RESUMEN
Background: The use of generative artificial intelligence (AI) applications such as ChatGPT is becoming increasingly popular. In Japan, consumers can purchase most over-the-counter (OTC) drugs without having to consult a pharmacist, so they may ask generative AI applications which OTC drugs they should purchase. This study aimed to systematically evaluate responses from ChatGPT to consumer inquiries about various OTC drugs. Methods: We selected 22 popular OTC drugs and 12 typical consumer characteristics, including physical and disease conditions and concomitant medications. We input a total of 264 questions (i. e., all combinations of drugs and characteristics) to ChatGPT in Japanese, asking whether it is safe for consumers with each characteristic to take these OTC drugs. We used the generic name for 10 of the 22 drugs and the brand name for the remaining 12. Responses were evaluated based on the following three criteria: 1) coherence between the question and response, 2) scientific correctness, and 3) appropriateness of the instructed actions. When we received a response that satisfied all three criteria, we input the exact same question on a different day to assess reproducibility. Results: The proportions of ChatGPT's answers that satisfied criteria 1, 2, and 3 were 79.5%, 54.5%, and 49.6%, respectively. However, the proportion of responses that satisfied all three criteria was only 20.8% (55/264); 61.8% (34/55) of these responses were reproduced when the same question was input again on a different day. Compared with questions using generic names, those using brand names resulted in lower coherence and scientific correctness. Among the 12 characteristics, the appropriateness of the instructed actions tended to be lower in responses to questions about driving and concomitant medications. Conclusions: Our study revealed that ChatGPT was less accurate in its responses and less consistent in its instructed actions compared with the package inserts. Our findings suggest that Japanese consumers should not consult ChatGPT regarding OTC medications, especially when using brand names.
Asunto(s)
Inteligencia Artificial , Farmacéuticos , Humanos , Reproducibilidad de los Resultados , Japón , Medicamentos sin PrescripciónRESUMEN
Adriamycin (ADM), an anthracycline anticancer agent, is selectively stored in the nuclei of a variety of proliferating cells, but the precise mechanism of specific nuclear transport of ADM is not well known. Recently, we demonstrated that ADM shows high binding affinity to the cytoplasmic proteasomes of L1210 mouse leukemia cells and that taken up ADM by the cells selectively binds to proteasomes. Nuclear targeting of proteasome in proliferating cells may be mediated by the nuclear localization signals that are found in several of the alpha-type subunits of the 20S proteasome. To confirm nuclear transport of the ADM-proteasome complex, we synthesized a photoactive ADM analogue, N-(p-azidohenzoyl)-ADM, and generated a photoaffinity-labeled proteasome complex. The 26S proteasome purified from the cytosol of L1210 cells had a high affinity to N-(p-azidobenzoyl)-ADM. SDS-PAGE analysis of the photoaffinity-labeled proteasome showed that low molecular weight bands (approximately 21-31 kDa) of 20S proteasome had the highest photoaffinity. The photoaffinity-labeled proteasome was distributed in the cytoplasm and nuclei of digitonin-permeabilized L1210 and B-16 mouse melanoma cells in the presence of the cytosolic fraction and ATP. The rate of nuclear translocation of the proteasome was low in the absence of ATP. These results suggest that the proteasome is a specific translocator of ADM from the cytoplasm to the nucleus and that 20S proteasome components are the dominant ADM-binding sites. The nuclear transport of ADM-proteasome complex is regulated by an ATP-dependent nuclear pore-mediated mechanism.
Asunto(s)
Antibióticos Antineoplásicos/metabolismo , Núcleo Celular/metabolismo , Cisteína Endopeptidasas/metabolismo , Doxorrubicina/metabolismo , Complejos Multienzimáticos/metabolismo , Transporte Activo de Núcleo Celular/fisiología , Adenosina Trifosfato/metabolismo , Marcadores de Afinidad/química , Animales , Antibióticos Antineoplásicos/química , Permeabilidad de la Membrana Celular/efectos de los fármacos , Cisteína Endopeptidasas/química , Cisteína Endopeptidasas/aislamiento & purificación , Digitonina/farmacología , Doxorrubicina/química , Electroforesis en Gel de Poliacrilamida , Leucemia L1210/metabolismo , Melanoma Experimental/metabolismo , Ratones , Microscopía Confocal , Complejos Multienzimáticos/química , Complejos Multienzimáticos/aislamiento & purificación , Complejo de la Endopetidasa ProteasomalRESUMEN
PURPOSE: This study was performed to clarify the intracellular specificity of the differential cytotoxic effects of Adriamycin (ADM) on neoplastic and normal cells. METHODS: The mouse lymphocytic leukemia cell line L1210 and pig kidney proximal tubular epithelial cell line LLC-PK1 were used as neoplastic and normal cells, respectively. These cells were treated with various concentrations of ADM for 24 h and toxicological parameters were determined. RESULTS: ADM (0.1-10 microM) significantly down-regulated cell growth rate and [3H]thymidine incorporation into DNA in the log phase, and at concentrations of more than 1 microM reduced the viability of both cell lines. Lipid peroxidation was increased at 1 microM ADM in L1210 cells and at 10 microM ADM in LLC-PK1 cells. The microsomal and nuclear fractions of both cell lines showed approximately the same level of ADM-induced superoxide anion (O2-) production, while the mitochondrial fraction of differentiated LLC-PK1 cells produced the highest levels of O2-. Differentiated LLC-PK1 cells showed the highest mitochondrial NADH-cytochrome c reductase activity. L1210 cells showed lower mitochondrial activities of enzymes involved in scavenging of reactive oxygen species, such as superoxide dismutase, glutathione peroxidase and catalase, than the other cells. CONCLUSIONS: These results suggest that ADM exerts cytostatic effects on neoplastic and normal undifferentiated cells through the inhibition of DNA synthesis by DNA intercalation, and cytotoxic effects on neoplastic cells through the accumulation of reactive oxygen species resulting from low scavenger enzyme activities. The cytotoxic effects on normal differentiated cells may be related to the high levels of production of reactive oxygen species due to high mitochondrial NADH-cytochrome c reductase activity.
Asunto(s)
Antibióticos Antineoplásicos/farmacología , Doxorrubicina/farmacología , Células LLC-PK1/efectos de los fármacos , Leucemia L1210/tratamiento farmacológico , Animales , Antibióticos Antineoplásicos/administración & dosificación , División Celular/efectos de los fármacos , Grupo Citocromo c/metabolismo , Regulación hacia Abajo , Doxorrubicina/administración & dosificación , Peroxidación de Lípido/efectos de los fármacos , Ratones , Microsomas/efectos de los fármacos , Microsomas/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , NAD/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Superóxidos/metabolismo , Porcinos , Factores de TiempoRESUMEN
Aminoglycoside antibiotics are generally accepted to accumulate in renal proximal tubule cells from the luminal surface and show toxic effects on the cells. The binding affinity and membrane permeability of aminoglycoside antibiotics are different at the brush border membrane (BBM) and the basolateral membrane (BLM) of proximal tubule cells. This study was performed, therefore, to investigate the differential effects of the aminoglycoside antibiotic gentamicin (GM) on cultured LLC-PK1 cells, a pig kidney proximal epithelial cell line, after addition to the BBM or the BLM side. LLC-PK1 cells were cultured on microporous membranes until forming confluent monolayers, and then GM was added to either the BBM or the BLM side. GM caused release of enzymes from the organelles, with a higher level of release observed following addition to the BBM side than that to the BLM side. Patterns of [3H]GM uptake by the cells differed in a manner dependent on whether it was added to the BBM or the BLM side. That is, the cellular uptake from the BBM side increased with incubation time, while that from the BLM side showed rapid saturation. These results suggested that aminoglycoside antibiotics show differential effects on cultured proximal epithelial cells and have differential patterns of cellular uptake when added to the BBM or the BLM side.
Asunto(s)
Antibacterianos/toxicidad , Gentamicinas/toxicidad , Riñón/efectos de los fármacos , Animales , Antibacterianos/farmacocinética , Membrana Basal/efectos de los fármacos , Membrana Basal/metabolismo , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Gentamicinas/farmacocinética , Riñón/metabolismo , Células LLC-PK1 , Lisosomas/metabolismo , Masculino , Microvellosidades/efectos de los fármacos , Microvellosidades/metabolismo , PorcinosRESUMEN
To clarify the mechanism of cephalosporin nephrotoxicity, the cytotoxic effects of cephaloridine (CER), a nephrotoxic cephalosporin antibiotic, on the pig kidney proximal tubular epithelial cell line (LLC-PK1) were studied in culture. CER increased the content of hydrogen peroxide and decreased the activity of catalase in the treated cells, followed by an increase in the content of lipid peroxide and decreases in both glutathione peroxidase activity and in the non-protein sulfhydryl content. The levels of NADPH-dependent hydrogen peroxide and superoxide anion production by microsomes prepared from LLC-PK1 cells, and by NADPH-cytochrome P-450 reductase purified from the rat renal cortex were significantly increased by paraquat. The production of these molecules was antagonized by p-chloromer-curibenzoate, an inhibitor of NADPH-cytochrome P-450 reductase. On the other hand, CER did not significantly affect the production of hydrogen peroxide or superoxide anions. These results suggested that the cytotoxic effect of CER on cultured LLC-PK1 cells was due to the increases in hydrogen peroxide and lipid peroxide levels and not microsomal oxygen radical production, and that the mechanism of this cytotoxicity is very different from that of paraquat which induces microsomal oxygen radical production.
Asunto(s)
Cefaloridina/toxicidad , Cefalosporinas/toxicidad , Riñón/efectos de los fármacos , Peroxidación de Lípido , Oxígeno/metabolismo , Animales , Catalasa/metabolismo , Radicales Libres , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Peróxido de Hidrógeno/metabolismo , Riñón/enzimología , Riñón/metabolismo , Corteza Renal/efectos de los fármacos , Corteza Renal/metabolismo , Células LLC-PK1 , Peróxidos Lipídicos/metabolismo , Masculino , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo , PorcinosRESUMEN
To clarify the mechanism of cephalosporin nephrotoxicity, the effects of cephaloridine (CLD), a nephrotoxic cephalosporin antibiotic, on the mitochondria of the pig kidney proximal tubular epithelial cell line LLC-PK(1) were studied in culture. The activity of cytochrome c oxidase in the mitochondria of LLC-PK(1) cells was significantly decreased from 9 h after addition of 1.0 mM CLD to the cultured cells. These effects were dose-dependent and accompanied with a significant decrease in the ATP content in the cells, followed by marked morphological changes in the mitochondria. These alterations were observed in the treated cells before the increase in lipid peroxidation. The activities of NADH-cytochrome c reductase and succinate dehydrogenase in the mitochondria and NADPH-cytochrome P450 reductase, NADH-cytochrome b(5) reductase, and 7-ethoxycoumarin O-deethylase in the microsomes of the treated cells were not affected. Superoxide anion production by the mitochondria prepared from LLC-PK(1) cells or NADH-cytochrome c reductase was not affected by addition of CLD (1-10 mM), but adriamycin (0.1 mM) or paraquat (0.1 mM) significantly increased the superoxide anion production. These results suggested that the primary action of CLD is inhibition of cytochrome c oxidase activity in the mitochondrial electron transport chain, which decreases intracellular ATP content in renal tubular epithelial cells and that these effects of CLD are followed by increased lipid peroxidation and cellular injury.
Asunto(s)
Cefaloridina/farmacología , Cefalosporinas/farmacología , Complejo IV de Transporte de Electrones/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Células Epiteliales/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Animales , Células Cultivadas , Doxorrubicina/farmacología , Células Epiteliales/citología , Células Epiteliales/ultraestructura , Enfermedades Renales/inducido químicamente , Enfermedades Renales/metabolismo , Túbulos Renales Proximales/citología , Túbulos Renales Proximales/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Microsomas/efectos de los fármacos , Microsomas/enzimología , Mitocondrias/diagnóstico por imagen , Mitocondrias/enzimología , Paraquat/farmacología , Porcinos , UltrasonografíaRESUMEN
An intracellular adriamycin (ADM)-binding protein purified from the cytosol of L1210 mouse lymphocytic leukemia cells had a molecular weight of 700-1500 kDa and hydrolyzed Suc-LLVY-MCA. When L1210 cells were incubated with a photoactive ADM analogue, N-(p-azidobenzoyl)-adriamycin (NAB-ADM), most of the NAB-ADM was found to localize in the nuclei. In situ photoaffinity labeling of L1210 cells with NAB-ADM resulted in low protease activity in the cytosol and nuclear extracts and the cells showed selective photoincorporation of NAB-ADM into the proteasome. These results suggest that the proteasome is a translocator of ADM from the cytoplasm to the nucleus and might therefore become a new candidate for cancer chemotherapy.
Asunto(s)
Cisteína Endopeptidasas/química , Doxorrubicina/análogos & derivados , Complejos Multienzimáticos/química , Animales , Cisteína Endopeptidasas/aislamiento & purificación , Doxorrubicina/química , Electroforesis en Gel de Poliacrilamida , Leucemia L1210/patología , Ratones , Complejos Multienzimáticos/aislamiento & purificación , Etiquetas de Fotoafinidad , Complejo de la Endopetidasa Proteasomal , Células Tumorales CultivadasRESUMEN
Influence of fluoride on exocrine pancreas cells was examined morphologically with traditional and prolonged osmium fixation techniques for electron microscopy in the enamel fluorosis model rats injected subcutaneously twice a day with 20 mg/kg body weight of sodium fluoride. Although the rough endoplasmic reticulum (rER) of exocrine pancreas cells in control rats was laminated and oriented parallel to the circumference of the nucleus, the rER of the cells in NaF-treated rats was dilated, disrupted the laminated arrangement, and changed to the globular-shape rER. Many intracisternal granules were formed in these globular-shape rER of the cells exposed to fluoride. Lots of autophagosomes were also seen in the exocrine cells with NaF treatment. The autophagosomes were limited with a double or multiple membranes, and contained cytoplasmic organelles and/or the intracisternal granules. The outer and inner leaflets of double membranes of the autophagosomes were usually separated by a distinct electron-lucent area. In prolonged osmium fixation, the area between the double membranes of the autophagosome was filled with osmiun reaction deposits. Many autophagosomes were encircled with the single or multiple osmiophilic layers. In some cases, the osmium positive saccules also surrounded the free surface of the globular-shape rER containing intracisternal granules. These findings indicate that fluoride disrupts the export of zymogens from the rER, resulting in formation of intracisternal granules and autophagosomes, and that the osmiophilic saccules participate in sequestration of cytoplasmic organelles in forming autophagosomes.
Asunto(s)
Retículo Endoplásmico Rugoso/efectos de los fármacos , Precursores Enzimáticos/metabolismo , Páncreas/efectos de los fármacos , Fluoruro de Sodio/toxicidad , Animales , Retículo Endoplásmico Rugoso/metabolismo , Masculino , Microscopía Electrónica , Páncreas/ultraestructura , Ratas , Ratas WistarRESUMEN
Changes in body temperature and cell infiltration, mediated by cytokines including tumor necrosis factor-alpha (TNF-alpha), occur during inflammation, but a role of body temperature on inflammatory responses remains obscure. Intraperitoneal injection of 10% casein to mice resulted in transient hypothermia followed by neutrophil accumulation in peritoneal cavities. Peritoneal TNF-alpha was rapidly raised, and pretreatment of mice with an anti-TNF-alpha antibody promoted temperature restoration and partially inhibited neutrophil accumulation. To investigate direct effects of body temperature on neutrophils, peritoneal or peripheral blood neutrophils were cultured at 35 degrees C or 37 degrees C with or without recombinant murine TNF-alpha (100 ng/ml) or a protein synthesis inhibitor cycloheximide (1 microg/ml). Significant inhibition of spontaneous and TNF-alpha-induced apoptosis was obtained at 35 degrees C compared with 37 degrees C, an effect that was not altered by the addition of cycloheximide. Moreover, phagocytic ability of peritoneal neutrophils was significantly enhanced by incubating them at the lower temperature. These results indicate that mild hypothermia induced by endogenous TNF-alpha has enhancing roles on neutrophil survival and function during peritoneal inflammation.
Asunto(s)
Apoptosis/fisiología , Hipotermia/inducido químicamente , Hipotermia/fisiopatología , Inflamación/fisiopatología , Neutrófilos/fisiología , Factor de Necrosis Tumoral alfa , Animales , Apoptosis/efectos de los fármacos , Temperatura Corporal/efectos de los fármacos , Caseínas/farmacología , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Cicloheximida/farmacología , Exudados y Transudados/citología , Exudados y Transudados/metabolismo , Inflamación/patología , Inyecciones Intraperitoneales , Ratones , Ratones Endogámicos ICR , Neutrófilos/efectos de los fármacos , Neutrófilos/patología , Peritoneo/metabolismo , Peritoneo/patología , Fagocitosis/fisiología , Inhibidores de la Síntesis de la Proteína/farmacología , Temperatura , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Peripheral innervation patterns of proprioceptive afferents from dorsal root ganglia and the mesencephalic trigeminal nucleus were assessed in trkC-deficient mice using immunohistochemistry for protein gene product 9.5 and parvalbumin. In trkC knockout mice, spinal proprioceptive afferents were completely absent in the limb skeletal muscles, M. biceps femoris and M. gastrocnemius, as previously reported. In these same animals, however, proprioceptive afferents from mesencephalic trigeminal nucleus innervated masseter muscles and formed primary endings of muscle spindles. Three wild-type mice averaged 35.7 spindle profiles (range: 31-41), six heterozygotes averaged 32.3 spindles (range: 27-41), and four homozygotes averaged 32.8 spindles (range: 26-42). Parvalbumin and Nissl staining of the brain stem showed approximately 50% surviving mesencephalic trigeminal sensory neurons in trkC-deficient mice. TrkC-/- mice (n = 5) had 309.4 +/- 15.9 mesencephalic trigeminal sensory cells versus 616.5 +/- 26.3 the sensory cells in trkC+/+ mice (n = 4). These data indicate that while mesencephalic trigeminal sensory neurons are significantly reduced in number by trkC deletion, they are not completely absent. Furthermore, unlike their spinal counterparts, trigeminal proprioceptive afferents survive and give rise to stretch receptor complexes in masseter muscles of trkC knockout mice. This indicates that spinal and mesencephalic trigeminal proprioceptive afferents have different neurotrophin-supporting system during survival and differentiation. It is likely that one or more other neurotrophin receptors expressed in mesencephalic trigeminal proprioceptive neurons of trkC knockout mice compensate for the lack of normal neurotrophin-3 signaling through trkC.
Asunto(s)
Músculo Masetero/inervación , Neuronas Aferentes/fisiología , Propiocepción/fisiología , Receptor trkC/deficiencia , Animales , Tronco Encefálico/metabolismo , Supervivencia Celular , Ganglios Espinales/fisiología , Miembro Posterior/inervación , Inmunohistoquímica , Maxilares/inervación , Mesencéfalo/fisiología , Ratones , Ratones Noqueados/genética , Husos Musculares/ultraestructura , Músculo Esquelético/inervación , Neuronas Aferentes/citología , Neuronas Aferentes/metabolismo , Parvalbúminas/metabolismo , Receptor trkC/genética , Tioléster Hidrolasas/metabolismo , Núcleos del Trigémino/fisiología , Ubiquitina TiolesterasaRESUMEN
To examine the effect of food restriction on immune functions in the tumor-bearing state, mice were divided into a control group (fed 5.0 g diet/d; 71 kJ/d) and a 60% food-restricted group (fed 3.0 g diet/d; 43 kJ/d) at 8-wk of age, and 4 wk later, L1210 tumor cells were inoculated intradermally. In the food-restricted mice, tumor growth was significantly suppressed, and mean survival time after the tumor inoculation was prolonged (P < 0.05). The plasma concentrations of two antitumor cytokines, interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), were greater in the food-restricted group before tumor inoculation (P < 0. 05). Furthermore, the food-restricted mice had significantly higher plasma levels of IFN-gamma and TNF-alpha after tumor inoculation, although the treatment significantly increased these cytokine levels in both groups. Splenic natural killer cell cytotoxicity was also higher in the tumor-bearing food-restricted mice than in controls (P < 0.05). Food-restricted mice have strong antitumor immunity, and as a result, tumor growth is suppressed and survival time is prolonged in these mice.
Asunto(s)
Privación de Alimentos , Leucemia L1210/inmunología , Análisis de Varianza , Animales , Interferón gamma/sangre , Células Asesinas Naturales/inmunología , Masculino , Ratones , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
When an effective concentration of doxorubicin (DXR) was added into L1210 of a mouse leukemia cell line, DXR was rapidly distributed much more in the nuclei than in the other organelle within a few minutes. A [14C]DXR-binding fraction was obtained from the cytosol prepared from L1210 cells. The fraction was adsorbed to hydroxylapatite matrix and eluted from the matrix by 50-150 mM potassium phosphate buffer. The fraction showed high DXR-binding and Suc-Leu-Leu-Val-Tyr-MCA-degrading activity. The binding of [14C]DXR was inhibited by unlabeled DXR. Gel chromatography of the fraction with Sephacryl S-300 separated two fractions of high molecular weight (Peak I, approx. 750 kDa) and low molecular weight (Peak II). Peak I showed proteolytic activity. [14C]DXR-binding Peak I had much higher affinity to DNA-cellulose than [14C]DXR-binding Peak II. [14C]DXR-Peak I complex also was retained into the nuclei isolated from L1210 cells, temperature-dependently. These results suggest that a specific carrier to translocate DXR from cytoplasm into nucleus exists in L1210 cell and the carrier is proteasome.
Asunto(s)
Antibióticos Antineoplásicos/metabolismo , Proteínas Portadoras/metabolismo , Núcleo Celular/metabolismo , Cisteína Endopeptidasas/metabolismo , Citoplasma/metabolismo , Doxorrubicina/metabolismo , Leucemia L1210/metabolismo , Complejos Multienzimáticos/metabolismo , Animales , Transporte Biológico , Fraccionamiento Celular , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Citosol/metabolismo , Ratones , Complejo de la Endopetidasa Proteasomal , Células Tumorales CultivadasRESUMEN
In enamel fluorosis model rats treated with sodium fluoride, secretory ameloblasts of incisor tooth germs exhibited disruption of intracellular trafficking. We examined whether heterotrimeric G proteins participated in the disruption of vesicular trafficking of the secretory ameloblast exposed to fluoride, using immunoblotting and pertussis toxin (IAP)-induced adenosyl diphosphate (ADP)-ribosylation for membrane fractions of the cell. Immunoblotting of crude membranes, post supernatants of the ameloblast, with anti-G(alpha i3/alpha o) and anti-G(alpha s) antibodies showed that Gi3 or Go proteins existed in the secretory ameloblast, but Gs protein did not. Immunoblotting of the subcellular membrane fractions indicated that the Gi3 or Go proteins were located in the Golgi membrane, but were not in the rough endoplasmic reticulum (rER) membrane. Autoradiograph of IAP-induced ADP-ribosylation, however, showed the existence of IAP-sensitive G proteins both in rER and Golgi membranes. Fluoride treatment decreased the G proteins bound to both membranes. These findings indicate that different G proteins, both of which are IAP-sensitive, are present in the rER and Golgi apparatus, and suggest that these G proteins participate in the disturbance of intracellular transport of the secretory ameloblast exposed to fluoride.
Asunto(s)
Ameloblastos/efectos de los fármacos , Fluorosis Dental , Proteínas de Unión al GTP/fisiología , Fluoruro de Sodio/toxicidad , Adenosina Difosfato Ribosa/análisis , Ameloblastos/metabolismo , Animales , Autorradiografía , Transporte Biológico , Biopolímeros , Immunoblotting , Masculino , Ratas , Ratas WistarRESUMEN
Fluoride, which is an environmental toxicant, is a potent inducer of mottled enamel in humans and rats. To define the influence of fluoride on the secretory pathway in enamel fluorosis, mottled enamel was induced in the incisor tooth germs of rats by subcutaneous injections of sodium fluoride for 4 days, and then morphological and cytochemical changes of the secretory ameloblast were examined in the tooth germs with HRP-labeled lectin (Con A, GS-I, SBA and PNA) and En3 antibody labeling amelogenins. The accumulation of small vesicles on the route of the secretory pathway between the rER and the Golgi apparatus, disorder of Golgi stacks, and formation of abnormal large granules in distal cytoplasm were seen in the secretory ameloblast. Lectin staining patterns of the secretory ameloblast indicated the disturbance of the vesicular transport between the rER and the Golgi apparatus, and disorganization of the Golgi stack. Immunolabeling of the cell showed disruption of the sorting and fusion process on the secretory pathway. These results suggest that the fluoride disturbs the intracellular transport in the synthesis-secretory pathway of the ameloblast, and that this effect of fluoride on the synthesis-secretory pathway participates in the formation of enamel fluorosis.
Asunto(s)
Ameloblastos/metabolismo , Incisivo/efectos de los fármacos , Fluoruro de Sodio/toxicidad , Germen Dentario/efectos de los fármacos , Ameloblastos/química , Ameloblastos/ultraestructura , Amelogenina , Animales , Peso Corporal/efectos de los fármacos , Proteínas del Esmalte Dental/análisis , Fluorosis Dental/fisiopatología , Aparato de Golgi/ultraestructura , Histocitoquímica , Incisivo/química , Lectinas/análisis , Masculino , Microscopía Electrónica , Microscopía Inmunoelectrónica , Ratas , Ratas Wistar , Germen Dentario/químicaRESUMEN
BACKGROUND: The problem of how the functional compartments of the Golgi apparatus organizes during cell differentiation to become a well-formed Golgi apparatus is as yet an unresolved issue. This study was designed to define the involvement of the trans-Golgi network (TGN) and the Golgi stack in organizing the Golgi apparatus. METHODS: The distribution of the TGN marker enzyme was examined in the ameloblast of developing rat molar tooth germs using cytochemistry with Co-enzyme A phosphatase (CoA Pase) and cytidine monophosphatase (CMPase). RESULTS: Typically formed Golgi apparatus was observed in the secretory ameloblast but not in the presecretory ameloblast. Organization of the Golgi apparatus through the presecretory ameloblast was noted. In the presecretory ameloblast, Golgi stacks of different sizes and clusters of small vesicles were located in the cytoplasm lateral to the nucleus. The saccules with enzymes marked for TGN were also observed in the cytoplasm lateral to the nucleus. These saccules were adjacent to the cluster of small vesicles and/or the Golgi stack. Upon cell differentiation, Golgi stacks were seen in line along the long axis of the cell, and the file of the stacks in the cytoplasm lateral to the nucleus was formed. The positive saccule was seen in a parallel line equal to the length of the Golgi stacks. CONCLUSIONS: In organizing the Golgi apparatus, the development process of the TGN and the Golgi stack appear to be different, and new Golgi stacks seem to be formed through the accumulation of small vesicles near the pre-existing TGN.
Asunto(s)
Ameloblastos/enzimología , Aparato de Golgi/enzimología , Aparato de Golgi/ultraestructura , Diente Molar/enzimología , Diente Molar/ultraestructura , Germen Dentario/enzimología , Germen Dentario/ultraestructura , Ameloblastos/citología , Amelogénesis/fisiología , Animales , Diferenciación Celular , Microscopía Electrónica , Nucleotidasas/metabolismo , Monoéster Fosfórico Hidrolasas/metabolismo , Ratas , Ratas WistarRESUMEN
Changes of lectin staining patterns in the Golgi stack during cell differentiation were examined in the ameloblasts of developing rat molar tooth germs, using HRP-labeled lectins: Canavalia ensiformis (Con A), Griffonia simplicifolia I (GS-I), Glycine max (SBA), Ulex europeus I (UEA-I), Triticum vulgaris (WGA), and Arachis hypogaea (PNA). The Golgi stacks of the inner enamel epithelial cells and the presecretory ameloblasts were stained with the lectins, although the staining strength and pattern varied among the stacks with each lectin. In some cases, the reaction products for the lectins were observed in most or all saccules of the Golgi stack. In the secretory ameloblasts, however, discrete staining patterns of the Golgi stack were found for each lectin. The reaction products deposited in definite saccules of the Golgi stack of the secretory ameloblast, especially for UEA-I and PNA which stained only the trans Golgi saccules of the stack. The reaction-positive saccules distributed more extensively in the Golgi stack of the inner enamel epithelial cell and the presecretory ameloblast than in the secretory ameloblast. These findings suggest that the Golgi stack is not fully compartmentalized in the inner enamel epithelial cell and the presecretory ameloblast. It is proposed that, in the differentiating ameloblast, various glycosyltransferases may coexist in most saccules of the Golgi stack.
Asunto(s)
Ameloblastos/ultraestructura , Aparato de Golgi/ultraestructura , Germen Dentario/ultraestructura , Animales , Diferenciación Celular , Histocitoquímica , Lectinas , Microscopía Electrónica , Diente Molar/citología , Diente Molar/crecimiento & desarrollo , Diente Molar/ultraestructura , Ratas , Ratas Wistar , Germen Dentario/citología , Germen Dentario/crecimiento & desarrolloRESUMEN
White cells were collected from the wash of rat pleural cavity after exsanguination. The incubation mixture of the pleural cells with 1 microM phorbol myristate acetate (PMA) was extracted with acidified ethanol and purified with a Sep-pak C18. The resultant fraction containing prostaglandins (PG) and thromboxane (TX) was allowed to react with 9-anthryldiazomethane (ADAM). After removing contaminants and degraded reagent by silica gel Sep-pak, samples were applied to reversed phase high performance liquid chromatography of octadecylsilyl silica gel and monitored by a fluorescent detector. ADAM derivatives of the authentic PGD2, PGE2, PGF2 alpha, 6-keto-PGF1 alpha, 6-keto-PGE1, TXB2, 15-keto-PGE2, 13,14-dihydro-15-keto-PGF2 alpha and 13,14-dihydro-15-keto-PGE2 showed linear regression lines of peak heights within a range of 0.5-25 ng. By using this method PGD2, 6-keto-PGF1 alpha and TXB2 were detected in the incubation mixture of the rat pleural cells with PMA. The result clarified the origin of these PGs and TX found in the exudate of rat pleurisy induced by PMA. ADAM method for HPLC with a help of clean-up by Sep-pak could be a useful tool for detection of a series of arachidonate metabolites in biological materials.
Asunto(s)
Forboles/farmacología , Prostaglandina-Endoperóxido Sintasas/metabolismo , Prostaglandinas/análisis , Acetato de Tetradecanoilforbol/farmacología , Animales , Antracenos , Cromatografía Líquida de Alta Presión/métodos , Colorantes Fluorescentes , Cinética , Leucocitos/metabolismo , Masculino , Pleura , Ratas , Ratas EndogámicasRESUMEN
Rat pleurisy was induced by intrapleural injection of phorbol myristate acetate (PMA), a known tumor promotor and a component of croton oil. Pleural fluids at 30 min and 1 hr after PMA-injection were collected and arachidonic acid metabolites in the fluids were measured by RIA or bioassay after fractionation through reversed phase HPLC using an ODS column. The major metabolites found in the pleural fluid were 6-keto-PGF1 alpha, TXB2 and PGD2, with a small amount of PGE2. Pretreatment with 10 mg/kg indomethacin suppressed the pleural fluid accumulation and also reduced the amount of the above metabolites to the basal levels. Treatment with OKY-046, a novel thromboxane synthetase inhibitor, reduced the level of TXB2 completely, but had no effect on those of 6-keto-PGF1 alpha and PGD2, and it had no effect on pleural fluid accumulation either. The results may indicate that PGI2 plays a role for the vascular permeability increase in the early phase of pleurisy.