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1.
Sci Rep ; 12(1): 484, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013352

RESUMO

Treatment with a nicotinamide N-methyltransferase inhibitor (NNMTi; 5-amino-1-methylquinolinium) combined with low-fat diet (LD) promoted dramatic whole-body adiposity and weight loss in diet-induced obese (DIO) mice, rapidly normalizing these measures to age-matched lean animals, while LD switch alone was unable to restore these measures to age-matched controls in the same time frame. Since mouse microbiome profiles often highly correlate with body weight and fat composition, this study was designed to test whether the cecal microbiomes of DIO mice treated with NNMTi and LD were comparable to the microbiomes of age-matched lean counterparts and distinct from microbiomes of DIO mice maintained on a high-fat Western diet (WD) or subjected to LD switch alone. There were minimal microbiome differences between lean and obese controls, suggesting that diet composition and adiposity had limited effects. However, DIO mice switched from an obesity-promoting WD to an LD (regardless of treatment status) displayed several genera and phyla differences compared to obese and lean controls. While alpha diversity measures did not significantly differ between groups, beta diversity principal coordinates analyses suggested that mice from the same treatment group were the most similar. K-means clustering analysis of amplicon sequence variants by animal demonstrated that NNMTi-treated DIO mice switched to LD had a distinct microbiome pattern that was highlighted by decreased Erysipelatoclostridium and increased Lactobacillus relative abundances compared to vehicle counterparts; these genera are tied to body weight and metabolic regulation. Additionally, Parasutterella relative abundance, which was increased in both the vehicle- and NNMTi-treated LD-switched groups relative to the controls, significantly correlated with several adipose tissue metabolites' abundances. Collectively, these results provide a novel foundation for future investigations.


Assuntos
Inibidores Enzimáticos/administração & dosagem , Microbioma Gastrointestinal/efeitos dos fármacos , Nicotinamida N-Metiltransferase/antagonistas & inibidores , Nicotinamida N-Metiltransferase/metabolismo , Obesidade/dietoterapia , Obesidade/tratamento farmacológico , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Adiposidade/efeitos dos fármacos , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Peso Corporal/efeitos dos fármacos , Terapia Combinada , Dieta com Restrição de Gorduras , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Nicotinamida N-Metiltransferase/genética , Obesidade/metabolismo , Obesidade/microbiologia , Compostos de Quinolínio/administração & dosagem
2.
Anat Rec (Hoboken) ; 302(11): 1950-1957, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31177611

RESUMO

Glioblastoma multiforme (GBM) is the most common type of malignant glioma. Bufothionine is one of the major active ingredients of Cinobufacini. Although the antitumor activities of bufothionine have been reported, the underlying mechanism remains unclear. The present study showed that bufothionine exhibited antigrowth activities in GBM cell lines U87 and U373. Further investigation showed that bufothionine triggered endoplasmic reticulum (ER) stress to promote apoptosis in U87 and U373 cells. Moreover, our results showed that bufothionine exhibited synergistic activities with Temozolomide (TMZ) to suppress the growth of U87 and U373 cells. The findings in the present study provide basis for further investigation of the therapeutic potential of bufothionine in GBM. Anat Rec, 302:1950-1957, 2019. © 2019 American Association for Anatomy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose , Neoplasias Encefálicas/patologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Glioblastoma/patologia , Neoplasias Encefálicas/tratamento farmacológico , Proliferação de Células , Sinergismo Farmacológico , Glioblastoma/tratamento farmacológico , Humanos , Alcaloides Indólicos/administração & dosagem , Compostos de Quinolínio/administração & dosagem , Temozolomida/administração & dosagem , Células Tumorais Cultivadas
3.
Bioelectrochemistry ; 126: 29-37, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30472569

RESUMO

We performed the transformation of a wild type Chlamydomonas reinhardtii by optimizing previously developed droplet EP method. For more effective and faster optimization, we used DNA dying fluorescent molecule (Yo-Pro-1) for finding optimal EP conditions instead of using protein expression based evaluation method. By examining wider range of electrical parameter space together with the analysis of total current flow of EP process, we found optimal EP conditions. The obtained optimal EP conditions were verified by CFP transgene expression experiments. By applying the optimal EP conditions to the transformation of C. reinhardtii, we obtained transformants and analyzed them using PCR. Finally, implications and future work are discussed.


Assuntos
Chlamydomonas reinhardtii/genética , Eletroporação/métodos , Transformação Genética , Benzoxazóis/administração & dosagem , Benzoxazóis/análise , DNA/administração & dosagem , DNA/genética , Eletroporação/instrumentação , Desenho de Equipamento , Corantes Fluorescentes/administração & dosagem , Corantes Fluorescentes/análise , Expressão Gênica , Compostos de Quinolínio/administração & dosagem , Compostos de Quinolínio/análise , Transgenes
4.
Bioelectrochemistry ; 122: 123-133, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29627664

RESUMO

Bipolar cancellation refers to a phenomenon when applying a second electric pulse reduces ("cancels") cell membrane damage by a preceding electric pulse of the opposite polarity. Bipolar cancellation is a reason why bipolar nanosecond electric pulses (nsEP) cause weaker electroporation than just a single unipolar phase of the same pulse. This study was undertaken to explore the dependence of bipolar cancellation on nsEP parameters, with emphasis on the amplitude ratio of two opposite polarity phases of a bipolar pulse. Individual cells (CHO, U937, or adult mouse ventricular cardiomyocytes (VCM)) were exposed to either uni- or bipolar trapezoidal nsEP, or to nanosecond electric field oscillations (NEFO). The membrane injury was evaluated by time-lapse confocal imaging of the uptake of propidium (Pr) or YO-PRO-1 (YP) dyes and by phosphatidylserine (PS) externalization. Within studied limits, bipolar cancellation showed little or no dependence on the electric field intensity, pulse repetition rate, chosen endpoint, or cell type. However, cancellation could increase for larger pulse numbers and/or for longer pulses. The sole most critical parameter which determines bipolar cancellation was the phase ratio: maximum cancellation was observed with the 2nd phase of about 50% of the first one, whereas a larger 2nd phase could add a damaging effect of its own. "Swapping" the two phases, i.e., delivering the smaller phase before the larger one, reduced or eliminated cancellation. These findings are discussed in the context of hypothetical mechanisms of bipolar cancellation and electroporation by nsEP.


Assuntos
Permeabilidade da Membrana Celular , Eletroporação/métodos , Propídio/farmacocinética , Compostos de Quinolínio/farmacocinética , Animais , Benzoxazóis/administração & dosagem , Benzoxazóis/farmacocinética , Células CHO , Membrana Celular/metabolismo , Células Cultivadas , Cricetulus , Eletricidade , Feminino , Camundongos , Miócitos Cardíacos/metabolismo , Fosfatidilserinas/metabolismo , Propídio/administração & dosagem , Compostos de Quinolínio/administração & dosagem
5.
Bioelectrochemistry ; 121: 135-141, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29413863

RESUMO

Decreasing the time gap between two identical electric pulses is expected to render bioeffects similar to those of a single pulse of equivalent total duration. In this study, we show that it is not necessarily true, and that the effects vary for different permeabilization markers. We exposed individual CHO or NG108 cells to one 300-ns pulse (3.7-11.6 kV/cm), or a pair of such pulses (0.4-1000 µs interval), or to a single 600-ns pulse of the same amplitude. Electropermeabilization was evaluated (a) by the uptake of YO-PRO-1 (YP) dye; (b) by the amplitude of elicited Ca2+ transients, and (c) by the entry of Tl+ ions. For YP uptake, applying a 600-ns pulse or a pair of 300-ns pulses doubled the effect of a single 300-ns pulse; this additive effect did not depend on the time interval between pulses or the electric field, indicating that already permeabilized cells are as susceptible to electropermeabilization as naïve cells. In contrast, Ca2+ transients and Tl+ uptake increased in a supra-additive fashion when two pulses were delivered instead of one. Paired pulses at 3.7 kV/cm with minimal separation (0.4 and 1 µs) elicited 50-100% larger Ca2+ transients than either a single 600-ns pulse or paired pulses with longer separation (10-1000 µs). This paradoxically high efficiency of the closest spaced pulses was emphasized when Ca2+ transients were elicited in a Ca2+-free solution (when the endoplasmic reticulum (ER) was the sole significant source of Ca2+), but was eliminated by Ca2+ depletion from the ER and was not observed for Tl+ entry through the electropermeabilized membrane. We conclude that closely spaced paired pulses specifically target ER, by either permeabilizing it to a greater extent than a single double-duration pulse thus causing more Ca2+ leak, or by amplifying Ca2+-induced Ca2+ release by an unknown mechanism.


Assuntos
Permeabilidade da Membrana Celular , Sistemas de Liberação de Medicamentos/métodos , Eletroporação/métodos , Corantes Fluorescentes/farmacocinética , Compostos de Quinolínio/farmacocinética , Tálio/farmacocinética , Animais , Benzoxazóis/administração & dosagem , Benzoxazóis/farmacocinética , Células CHO , Cálcio/metabolismo , Linhagem Celular Tumoral , Cricetulus , Corantes Fluorescentes/administração & dosagem , Compostos de Quinolínio/administração & dosagem , Ratos , Tálio/administração & dosagem
6.
Neurotox Res ; 29(2): 267-74, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26646154

RESUMO

UNLABELLED: Inhibitors of acetylcholinesterase (AChE) may be used in the treatment of various cholinergic deficits, among them being myasthenia gravis (MG). This paper describes the first in vivo data for promising small quaternary inhibitors (K298 and K524): acute toxicity study, cholinesterase inhibition, absorption, and blood-brain barrier penetration. The newly prepared AChE inhibitors (bis-quinolinium and quinolinium compounds) possess a positive charge in the molecule which ensures that anti-AChE action is restricted to peripheral effect. HPLC-MS was used for determination of real plasma and brain concentration in the pharmacokinetic part of the study, and standard non-compartmental analysis was performed. The maximum plasma concentrations were attained at 30 min (K298; 928.76 ± 115.20 ng/ml) and 39 min (K524; 812.40 ± 54.96 ng/ml) after i.m. APPLICATION: Both compounds are in fact able to target the central nervous system. It seems that the difference in the CNS distribution profile depends on an active efflux system. The K524 brain concentration was actively decreased to below an effective level; in contrast, K298 progressively accumulated in brain tissue. Peripheral AChE inhibitors are still first-line treatment in the mild forms of MG. Commonly prescribed carbamates have many severe side effects related to AChE carbamylation. The search for new treatment strategies is still important. Unlike carbamates, these new compounds target AChE via apparent π-π or π-cationic interaction aside at the AChE catalytic site.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Inibidores da Colinesterase/farmacocinética , Compostos de Quinolínio/farmacocinética , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Química Encefálica/efeitos dos fármacos , Inibidores da Colinesterase/administração & dosagem , Inibidores da Colinesterase/sangue , Inibidores da Colinesterase/toxicidade , Colinesterases/sangue , Dose Letal Mediana , Masculino , Compostos de Quinolínio/administração & dosagem , Compostos de Quinolínio/sangue , Compostos de Quinolínio/toxicidade , Ratos , Ratos Wistar
7.
Mol Cancer Ther ; 14(1): 31-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25487918

RESUMO

Choline kinase α (CHKA; here designated as ChoKα) is the first enzyme in the CDP-choline pathway, implicated in phospholipids metabolism. It is overexpressed in several human tumors such as breast, lung, bladder, colorectal, prostate, ovary, and liver. The overexpression of ChoKα has oncogenic potential and synergizes with other known oncogenes. It has been proposed as a novel cancer drug target with a distinct mechanism of action. We have generated a set of ChoKα inhibitors with potent in vitro antiproliferative and in vivo antitumoral activity against human xenografts in mice, showing high efficacy with low toxicity profiles. Among these inhibitors, RSM-932A has been chosen for further clinical development due to its potent antiproliferative activity in vitro against a large variety of tumor-derived cell lines, a potent in vivo anticancer activity, and lack of toxicity at the effective doses. Here, we provide the preclinical evidence to support the use of RSM-932A as a good candidate to be tested in clinical trials as the "first in humans" drug targeting ChoKα.


Assuntos
Compostos de Anilina/administração & dosagem , Antineoplásicos/administração & dosagem , Colina Quinase/antagonistas & inibidores , Metabolismo dos Lipídeos/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Compostos de Quinolínio/administração & dosagem , Compostos de Anilina/farmacologia , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células HCT116 , Células HT29 , Células HeLa , Células Hep G2 , Humanos , Injeções Intraperitoneais , Camundongos , Neoplasias/metabolismo , Compostos de Quinolínio/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
8.
J Biol Chem ; 288(41): 29974-86, 2013 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-23983125

RESUMO

Direct cellular entry of potentially useful polar compounds into cells is prevented by the hydrophobic barrier of the membrane. Toward circumventing this barrier, we used high throughput screening to identify a family of peptides that carry membrane-impermeant cargos across synthetic membranes. Here we characterize the plasma membrane translocation of these peptides with polar cargos under a variety of conditions. The spontaneous membrane-translocating peptides (SMTPs) delivered the zwitterionic, membrane-impermeant dye tetramethylrhodamine (TAMRA) into cells even when the conditions were not permissive for endocytosis. They also delivered the larger, anionic membrane-impermeant dye Alexa Fluor 546 but did not deliver a quantum dot nanoparticle. Under all conditions, the SMTP-cargo filled the cytoplasm with a diffuse, non-punctate fluorescence that was partially excluded from the nucleus. D-amino acid peptides behaved identically in vitro, ruling out proteolysis as an important factor in the diffuse cellular distribution. Thus, cytosolic delivery of SMTP-cargo conjugates is dominated by direct membrane translocation. This is in sharp contrast to Arg9-TAMRA, a representative highly cationic, cell-penetrating peptide, which entered cells only when endocytosis was permitted. Arg9-TAMRA triggered large scale endocytosis and did not appreciably escape the endosomal compartments in the 1-h timescales we studied. When injected into mice, SMTP-TAMRA conjugates were found in many tissues even after 2 h. Unconjugated TAMRA was rapidly cleared and did not become systemically distributed. SMTPs are a platform that could improve delivery of many polar compounds to cells, in the laboratory or in the clinic, including those that would otherwise be rejected as drugs because they are membrane-impermeant.


Assuntos
Membrana Celular/metabolismo , Citosol/metabolismo , Peptídeos/metabolismo , Rodaminas/metabolismo , Sequência de Aminoácidos , Animais , Transporte Biológico , Células CHO , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Cricetulus , Sistemas de Liberação de Medicamentos/métodos , Endocitose , Feminino , Corantes Fluorescentes/administração & dosagem , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Peptídeos/administração & dosagem , Peptídeos/química , Compostos de Quinolínio/administração & dosagem , Compostos de Quinolínio/química , Compostos de Quinolínio/metabolismo , Reprodutibilidade dos Testes , Rodaminas/administração & dosagem , Rodaminas/química
9.
J Exp Biol ; 216(Pt 19): 3591-8, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23788710

RESUMO

The labeling of specific molecules and their artificial control in living cells are powerful techniques for investigating intracellular molecular dynamics. To use these techniques, molecular compounds (hereinafter described simply as 'samples') need to be loaded into cells. Electroporation techniques are exploited to load membrane-impermeant samples into cells. Here, we developed a new electroporator with four special characteristics. (1) Electric pulses are applied to the adherent cells directly, without removing them from the substratum. (2) Samples can be loaded into the adherent cells while observing them on the stage of an inverted microscope. (3) Only 2 µl of sample solution is sufficient. (4) The device is very easy to use, as the cuvette, which is connected to the tip of a commercially available auto-pipette, is manipulated by hand. Using our device, we loaded a fluorescent probe of actin filaments, Alexa Fluor 546 phalloidin, into migrating keratocytes. The level of this probe in the cells could be easily adjusted by changing its concentration in the electroporation medium. Samples could be loaded into keratocytes, neutrophil-like HL-60 cells and Dictyostelium cells on a coverslip, and keratocytes on an elastic silicone substratum. The new device should be useful for a wide range of adherent cells and allow electroporation for cells on various types of the substrata.


Assuntos
Eletroporação/métodos , Corantes Fluorescentes/administração & dosagem , Compostos de Quinolínio/administração & dosagem , Citoesqueleto de Actina/ultraestrutura , Animais , Movimento Celular , Células Cultivadas , Dictyostelium/citologia , Eletroporação/instrumentação , Desenho de Equipamento , Corantes Fluorescentes/análise , Carpa Dourada , Células HL-60 , Humanos , Queratinócitos/citologia , Microscopia de Fluorescência , Compostos de Quinolínio/análise , Coloração e Rotulagem/instrumentação , Coloração e Rotulagem/métodos
10.
Int J Pharm ; 438(1-2): 191-201, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22960428

RESUMO

To evaluate the effect of different peptides as well as their introduction methods on target gene transfer of gene vectors based on disulfide-containing polyethyleneimine (SS-PEI), a series of peptides including N(3)-GRGDSF, GRGDSF, and EEEEEEEEGRGDSF (E(8)GRGDSF) were prepared. N(3)-GRGDSF was conjugated to SS-PEI by click chemistry and SS-PEI-GRGDSF was obtained. GRGDSF was non-covalently introduced into SS-PEI/DNA mainly through hydrogen bonding to obtain SS-PEI/DNA/GRGDSF complexes, whereas E(8)GRGDSF was further non-covalently introduced to SS-PEI/DNA through electrostatic force to obtain SS-PEI/DNA/E(8)GRGDSF complexes. Transfection efficiency of all complexes with peptides was lower than that of SS-PEI/DNA in COS-7 cells due to the fact that nonspecific endocytosis was prohibited after peptide introduction. Whereas in HeLa cells, transfection activity of SS-PEI-GRGDSF/DNA and SS-PEI/DNA/E(8)GRGDSF at certain w/w ratios was higher than that of SS-PEI/DNA. But the transfection efficiency of SS-PEI/DNA/E(8)GRGDSF at peptide/DNA w/w ratios higher than 30 dropped due to targeted binding interactions between surplus E(8)GRGDSF and the integrins in HeLa cells, which would prohibit specific endocytosis of E(8)GRGDSF in complexes. Transfection activity of SS-PEI/DNA/GRGDSF was lower than or comparable to that of SS-PEI/DNA because of loose complexes constructed by hydrogen bonding between GRGDSF and SS-PEI/DNA.


Assuntos
DNA/administração & dosagem , Peptídeos/administração & dosagem , Polietilenoimina/administração & dosagem , Transfecção/métodos , Animais , Benzimidazóis/administração & dosagem , Benzoxazóis/administração & dosagem , Células COS , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , DNA/química , Dissulfetos/química , Corantes Fluorescentes/administração & dosagem , Vetores Genéticos , Células HeLa , Humanos , Peptídeos/química , Polietilenoimina/química , Compostos de Quinolínio/administração & dosagem
11.
J Control Release ; 160(3): 592-600, 2012 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-22546681

RESUMO

Arginine-grafted bio-reducible poly(disulfide amine) (ABP) was incorporated into the poly(amido amine) (PAMAM) dendrimer, creating a high molecular weight bio-reducible polymer, PAM-ABP, to overcome the limitations of the low molecular weight ABP. The newly synthesized PAM-ABP was studied to determine its efficacy as a gene delivery carrier. The PAM-ABP demonstrated superior condensing ability for plasmid DNA through the formation of compact nanosized polyplexes. These compact polyplexes enhanced cellular uptake and were less susceptible to reducing agents, resulting in greater transfection efficiency compared to ABP alone. Based on these results, this newly developed PAM-ABP polyplex is a promising delivery system for clinical gene therapy.


Assuntos
Arginina/administração & dosagem , Dendrímeros/administração & dosagem , Poliaminas/administração & dosagem , Transfecção/métodos , Animais , Arginina/química , Benzoxazóis/administração & dosagem , Benzoxazóis/química , Butionina Sulfoximina , Linhagem Celular , Sobrevivência Celular , DNA/administração & dosagem , DNA/química , Dendrímeros/química , Proteínas de Fluorescência Verde/administração & dosagem , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/genética , Células HeLa , Humanos , Camundongos , Células NIH 3T3 , Plasmídeos , Poliaminas/química , Compostos de Quinolínio/administração & dosagem , Compostos de Quinolínio/química
12.
Yakugaku Zasshi ; 131(11): 1667-74, 2011.
Artigo em Japonês | MEDLINE | ID: mdl-22041707

RESUMO

We previously reported that oral administration of NK-4, a criptocyanine dye, enhances interleukin (IL)-12-depend- ent interferon (IFN)-γ production by lipopolysaccharide (LPS)-stimulated mouse splenocytes. These findings raised a possibility that NK-4 potentiated IFN-γ production by T cells, natural killer (NK) cells or natural killer T (NKT) cells in response to IL-12 produced by macrophage and dendritic cells. To explore this possibility, we first analyzed percentages of T, NK or NKT cells in splenocytes of mice that were administered NK-4 orally for three days. The percentage of NKT cells in splenocytes from NK-4-treated mice was significantly (p<0.05) increased compared to vehicle-treated mice. When splenocytes were stimulated with α-galactosylceramide (α-GalCer), an NKT cell ligand, IFN-γ production by splenocytes from NK-4-treated mice tended to increase, while no difference in the IL-4 production and proliferation were observed between the vehicle- and NK-4-treated mice. When IFN-γ/IL-4 ratios were calculated in individual mice, the ratios were significantly (p<0.05) elevated in NK-4-treated mice. Furthermore, IL-12 production by α-GalCer-stimulated splenocytes from NK-4-treated mice was also significantly (p<0.05) increased. These results suggest that oral administration of NK-4 increases the population of type I NKT cells with potent IFN-γ-producing activities. Since IL-12 and IFN-γ have been shown to play important roles in anti-tumor immunity as well as in the defence against bacterial infection, our results further imply that NK-4 may provide a potential therapeutic tool in cancer immunotherapy.


Assuntos
Corantes/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Células T Matadoras Naturais/imunologia , Compostos de Quinolínio/farmacologia , Administração Oftálmica , Animais , Antineoplásicos , Células Cultivadas , Corantes/administração & dosagem , Feminino , Galactosilceramidas/farmacologia , Interferon gama/biossíntese , Interleucina-12/biossíntese , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , Compostos de Quinolínio/administração & dosagem , Baço/citologia , Estimulação Química
13.
Hypertension ; 57(6): 1129-35, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21502564

RESUMO

We have shown previously that inhibition of small conductance Ca(2+)-activated K(+) (SK) channels is antiarrhythmic in models of acutely induced atrial fibrillation (AF). These models, however, do not take into account that AF derives from a wide range of predisposing factors, the most prevalent being hypertension. In this study we assessed the effects of two different SK channel inhibitors, NS8593 and UCL1684, in aging, spontaneously hypertensive rats to examine their antiarrhythmic properties in a setting of hypertension-induced atrial remodeling. Male spontaneously hypertensive rats and the normotensive Wistar-Kyoto rat strain were divided in 2×3 groups of animals aged 3, 8, and 11 months, respectively. The animals were randomly assigned to treatment with NS8593, UCL1684, or vehicle, and open chest in vivo experiments including burst pacing-induced AF were performed. The aging spontaneously hypertensive rats were more vulnerable to AF induction both by S2 stimulation and burst pacing. Vehicle affected neither the atrial effective refractory period nor AF duration. SK channel inhibition with NS8593 and UCL1684 significantly increased the atrial effective refractory period and decreased AF duration in both the normotensive and hypertensive strains with no decline in efficacy as age increased. In conclusion, SK channel inhibition with NS8593 and UCL1684 possesses antiarrhythmic properties in a rat in vivo model of paroxysmal AF with hypertension-induced atrial remodeling. The present results support the notion that SK channels may offer a promising new therapeutic target in the treatment of AF.


Assuntos
Fibrilação Atrial/prevenção & controle , Hipertensão/fisiopatologia , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio Cálcio-Ativados/antagonistas & inibidores , 1-Naftilamina/administração & dosagem , 1-Naftilamina/análogos & derivados , 1-Naftilamina/farmacologia , Fatores Etários , Alcanos/administração & dosagem , Alcanos/farmacologia , Animais , Antiarrítmicos/administração & dosagem , Antiarrítmicos/farmacologia , Fibrilação Atrial/fisiopatologia , Estimulação Cardíaca Artificial , Modelos Animais de Doenças , Humanos , Injeções Intravenosas , Masculino , Bloqueadores dos Canais de Potássio/administração & dosagem , Canais de Potássio Cálcio-Ativados/fisiologia , Compostos de Quinolínio/administração & dosagem , Compostos de Quinolínio/farmacologia , Distribuição Aleatória , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Especificidade da Espécie , Fatores de Tempo
14.
Cancer Res ; 67(9): 4418-24, 2007 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-17483356

RESUMO

The delivery of anticancer therapeutics to solid tumors remains a critical problem in the treatment of cancer. This study reports a new methodology to target a temperature-responsive macromolecular drug carrier, an elastin-like polypeptide (ELP) to solid tumors. Using a dorsal skin fold window chamber model and intravital laser scanning confocal microscopy, we show that the ELP forms micron-sized aggregates that adhere to the tumor vasculature only when tumors are heated to 41.5 degrees C. Upon return to normothermia, the vascular particles dissolve into the plasma, increasing the vascular concentration, which drives more ELPs across the tumor blood vessel and significantly increases its extravascular accumulation. These observations suggested that thermal cycling of tumors would increase the exposure of tumor cells to ELP drug carriers. We investigated this hypothesis in this study by thermally cycling an implanted tumor in nude mice from body temperature to 41.5 degrees C thrice within 1.5 h, and showed the repeated formation of adherent microparticles of ELP in the heated tumor vasculature in each thermal cycle. These results suggest that thermal cycling of tumors can be repeated multiple times to further increase the accumulation of a thermally responsive polymeric drug carrier in solid tumors over a single heat-cool cycle. More broadly, this study shows a new approach--tumor thermal cycling--to exploit stimuli-responsive polymers in vivo to target the tumor vasculature or extravascular compartment with high specificity.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Sistemas de Liberação de Medicamentos , Elastina/farmacocinética , Hipertermia Induzida/métodos , Peptídeos/farmacocinética , Animais , Carcinoma de Células Escamosas/irrigação sanguínea , Terapia Combinada , Elastina/sangue , Elastina/química , Humanos , Hidrazinas/administração & dosagem , Hidrazinas/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Peptídeos/sangue , Peptídeos/química , Compostos de Quinolínio/administração & dosagem , Compostos de Quinolínio/farmacocinética
15.
Trop Anim Health Prod ; 29(4 Suppl): 64S-65S, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9512747

RESUMO

From June to August in 1988, a total of 64 pure-bred Landrace, Yorkshire (large white) and Inner Mongolian Black Swine from a farm in Huhehot were affected with a disease, 13 died. The pathogen was confirmed primarily to be Babesia perroncitoi. The drugs used for treatment were Berenil and Acaprin. The intramuscular dose for Berenil was 3 mg per kilogram weight. The subcutaneous dose for Acaprin was 0.8 mg per kilogram weight. All of which had satisfactory results. In the same season in the second year and the third year, the disease was also reported, but all sick animals were cured.


Assuntos
Antiprotozoários/uso terapêutico , Babesiose/tratamento farmacológico , Diminazena/análogos & derivados , Compostos de Quinolínio/uso terapêutico , Doenças dos Suínos/tratamento farmacológico , Ureia/análogos & derivados , Animais , Antiprotozoários/administração & dosagem , China , Diminazena/administração & dosagem , Diminazena/uso terapêutico , Compostos de Quinolínio/administração & dosagem , Suínos , Ureia/administração & dosagem , Ureia/uso terapêutico
16.
Reprod Fertil Dev ; 7(1): 51-7, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7569056

RESUMO

The effects of a number of platelet-activating factor (PAF)-antagonists on embryo implantation were investigated. Mice were treated from Day 1 to Day 4 of pregnancy with three defined PAF-antagonists: SRI 63 441, BN 52021, and WEB 2086. Necroscopies were performed on Day 8 and the number of implantation sites, the implantation rate (number of implanted embryos compared with the number of corpora lutea) and the proportion of animals pregnant were determined. Each agent caused a reduction in the number of implantation sites at relatively low doses. The dose that had a maximum contragestational effect was 40 micrograms, 10 micrograms and 10 micrograms (per 30 g bodyweight per day) for SRI 63 441, WEB 2086 and BN 52021 respectively. This contragestational effect was completely lost at twice (SRI 63 441), five times (WEB 2086) and ten times (BN 52021) the most effective dose. Treatment with WEB 2086 on the day of implantation (Day 4) by intraperitoneal injection or instillation into the uterus only did not significantly reduce the implantation rate and neither did treatment after implantation (Days 5-8). The results show that the pharmacology of PAF-antagonists in early pregnancy is not simple. An understanding of the actions of these agents in early pregnancy will require a detailed knowledge of their pharmacokinetics, pharmacodynamics and targets of action in early pregnancy.


Assuntos
Azepinas/administração & dosagem , Diterpenos , Implantação do Embrião/efeitos dos fármacos , Lactonas/administração & dosagem , Inibidores da Agregação Plaquetária/administração & dosagem , Compostos de Quinolínio/administração & dosagem , Triazóis/administração & dosagem , Animais , Relação Dose-Resposta a Droga , Feminino , Ginkgolídeos , Injeções Intraperitoneais , Camundongos , Gravidez , Fatores de Tempo
17.
Ann Surg ; 209(2): 200-10, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2916864

RESUMO

The present study evaluated and compared the effects of SRI 63-441, a potent platelet activating factor antagonist, superoxide dismutase (SOD), an oxygen free radical scavenger, and ibuprofen, a cyclooxygenase inhibitor on hepatic function after 90 minutes of warm ischemia. After warm ischemia, livers were harvested and underwent 90 minutes of warm, oxygenated, sanguinous perfusion on an isolated liver perfusion apparatus. Pretreatment of donor animals with 20 mg/kg intravenous (I.V.) SRI 63-441 5 minutes before induction of total hepatic ischemia resulted in significantly increased bile production, a significant decrease in transaminase release, and a higher tissue adenosine triphosphate (ATP) content when compared with ischemic nontreated controls. SOD resulted in improved bile production and decreased transaminase liberation only when present in the perfusate at the time of in vitro reperfusion. Ibuprofen did not improve postischemic hepatic function in this model. Electron microscopy revealed patchy hepatocellular vacuolization with an intact sinusoidal endothelium in all ischemic livers. However, the degree of damage was less severe in the livers from those rats pretreated with 20 mg/kg SRI 63-441. This study demonstrates that SRI 63-441 pretreatment significantly reduces hepatic warm ischemic injury, and in the present model, appears superior to two other agents that have been advanced in the treatment of ischemic injury. The use of such agents singly or in combinations have important implications as regards gaining a better understanding of the basic mechanisms in organ ischemia, and moreover, for therapeutic applications in organ ischemia and preservation.


Assuntos
Ibuprofeno/uso terapêutico , Isquemia/etiologia , Fígado/irrigação sanguínea , Fator de Ativação de Plaquetas/antagonistas & inibidores , Compostos de Quinolínio/uso terapêutico , Traumatismo por Reperfusão/prevenção & controle , Superóxido Dismutase/uso terapêutico , Animais , Bile/metabolismo , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Temperatura Alta , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/fisiologia , Fígado/ultraestrutura , Masculino , Microscopia Eletrônica , Perfusão , Compostos de Quinolínio/administração & dosagem , Ratos , Ratos Endogâmicos , Superóxido Dismutase/administração & dosagem , Transaminases/metabolismo
19.
Ann Surg ; 206(4): 482-95, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3310931

RESUMO

The pathogenesis of hyperacute renal rejection consists of a nonspecific effector cascade that invokes most of the components of a typical acute inflammatory response. Platelet-activating factor (PAF) represents the most recent and perhaps the most significant mediator and promoting agent of this phenomenon. These studies evaluated SRI 63-441, a novel, synthetic, and the most potent PAF receptor antagonist available, alone and in combination with other prostanoids, for their ability to influence this response and to prolong renal xenograft survival and function in a model of pig-to-dog heterotransplantation. Inhibition of PAF by SRI 63-441 alone, at the dosage and schedule used in these experiments, did not significantly prolong xenograft survival or function. However, the combination of SRI 63-441 with either prostacyclin (PGI2) or prostaglandin E1 (PGE1) infusion demonstrated significant synergism, and resulted in a 6-9-fold increase in kidney survival and a 3-20-fold increase in urine output. Neither PGI2 nor PGE1 infusions alone significantly influenced this xenograft model. Electromagnetic flow studies demonstrated significantly delayed diminution in renal artery blood flow in the combination-treated animals. Serial and end-stage histologic examination of kidneys receiving combination therapy demonstrated a delayed onset of the pathologic deterioration and an overall amelioration of the entire process. These studies demonstrate that significant abrogation of a rapid and violent form of hyperacute rejection can be achieved solely by the pharmacologic manipulation of the inflammatory mediator response.


Assuntos
Sobrevivência de Enxerto/efeitos dos fármacos , Transplante de Rim , Fator de Ativação de Plaquetas/antagonistas & inibidores , Compostos de Quinolínio/farmacologia , Transplante Heterólogo , Alprostadil/administração & dosagem , Alprostadil/farmacologia , Animais , Biópsia , Cães , Epoprostenol/administração & dosagem , Epoprostenol/farmacologia , Feminino , Inflamação/fisiopatologia , Rim/patologia , Masculino , Fator de Ativação de Plaquetas/fisiologia , Contagem de Plaquetas , Compostos de Quinolínio/administração & dosagem , Circulação Renal , Suínos
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