, and tizanidine reduced N-methyl-D-aspartate- and sulprostone-induced allodynia in wild-type mice, but not alpha-2A knockout mice. In alpha-2C knockout mice, brimonidine and tizanidine reduced allodynia in both models, whereas clonidine only reduced N-methyl-D-aspartate-induced allodynia. In vitro, clonidine and tizanidine activated alpha-1 and alpha-2 receptors with similar potencies, whereas brimonidine was selective for alpha-2 receptors. In alpha-2C knockout mice with sulprostone-induced allodynia, blockade of clonidine's alpha-1 receptor agonist activity restored clonidine's analgesic efficacy. In wild-type mice, the analgesic potency of intrathecal clonidine and tizanidine was increased 3- to 10-fold by coadministration with the alpha-1A-selective antagonist 5-methylurapidil without affecting sedation. Following intraperitoneal administration, the therapeutic window was negligible for clonidine and tizanidine, but greater for brimonidine. 5-Methylurapidil enhanced the therapeutic window of intraperitoneal clonidine and tizanidine approximately 10-fold. Conclusions Alpha-1A receptor agonist activity can counterbalance alpha-2 receptor agonist-induced analgesia. Greater alpha-2 selectivity may enhance the therapeutic window of alpha-2 agonists in the treatment of pain.

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Salivary Aβ Secretion and Altered Oral Microbiome in Mouse Models of AD

Current Alzheimer Research ◽

10.2174/1567205018666210119151952 ◽

2021 ◽

Vol 17 (12) ◽

pp. 1133-1144

Author(s):

Angela M. Floden ◽

Mona Sohrabi ◽

Suba Nookala ◽

Jay J. Cao ◽

Colin K. Combs

Keyword(s):

Matched Control ◽

Amyloid Β ◽

Cell Types ◽

Oral Microbiome ◽

Aβ Peptide ◽

Prior Work ◽

Wild Type ◽

Male And Female ◽

Amyloid Aβ ◽

The Brain

Background: Beta amyloid (Aβ) peptide containing plaque aggregations in the brain are a hallmark of Alzheimer’s Disease (AD). However, Aβ is produced by cell types outside of the brain suggesting that the peptide may serve a broad physiologic purpose. Objective: Based upon our prior work documenting expression of amyloid β precursor protein (APP) in intestinal epithelium we hypothesized that salivary epithelium might also express APP and be a source of Aβ. Methods: To begin testing this idea, we compared human age-matched control and AD salivary glands to C57BL/6 wild type, AppNL-G-F , and APP/PS1 mice. Results: Both male and female AD, AppNL-G-F , and APP/PS1 glands demonstrated robust APP and Aβ immunoreactivity. Female AppNL-G-F mice had significantly higher levels of pilocarpine stimulated Aβ 1-42 compared to both wild type and APP/PS1 mice. No differences in male salivary Aβ levels were detected. No significant differences in total pilocarpine stimulated saliva volumes were observed in any group. Both male and female AppNL-G-F but not APP/PS1 mice demonstrated significant differences in oral microbiome phylum and genus abundance compared to wild type mice. Male, but not female, APP/PS1 and AppNL-G-F mice had significantly thinner molar enamel compared to their wild type counterparts. Conclusion: These data support the idea that oral microbiome changes exist during AD in addition to changes in salivary Aβ and oral health.

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