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Agrimonia pilosa (AP), Galla rhois (RG), and their mixture (APRG64) strongly inhibited SARS-CoV-2 by interfering with multiple steps of the viral life cycle including viral entry and replication. Furthermore, among 12 components identified in APRG64, three displayed strong antiviral activity, ursolic acid (1), quercetin (7), and 1,2,3,4,6-penta-O-galloyl-ß-d-glucose (12). Molecular docking analysis showed these components to bind potently to the spike receptor-binding-domain (RBD) of the SARS-CoV-2 and its variant B.1.1.7. Taken together, these findings indicate APRG64 as a potent drug candidate to treat SARS-CoV-2 and its variants.
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Agrimonia/química , Antivirales/química , Productos Biológicos/química , Tratamiento Farmacológico de COVID-19 , Extractos Vegetales/química , SARS-CoV-2/efectos de los fármacos , Secuencia de Aminoácidos , Antivirales/farmacología , Productos Biológicos/farmacología , Descubrimiento de Drogas , Humanos , Taninos Hidrolizables/química , Simulación del Acoplamiento Molecular , Extractos Vegetales/farmacología , Unión Proteica , Quercetina/química , Glicoproteína de la Espiga del Coronavirus/química , Triterpenos/química , Internalización del Virus/efectos de los fármacos , Ácido UrsólicoRESUMEN
BACKGROUND: Hypoxia inhibits the uptake of glutamate (a major neurotransmitter in the brain closely related to cognitive function) into brain cells, and the initial response of cells to cortical hypoxia depends on glutamate. Previous studies have suggested that magnesium may have protective effects against hypoxic injuries. In particular, magnesium L-threonate (MgT) may increase magnesium ion concentrations in the brain better than MgSO4 and improve cognitive function. METHODS: We evaluated cell viability under hypoxic conditions in the MgT- and MgSO4-treated human SH-SY5Y neurons, in vivo behavior using the T-maze test following hypoxia in MgT-treated zebrafish, activity of brain mitochondrial dehydrogenase by 2,3,5-triphenyltetrazolium chloride (TTC) staining, and protein expression of the excitatory amino acid transporter (EAAT) 4 glutamate transporter by western blotting. RESULTS: Among the groups treated with hypoxia, cell viability significantly increased when pre-treated with 1 or 10 mM MgT (p = 0.009 and 0.026, respectively). Despite hypoxic insult, MgT-treated zebrafish showed preferences for the red compartment (p = 0.025 for distance and p = 0.007 for frequency of entries), suggesting memory preservation. TTC staining showed reduced cerebral infarction and preserved absorbance in the MgT-treated zebrafish brain after hypoxia (p = 0.010 compared to the hypoxia group). In addition, western blot showed upregulation of EAAT4 protein in the MgT treated group. CONCLUSIONS: Pre-treatment with MgT attenuated cell death and cerebral infarction due to hypoxia and protected cognitive function in zebrafish. In addition, MgT appeared to modulate expression of the glutamate transporter, EAAT4.
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Encéfalo/efectos de los fármacos , Butiratos/farmacología , Hipoxia/fisiopatología , Magnesio/metabolismo , Fármacos Neuroprotectores/farmacología , Animales , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Ácido Glutámico/metabolismo , Hipoxia/tratamiento farmacológico , Magnesio/farmacología , Memoria/efectos de los fármacos , Memoria/fisiología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Pez Cebra/metabolismoRESUMEN
BACKGROUND: Sugammadex is a new neuromuscular blockade reversal agent. Recently, it has been used in patients under general anesthesia. However, sugammadex could be toxic to fetuses and pediatric patients under 3 years of age. In this study, we demonstrated the safety of sugammadex in fetuses, using zebrafish larvae. Furthermore, its neurotoxicity was evaluated using neuronal cell lines. METHODS: We used SH-SY5Y cells to determine the viability of neuronal cells treated with sugammadex. Zebrafish larvae were used to determine the teratogenic effects of sugammadex. RESULTS: Sugammadex showed no adverse effects on neuronal cells and zebrafish larvae. The survival rates of neuronal cells were not different in all concentrations. In addition, the heart formation of zebrafish embryos, which were exposed to various concentrations of sugammadex, were not different. CONCLUSION: This study demonstrated the feasibility of using sugammadex during pregnancy. However, further clinical studies will be required to extrapolate these results to humans.
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Larva/efectos de los fármacos , Sugammadex/toxicidad , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Embrión no Mamífero/efectos de los fármacos , Corazón/anatomía & histología , Corazón/efectos de los fármacos , Humanos , Larva/anatomía & histología , Pez Cebra/crecimiento & desarrolloRESUMEN
The objective of this study was to investigate the effects of dietary corticosterone on egg quality. For 2 weeks hens received either control or experimental diet containing corticosterone at 30 mg/kg diet. Feed intake and egg production were monitored daily, and body weight measured weekly. Egg weights and egg quality were measured daily. Corticosterone treatment resulted in a remarkable increase in feed intake and sharp decrease in egg production compared with control (p<0.05) whereas body weight remained unchanged. Decreased albumen height, but no changes in egg weight, led to decreased Haugh unit (p<0.05). Corticosterone caused elevated eggshell thickness (p<0.05) without altering weight and strength, suggesting possible changes in shell structure. Yolk color and redness were increased by corticosterone (p<0.05) but lightness and yellowness were either not changed or inconsistent over the time period of measurements. Increased concentrations in plasma were also found for corticosterone, glucose, cholesterol, creatinine, uric acid, albumin, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, total protein, and amylase (p<0.05), suggesting that corticosterone increased protein breakdown, renal dysfunctions and pancreatitis. Together, the current results imply that dietary corticosterone affects egg quality such as yolk colors and shell thickness, in addition to its effects on feed intake and egg production.
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Previous study indicated that Ulinastatin (UTI) increased glutamine uptake by upregulation of glutamate transporters in astrocytes. These glutamate transporters have important role to improve cognitive function in hippocampus. In this study, we wanted to demonstrate whether UTI could improve learning and memory by using zebrafish behavior model and bio-markers. Zebrafish were 6-8 months of age and were 2.5-3.5 cm long. They were divided into four groups by control, 1X PBS-injected control, UTI 10,000, and 50,000 injected group. All PBS and UTI injected zebrafish were anesthetized by Tricainemethanesulphonate. We measured total time, distance moved, and frequency in each compartment of T-maze. We also measured the expression levels of glutamate transporter levels and cognitive bio-markers such as c-fos, c-jun, BDNF. UTI affected the learning and memory in zebrafish in a dose-dependent manner. In 50,000 unit/kg UTI-treated zebrafish, there were increases of time, distance, and frequency in target compartment. In 50,000 unit/kg UTI-treated zebrafish, there was an increase of time in target compartment. There was no difference among control, PBS-injected, and UTI 10,000 unit/kg-treated groups. EAAT4 glutamate transporter, c-fos and BDNF were significantly increased in 50,000 unit/kg UTI-treated group. UTI-enhanced learning and memory in zebrafish. The expressions of EAAT4 glutamate transporter, c- fos and BDNF in zebrafish were highly correlated may play a role.
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Glicoproteínas , Pez Cebra , Animales , Astrocitos , HipocampoRESUMEN
Perioperative brain ischemia and stroke are leading causes of morbidity and mortality. Brief hypoxic preconditioning is known to have protective effects against hypoxic-ischemic insult in the brain. Current studies on the neuroprotective effects of ischemic preconditioning are based on histologic findings and biomarker changes. However, studies regarding effects on memory are rare. To precondition zebrafish to hypoxia, they were exposed to a dissolved oxygen (DO) concentration of 1.0 ± 0.5â mg/L in water for 30â s. The hypoxic zebrafish were then exposed to 1.0 ± 0.5â mg/L DO until the third stage of hypoxia, for 10 min ± 30â s. Zebrafish were assessed for memory retention after the hypoxic event. Learning and memory were tested using the T-maze, which evaluates memory based on whether or not zebrafish moves to the correct target compartment. In the hypoxic preconditioning group, infarct size was reduced compared with the hypoxic-only treated zebrafish group; memory was maintained to a degree similar to that in the hypoxia-untreated group. The hypoxic-only group showed significant memory impairments. In this study, we used a hypoxic zebrafish model and assessed the effects of ischemic preconditioning not only on histological damages but also on brain function, especially memory. This study demonstrated that a brief hypoxic event has protective effects in hypoxic brain damage and helped maintain memory in zebrafish. In addition, our findings suggest that the zebrafish model is useful in rapidly assessing the effects of ischemic preconditioning on memory.
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Epidermal growth factor (EGF) accelerates the re-epithelialization of damaged epidermal cell layers in a wound, so it especially shortens the duration of wound healing. The effect of EGF on pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and cyclooxygenase-2 (COX-2), levels during wound healing has not been reported. We investigated the relationship between exogenous EGF treatment and the expression of TNF-alpha and COX-2 mRNA in porcine split-thickness wounds by real-time PCR. Twenty split-thickness wounds were created on the back of five pigs. Fifteen wounds were treated twice daily with EGF ointments (1 microg/g, 10 microg/g, and 50 microg/g) for 10 days and five wounds were untreated. Healing time until full-epithelialization was evaluated. We performed a quantitative analysis of TNF-alpha and COX-2 mRNA expression in wound biopsies using real-time PCR. Topical application of 1 microg/g EGF accelerated re-epithelialization more than treatments of EGF at 10 microg/g and 50 microg/g, and no treatment. The levels of TNF-alpha and COX-2 mRNA were significantly greater in wounds treated with 1 microg/g than those with 10 microg/g and 50 microg/g EGF, and no treatment. Topical treatment of EGF influences the level of TNF-alpha and COX-2 mRNA within porcine split-thickness wounds. EGF-dependent slightly up-regulation of TNF-alpha and COX-2 mRNA expression during the inflammatory phase of healing may create an optimal molecular environment for wound healing.
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Ciclooxigenasa 2/genética , Factor de Crecimiento Epidérmico/uso terapéutico , Regulación de la Expresión Génica/efectos de los fármacos , Enfermedades de los Porcinos/tratamiento farmacológico , Enfermedades de los Porcinos/genética , Factor de Necrosis Tumoral alfa/genética , Cicatrización de Heridas/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Reacción en Cadena de la Polimerasa/veterinaria , ARN Mensajero/genética , ARN Mensajero/metabolismo , Porcinos , Cicatrización de Heridas/genética , Heridas y Lesiones/tratamiento farmacológico , Heridas y Lesiones/genética , Heridas y Lesiones/veterinariaRESUMEN
The steamed root of Rehmannia glutinosa has been used in traditional Oriental Medicine for treatment of inner ear diseases, such as tinnitus and hearing loss. In the present study, we showed that the ethanol extract of steamed roots of Rehmannia glutinosa (SRG) protected HEI-OC1 auditory cells from cisplatin cytotoxicity in a dose-dependent fashion. In addition, to investigate the protection mechanism of SRG on cisplatin cytotoxicity towards HEI-OC1, we measured the effects of SRG on lipid peroxidation of cisplatin treated cells as well as scavenging activities against superoxide radical, hydroxyl radical, hydrogen peroxide, and DPPH radical. SRG (5-100 microg/ml) had protective effect against the cisplatin-induced HEI-OC1 cell damage and reduced lipid peroxidation in a dose-dependent manner. Furthermore, SRG showed strong scavenging activity against superoxide radical, hydroxyl radical, hydrogen peroxide, and DPPH radical. These results indicate that SRG protects cisplatin-induced HEI-OC1 cell damage through inhibition of lipid peroxidation and scavenging activities of free radials.
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Antineoplásicos/toxicidad , Cisplatino/toxicidad , Cóclea/efectos de los fármacos , Depuradores de Radicales Libres/farmacología , Rehmannia , Animales , Compuestos de Bifenilo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cóclea/citología , Cóclea/metabolismo , Relación Dosis-Respuesta a Droga , Depuradores de Radicales Libres/química , Peróxido de Hidrógeno/química , Radical Hidroxilo/química , Peroxidación de Lípido/efectos de los fármacos , Picratos/química , Extractos Vegetales/farmacología , Raíces de Plantas , Superóxidos/químicaRESUMEN
Steamed roots of Rehmannia glutinosa (R. glutinosa) have been traditionally used in Oriental medicine for the treatment of auditory diseases such as tinnitus and hearing loss. To investigate whether the ethanol extract of steamed roots of R. glutinosa (SRG) increases activity of antioxidant enzymes and the level of glutathione (GSH), we measured activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GR) and GSH level in HEI-OC1 cells after treatment with 5-50 microg/ml of SRG. The SOD and CAT activities were significantly increased in the presence of SRG compared to the control group. Maximal activities of SOD and CAT were observed in these cells exposed to 10 microg/ml of SRG. The GPX activity also increased dramatically in response to the treatment with SRG in a dose-dependent manner. The GR activity was only increased in the presence of 50 microg/ml of SRG compared to the control group. The level of GSH gradually increased in the presence of 5-50 microg/ml of SRG. In the cytotoxicity test, 5-50 microg/ml of SRG did not show any significant cytotoxicity. These results suggest that the traditional use of R. glutinosa for the treatment of auditory diseases may be explained, in part, by activation of intracellular antioxidant enzyme systems. Further studies are necessary to clarify the active constituents of SRG responsible for such biomolecular activities.
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Células Ciliadas Auditivas/metabolismo , Oxidorreductasas/biosíntesis , Rehmannia , Animales , Línea Celular , Células Ciliadas Auditivas/citología , Ratones , Raíces de PlantasRESUMEN
BACKGROUND: Ischemic insults during operation can cause ischemic-reperfusion injuries in brain as well as memory impairments. Total intravenous anesthesia (TIVA) is the preferred anesthetic method in brain surgery, as it utilizes motor evoked potential monitoring. And the use of opioids is common in TIVA. However there are few studies about ischemic protective effect of opioids to glial cells. METHODS: We used mixed cultures of rat glial cells, which were harvested from the brain of 1-day old rat. We divided the experimental groups according to their hydromorphone conditioning period: (a) pre-culture, (b) per-culture, or (c) pre- and per-culture. We measured the levels of the reactive oxygen species (ROS) induced by tert-butyl hydroperoxide (TBH) using flow cytometry. The ROS levels in the glial cells were also measured after the administration of 100 nM hydromorphone and selective opioid receptor antagonists. RESULTS: The ROS levels were reduced in the hydromorphone-treated group, as compared to the control group (only TBH treated). There were no differences between pre-conditioned and per-conditioned groups. However, the ROS levels were more reduced in pre- and per-conditioned group compared to pre-conditioned or per-conditioned only groups. Furthermore, selective antagonists for the delta, kappa, or mu opioid receptor partially negated the hydromorphone effect. CONCLUSION: This study demonstrated that hydromorphone can have additional protective effects on oxidative stress when pre- and per-conditioning is combined. Furthermore we proved that µ, δ, κ opioid receptors participate in protective mechanism of hydromorphone to glial cells.
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Valproic acid (VPA) is used as an antiepileptic drug (AED) or mood stabilizer. Recent studies have shown that exposure to VPA during embryonic development alters neural progenitor cell (NPC) proliferation, and can also lead to behavioral impairment in adult animals. The main goal of this investigation was to evaluate the effects of treatment with 2 mM VPA for 3h on cell proliferation in the telencephalic area of zebrafish larvae of 5 days post-fertilization (dpf) using immunohistochemistry (IHC). It was also determined whether VPA exposure affects the learning ability and anxiety levels of zebrafish during adulthood using bottom-dwelling behavior and passive avoidance tests. Result of the study demonstrated that VPA exposure during development transiently decreased neuronal cell proliferation without inducing apoptosis. Additionally, quantitative real-time PCR (qRT-PCR) data indicated that mRNA expression levels of wnt signaling pathway-related factors such as ß-catenin, lef1, and gsk3ß were altered in the zebrafish treated with VPA. Interestingly, these effects were reversed over time after VPA treatment had ceased. Alterations of passive avoidance learning and bottom dwelling behavior were not observed during adulthood after developmental VPA exposure. These results may be due to the restoration of cell proliferation during the recovery period after VPA treatment.
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Anticonvulsivantes/toxicidad , Proliferación Celular/efectos de los fármacos , Neurogénesis/efectos de los fármacos , Telencéfalo/citología , Telencéfalo/efectos de los fármacos , Ácido Valproico/toxicidad , Pez Cebra/crecimiento & desarrollo , Animales , Reacción de Prevención/efectos de los fármacos , Larva/citología , Larva/efectos de los fármacos , Células Madre/citología , Células Madre/efectos de los fármacos , Telencéfalo/fisiopatología , Vía de Señalización Wnt/efectos de los fármacos , Vía de Señalización Wnt/fisiologíaRESUMEN
Non-protein amino acid, ß-amino-n-butyric acid (BABA), has been involved in diverse physiological processes including seedling growth, stress tolerance and disease resistance of many plant species. In the current study, treatment of kimchi cabbage seedlings with BABA significantly reduced primary root elongation and cotyledon development in a dose-dependent manner, which adverse effects were similar to the plant response to exogenous abscisic acid (ABA) application. BABA was synergistically contributing ABA-induced growth arrest during the early seedling development. Kimchi cabbage leaves were highly damaged and seedling growth was delayed by foliar spraying with high concentrations of BABA (10 to 20 mM). BABA played roles differentially in in vitro fungal conidial germination, mycelial growth and conidation of necrotroph Alternaria brassicicola causing black spot disease and hemibiotroph Colletotrichum higginsianum causing anthracnose. Pretreatment with BABA conferred induced resistance of the kimchi cabbage against challenges by the two different classes of fungal pathogens in a dose-dependent manner. These results suggest that BABA is involved in plant development, fungal development as well as induced fungal disease resistance of kimchi cabbage plant.
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Reactive oxygen species (ROS) generation in tomato plants by Ralstonia solanacearum infection and the role of hydrogen peroxide (H2O2) and nitric oxide in tomato bacterial wilt control were demonstrated. During disease development of tomato bacterial wilt, accumulation of superoxide anion (O2 (-)) and H2O2 was observed and lipid peroxidation also occurred in the tomato leaf tissues. High doses of H2O2and sodium nitroprusside (SNP) nitric oxide donor showed phytotoxicity to detached tomato leaves 1 day after petiole feeding showing reduced fresh weight. Both H2O2and SNP have in vitro antibacterial activities against R. solanacearum in a dose-dependent manner, as well as plant protection in detached tomato leaves against bacterial wilt by 10(6) and 10(7) cfu/ml of R. solanacearum. H2O2- and SNP-mediated protection was also evaluated in pots using soil-drench treatment with the bacterial inoculation, and relative 'area under the disease progressive curve (AUDPC)' was calculated to compare disease protection by H2O2 and/or SNP with untreated control. Neither H2O2 nor SNP protect the tomato seedlings from the bacterial wilt, but H2O2+ SNP mixture significantly decreased disease severity with reduced relative AUDPC. These results suggest that H2O2 and SNP could be used together to control bacterial wilt in tomato plants as bactericidal agents.
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Below the knee (BTK) interventions are increasing in patients with rest pain or critical limb ischemia, and these interventions are frequently successful in facilitating limb salvage. New intervention techniques and devices allow successful recanalization of occluded BTK arteries. Here, we report a case of successful recanalization of BTK arteries using multidisciplinary methods, including an antegrade approach and retrograde approach without the use of a sheath, but with simple balloon angioplasty, and plaque excision using Silverhawk atherectomy device.
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2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), one of the components of Agent Orange, has been reported to be a deadly poison despite its presence at extremely small doses. TCDD is reported to cause various kinds of cancers and other harmful effects on humans. However, a correlation between exposure to TCDD and acute coronary syndrome (ACS) is not yet proven. Thus, we examined the correlation between exposure to TCDD and ACS through an analysis of coronary angiograms from veterans of the Vietnam War. Two hundred fifty-one consecutive men undergoing coronary angiograms owing to ACS between April 2004 and May 2009 at Gwangju Veterans Hospital were analyzed. Included subjects were between 50 and 70 years of age. The patients were divided into two groups: 121 patients who had been exposed to TCDD (Group I) and 130 patients who had not been exposed to TCDD (Group II). Clinical and coronary angiographic findings were evaluated. Baseline clinical characteristics, inflammatory markers, and echocardiographic parameters were not significantly different between the two groups. The incidence of hypertension (71.1% vs. 60.0%, p=0.039) and hyperlipidemia (27.3% vs. 16.9%, p=0.038) was higher in Group I than in Group II. Total occlusion, stent length, stent use, and coronary lesion characteristics were not significantly different between the two groups. The rate of major adverse cardiovascular events (MACE) had no relationship with exposure to TCDD. Exposure to TCDD might not affect severity or the rate of MACE in persons with ACS.
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Passage failure of guidewire is still remained most common reason for percutaneous coronary intervention (PCI) failure in chronic total occlusion (CTO). Intravascular ultrasound study (IVUS) and cardiac CT angiography can help identify features that most influence current success rates of PCI. We report our experience using the reverse controlled antegrade and retrograde subintimal tracking technique under the aid of IVUS, cardiac CT angiography for an ambiguous CTO of proximal right coronary artery.
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A 42-year-old male patient presented with refractory hypertension and congestive heart failure. He had taken hydrochlorthiazide 50 mg, carvedilol 25 mg, diltiazem 180 mg, and losartan 100 mg per day. Aortogram revealed a severe luminal narrowing in the distal thoracic aorta with a peak systolic pressure gradient of 60 mmHg across the lesion. Endovascular management was performed with 22 × 80 mm self-expandable Nitinol-S stent after predilation with 10 × 40 mm balloon. After endovascular management, the patient's blood pressure, left ventricular ejection fraction (LVEF) and dilated LV dimension were remarkably improved.
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Pentylenetetrazol (PTZ) has been shown to induce seizure-like behavior, learning deficits in passive avoidance response test, and an increase in hsp70 (heat shock protein 70) mRNA expression in the adult zebrafish; PTZ has been increasingly appreciated as an excellent model system for the study of seizures. In this study, we demonstrate that valproic acid (VPA), an antiepileptic drug, suppresses seizure-like behavior and improves learning ability in adult zebrafish treated with PTZ. Pretreatment with VPA significantly reduces rapid involuntary movement and abrupt changes in moving direction in the PTZ-treated zebrafish. PTZ-induced learning impairments were also improved in the zebrafish pretreated with 200 or 500 microM VPA. However, the scopolamine-induced impairments of learning ability were not improved by VPA pretreatment. It is worth noting that while the zebrafish treated with 500 microM VPA for 1-3 weeks learned the passive avoidance response, those treated with 1 or 2mM VPA for 3h didn't. Furthermore, the increased level of hsp70 expression induced by PTZ, a stress marker protein, was significantly reduced in the VPA-pretreated zebrafish brains. Collectively, our data show the antiepileptic effects of VPA in the adult zebrafish, which coincides with reduced hsp70 mRNA expression, rescued learning impairment under PTZ-treated conditions.
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Anticonvulsivantes/uso terapéutico , Discapacidades para el Aprendizaje/prevención & control , Fármacos Neuroprotectores/uso terapéutico , Pentilenotetrazol/toxicidad , Ácido Valproico/uso terapéutico , Animales , Anticonvulsivantes/administración & dosificación , Reacción de Prevención/efectos de los fármacos , Conducta Animal/efectos de los fármacos , Encéfalo/metabolismo , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Discinesia Inducida por Medicamentos/prevención & control , Regulación de la Expresión Génica/efectos de los fármacos , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Discapacidades para el Aprendizaje/inducido químicamente , Locomoción/efectos de los fármacos , Antagonistas Muscarínicos/toxicidad , Fármacos Neuroprotectores/administración & dosificación , ARN Mensajero/metabolismo , Escopolamina/toxicidad , Convulsiones/inducido químicamente , Convulsiones/prevención & control , Factores de Tiempo , Ácido Valproico/administración & dosificación , Pez CebraRESUMEN
Seizures have been reported to modify neural development in the immature brain. In this study, we attempted to determine whether pentylenetetrazol (a GABAergic receptor antagonist, PTZ)-induced seizures influence cell proliferation in zebrafish larvae (5 and 15 days of post-fertilization), using bromodeoxyuridine (BrdU) to label dividing cells. In the brains of 5 dpf larvae, PTZ treatment significantly reduced the number of BrdU-labeled cells in the telencephalic area (pallium and subpallium), diencephalic area (thalamus and preoptic area), medial tectal proliferation zone, and medial cerebellar proliferation zone to 52.4%, 62.9%, 47.2%, and 54.0% of the controls, respectively. In contrast, we noted no reductions in the number of BrdU-labeled cells in the brains of the 15 dpf larvae. The double-label of BrdU and Hu, a neuronal marker, demonstrated that the majority of newborn cells showed the neuronal phenotype. Similarly, kainic acid (200 microM), a glutamatergic receptor agonist, significantly reduced the number of BrdU-labeled cells in the telencephalic area, diencephalic area, and medial tectal proliferation zone to 51.4%, 61.9%, and 40.4% of the controls, respectively. Physostigmine (500 microM), an acetylcholinesterase inhibitor, also reduced the number of BrdU-labeled cells in the telencephalic area, diencephalic area, medial tectal proliferation zone, and medial cerebellar proliferation zone to 52.8%, 35.9%, 30.5%, and 39.8% of the controls, respectively. All of these drugs resulted in electrographic seizures in the larval brain when perfused directly through artificial cerebrospinal fluid. These results indicated that seizures result in a massive reduction in cell proliferation in wide-ranging areas of the developing brain.
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Encéfalo , Proliferación Celular/efectos de los fármacos , Convulsivantes/farmacología , Neuronas/efectos de los fármacos , Potenciales de Acción/efectos de los fármacos , Animales , Encéfalo/citología , Encéfalo/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Bromodesoxiuridina/metabolismo , Relación Dosis-Respuesta a Droga , Proteínas ELAV/metabolismo , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Ácido Kaínico/farmacología , Larva , Pentilenotetrazol/farmacología , Fisostigmina/farmacología , Pez CebraRESUMEN
In this study, the effects of scopolamine, an acetylcholine muscarinic receptor antagonist, and physostigmine, an acetylcholinesterase inhibitor, on the learning ability and memory of zebrafish were evaluated using a passive avoidance response test. The zebrafish were trained to stay in a dark compartment to avoid a weight dropping into an acryl shuttle chamber with a central sliding door. The crossing time was increased significantly, from 30.7+/-40.8s to 179.3+/-27.3s in the training session and 179.9+/-28.0s in the test session carried out 2h later in the controls. When treatment with 200 microM scopolamine was administered for 1h prior to the training session, the crossing time did not increase. The scopolamine-induced learning deficit was ameliorated by pretreatment with 20 microM physostigmine for 1h prior to scopolamine treatment; the crossing time was similarly increased, as shown with the controls (60.9+/-11.5s, 130.9+/-27.5s, and 183.4+/-26.6s in the training session and 108.1+/-23.9s in the test session). When scopolamine treatment was administered after the training session, the crossing time in the test session was reduced significantly as compared to that noted in the third trial of the training session, which was also ameliorated by physostigmine pretreatment. These results show that scopolamine impairs both the acquisition of passive avoidance response and retention of the learned response, and that physostigmine rescues the amnesic effects of scopolamine in zebrafish.