RESUMO
BACKGROUND: Single applications of sustained-release local anaesthetics may provide prolonged pain relief without requiring indwelling catheters, but have not yet been investigated for epidural postoperative pain management. We synthesized injectable sustained-release lidocaine particles (SRLPs) from biodegradable polymers and examined their effect in a rat model of postoperative pain. METHODS: Two types of polylactic acid particles, SRLP-10 and SRLP-25, containing 10% or 25% lidocaine, respectively, were generated and the lidocaine release was evaluated in vitro for 14 days. The SRLPs were then injected epidurally in the male Sprague-Dawley rats immediately before they received a hindpaw incision (the postoperative pain model), and hindpaw hypersensitivity was evaluated with the von Frey test. Motor paralysis and coordination were also assessed using a paralysis score and rota-rod test. Neurotoxicity and inflammation of the spinal cord, cauda equina, and tissue surrounding the injection site were histologically evaluated. RESULTS: In vitro, SRLP-10 and SRLP-25 released lidocaine over 7 and 3 days, respectively. The in vivo injection of SRLP-10 (80 mg) produced anti-hypersensitivity with no evidence of motor paralysis for 7 days after the paw incision, and SRLP-25 (60 mg) inhibited postoperative hypersensitivity for 7 days. Temporary motor paralysis (15 min) was observed after the injection of SRLP-25 (even with 40 mg). Foreign body reactions were observed around the SRLP injection site at 1 and 4 weeks after injection. No histopathological changes were observed at 1 or 4 weeks. CONCLUSIONS: The epidural injection of SRLPs produced prolonged anti-hypersensitivity in a rat model of postoperative pain with no major complications.
Assuntos
Anestésicos Locais/farmacologia , Lidocaína/farmacologia , Dor Pós-Operatória/tratamento farmacológico , Análise de Variância , Animais , Preparações de Ação Retardada , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Injeções Epidurais , Masculino , Medição da Dor/métodos , Ratos , Ratos Sprague-Dawley , TempoRESUMO
Thymic size and density were studied in 23 untreated patients with Graves' disease and 38 control subjects using computed tomography. Both thymic size and density were higher in untreated patients with Graves' disease than in control subjects in the age-matched group. After treatment with antithyroid drugs, both thymic size and density were significantly reduced, with a concomitant decrease in thyrotropin receptor antibodies. PCR of human thymic cDNA using primers for human thyrotropin receptor amplified a fragment in a size expected for the receptor, and its nucleotide sequence was identical to human thyrotropin receptor cDNA in the thyroid. Northern blot analysis of human thymic poly(A)+ RNA demonstrated the presence of the full length form of thyrotropin receptor mRNA. Western blot analysis of human thymic membrane using anti-thyrotropin receptor peptide antibodies demonstrated a band of 100 kD that was also observed in the thyroid membrane. Immunohistochemistry of thymic tissue using mouse antihuman thyrotropin receptor monoclonal antibodies demonstrated the immunostaining of epithelial cells. These results indicate that thymic hyperplasia is apparently associated with Graves' disease and suggest that thymic thyrotropin receptor may act as an autoantigen that may be involved in the pathophysiology of development of Graves' disease.
Assuntos
Doença de Graves/diagnóstico por imagem , Doença de Graves/patologia , Timo/diagnóstico por imagem , Timo/patologia , Adulto , Fatores Etários , Northern Blotting , Western Blotting , DNA Complementar/genética , Doença de Graves/tratamento farmacológico , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Tamanho do Órgão , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Receptores da Tireotropina/genética , Receptores da Tireotropina/imunologia , Receptores da Tireotropina/metabolismo , Timo/efeitos dos fármacos , Tomografia Computadorizada por Raios XRESUMO
We established a monoclonal antibody to human astrocytes using a human glial cell-rich fraction as the immunogen. The antibody, named PRAS-4, specifically labeled populations of astrocytes in a fine granular manner immunohistochemically. In formalin-fixed, paraffin-embedded tissue sections, PRAS-4-positive astrocytes were extensively distributed in the gray matter of the central nervous system, namely the cerebral cortex, basal ganglia, diencephalon, midbrain, various nuclei of the brain stem, cerebellar cortex and nuclei, and spinal cord. In the white matter, a few positive astrocytes were located mostly in the perivascular area. The reaction was lost after protease digestion and it resisted periodic acid, suggesting that the epitope is of a protein. The molecular weight of the antigen was estimated as 62 kDa. Ultrastructurally, the immunoreaction was localized on the outer and inner membranes of astrocytic mitochondria, and unlabeled mitochondria coexisted in the same cells. Extra-mitochondrial regions were not stained. PRAS-4 preferentially labeled astrocytes of the protoplasmic type, and may be applicable to studies on the development, specific functions and neoplasms of astrocytes.
Assuntos
Anticorpos Monoclonais/isolamento & purificação , Astrócitos/química , Mitocôndrias/imunologia , Adulto , Idoso , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos , Astrócitos/imunologia , Astrócitos/ultraestrutura , Biomarcadores , Córtex Cerebral/citologia , Córtex Cerebral/imunologia , Cromatografia de Afinidade , Cromatografia em Gel , Citoplasma/imunologia , Feminino , Proteína Glial Fibrilar Ácida/análise , Humanos , Imunoglobulina M/imunologia , Cadeias kappa de Imunoglobulina/imunologia , Imuno-Histoquímica , Masculino , Microscopia Imunoeletrônica , Pessoa de Meia-Idade , Mitocôndrias/química , Mitocôndrias/ultraestrutura , Glândula Pineal/química , Glândula Pineal/imunologiaRESUMO
Oligodendrogliomas are characterized by frequent loss of heterozygosity (LOH) on chromosomes 1p and 19q, but additional genetic alterations are likely to be involved. In this study, we screened 28 oligodendrogliomas (WHO grade II) and 20 anaplastic oligodendrogliomas (WHO grade III) for alterations in the RB1/CDK4/p16INK4a/p15INK4b and TP53/p14ARF/MDM2 pathways. In oligodendrogliomas, hypermethylation of RB1 (1 case) and p14ARF (6 cases) were the only detectable genetic changes (7/28, 25%). In anaplastic oligodendrogliomas, the RB1/CDK4/p16INK4a/p15INK4b signaling pathway regulating the G1 -->3 S transition of the cell cycle was altered in 13/20 (65%) cases, by either RBI alteration, CDK4 amplification, or p16IN4a/p15INK4b homozygous deletion or promoter hypermethylation. Further, 50% (10/20) of anaplastic oligodendrogliomas showed alterations in the TP53 pathway through promoter hypermethylation or homozygous deletion of the p14ARF gene and, less frequently, through TP53 mutation or MDM2 amplification. Of 13 anaplastic astrocytomas with an altered RB1 pathway, 9 (69%) also showed a dysregulated TP53 pathway. Thus, simultaneous disruption of the RB1/CDK4/p16INK4a/p15INK4b and the TP53/p14ARF/MDM2 pathways occurs in 45% (9/20) of anaplastic oligodendrogliomas, suggesting that these phenomena contribute to their malignant phenotype.
Assuntos
Genes p53/fisiologia , Oligodendroglioma/genética , Proteína do Retinoblastoma/genética , Transdução de Sinais/genética , Deleção de Genes , Inativação Gênica , Homozigoto , Humanos , Oligodendroglioma/metabolismo , Oligodendroglioma/patologia , Proteína do Retinoblastoma/metabolismoRESUMO
Noradrenergic neurons in the locus ceruleus contain neuropeptide Y and galanin, which project to the hypothalamic region. We have investigated the regulatory mechanisms of these peptides on norepinephrine release in rat hypothalamic slices in vitro. Neuropeptide Y and galanin significantly inhibited the stimulation-evoked [3H]norepinephrine release in a dose-dependent manner (1 Hz: S2/S1 ratio (mean +/- SEM), control 0.947 +/- 0.040, n = 11, neuropeptide Y 1 x 10(-8) M 0.509 +/- 0.013, n = 8, p less than 0.01, neuropeptide Y 1 x 10(-7) M 0.283 +/- 0.021, n = 8, p less than 0.01; galanin 1 x 10(-7) M 0.448 +/- 0.026, n = 8, p less than 0.01, galanin 1 x 10(-6) M 0.261 +/- 0.023, n = 8, p less than 0.01). The inhibition of norepinephrine release by the alpha-2 agonist UK 14,304 was potentiated by neuropeptide Y and galanin. The blockade of the alpha 2-adrenergic receptors by RX 781094 diminished the inhibitory effects of neuropeptide Y and galanin on norepinephrine release. Pretreatment of hypothalamic slices with islet activating protein (a toxin that interferes with the coupling of inhibitory receptors to adenylate cyclase) attenuated the suppression of norepinephrine release by UK 14,304, neuropeptide Y, and galanin. These results support the idea that neuropeptide Y and galanin are involved in the regulation of central adrenergic transmission partially mediated by alpha 2-adrenergic receptors and islet-activating protein-sensitive guanosine triphosphate-binding proteins in rat hypothalamus.
Assuntos
Hipotálamo/metabolismo , Neuropeptídeo Y/farmacologia , Norepinefrina/metabolismo , Peptídeos/farmacologia , Toxina Adenilato Ciclase , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Tartarato de Brimonidina , Dioxanos/farmacologia , Estimulação Elétrica , Galanina , Idazoxano , Técnicas In Vitro , Masculino , Norepinefrina/antagonistas & inibidores , Toxina Pertussis , Quinoxalinas/farmacologia , Ratos , Ratos Endogâmicos , Fatores de Virulência de Bordetella/farmacologiaRESUMO
The effect of dopamine (DA) uptake inhibitors (methamphetamine, nomifensine, and phenylethylamine) on the release of endogenous DA from striatal slices of rats pretreated with methamphetamine (6 mg/kg/day for 9 days) was investigated. The exposure of methamphetamine-pretreated rat striatal slices to a low concentration (10(-7) M, 5 X 10(-7) M) of methamphetamine caused a greater increase in DA efflux than that of saline-treated rat striatal slices. The drug-treated rats displayed an enhanced stereotyped behavioral response to a small dose of methamphetamine (1 mg/kg). Removal of Ca2+ from the superfusion medium did not affect the difference in the rates of methamphetamine (10(-7) M) induced DA release between methamphetamine-treated and saline-treated rat striatal slices. Nomifensine- and phenylethylamine-induced DA release from striatal slices was also enhanced by repeated administration of methamphetamine. On the other hand, there was no difference in K+-induced DA release between the two groups. Moreover, repeated administration of methamphetamine caused a significant increase in 3H-dopamine uptake in rat striatal synaptosomes. These results suggest that the behavioral sensitization produced by the repeated administration of methamphetamine is accompanied by an enhancement in the release of DA induced by methamphetamine, nomifensine, and phenylethylamine in vitro and is also accompanied by increased DA uptake into striatal synaptosomes.
Assuntos
Corpo Estriado/efeitos dos fármacos , Dopamina/metabolismo , Metanfetamina/farmacologia , Animais , Corpo Estriado/metabolismo , Técnicas de Cultura , Masculino , Ratos , Ratos Endogâmicos , Receptores Dopaminérgicos/efeitos dos fármacos , Comportamento Estereotipado/efeitos dos fármacos , Sinaptossomos/efeitos dos fármacosRESUMO
D-Xylose absorption was studied in 12 patients with acquired immunodeficiency syndrome (AIDS) or advanced AIDS-related complex who had had diarrhea for more than 8 weeks, averaged an 11% (range, 3% to 21%) body weight loss during the previous 6 months, and had had negative stool examinations for enteric pathogens. Patients were evaluated by duodenal aspiration and biopsy and received both 25 gm oral and 10 gm intravenous doses of D-xylose. Kinetic analysis of D-xylose absorption was characterized by an absorption rate constant (ka) and a rate constant (ko) reflecting nonabsorptive loss. Extent of D-xylose absorption averaged 18.4% +/- 9.3% (+/- SD) in the 12 patients (normal greater than 60%). Percentage of weight loss during the previous 6 months was negatively correlated with ka (r = -0.69; p = 0.018) in the 11 patients in whom this parameter was reduced but was not correlated with either ko or extent of D-xylose absorption. In these patients with human immunodeficiency virus enteropathy, ka was reduced out of proportion to the minor histologic changes present in the duodenal biopsy specimens.
Assuntos
Síndrome da Imunodeficiência Adquirida/metabolismo , Enteropatias/metabolismo , Xilose/farmacocinética , Síndrome da Imunodeficiência Adquirida/complicações , Administração Oral , Adulto , Disponibilidade Biológica , Biópsia , Peso Corporal/fisiologia , Diarreia/metabolismo , Humanos , Injeções Intravenosas , Absorção Intestinal , Enteropatias/etiologia , Intestino Delgado/metabolismo , Intestino Delgado/patologia , Linfócitos/fisiologia , Pessoa de Meia-Idade , Plasmócitos/fisiologiaRESUMO
Three patients with granulomatous hepatitis due to cytomegalovirus are described. They are compared to the three previously described patients with this disease, and their clinical and serologic characteristics are discussed. Similarities and differences between infectious mononucleosis (Epstein-Barr virus) and cytomegalovirus infections are adduced. That cytomegalovirus may be a cause of granulomatous hepatitis in the adult is stressed.
Assuntos
Infecções por Citomegalovirus/patologia , Granuloma/patologia , Hepatite Viral Humana/patologia , Adulto , Anticorpos Antivirais/análise , Biópsia , Medula Óssea/patologia , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/imunologia , Feminino , Hepatite Viral Humana/diagnóstico , Hepatite Viral Humana/imunologia , Humanos , Fígado/patologia , Pessoa de Meia-IdadeRESUMO
The effects of cholinergic and anticholinergic drugs on spontaneous or haloperidol-induced release of dopamine (DA) were studied in vitro. The slices of striatum were placed in a chamber and continuously superfused with Krebs' solution, containing various concentrations of haloperidol, with or without atropine, d-tubocurarine (d-TC), tetrodotoxin (TTX), physostigmine or carbachol. Haloperidol, enhanced the release of endogenous DA from the slices of striatum at an EC50 value of 25.6 microM. The effect of haloperidol was significantly reduced by atropine (2.5 microM), while it was unaffected by d-TC (10 microM) and TTX (1 microM). In contrast, physostigmine (3.7 microM) significantly increased the haloperidol-induced efflux of DA from the slices of striatum. In addition, acetylcholine (ACh), in the presence of physostigmine or carbachol, enhanced the basal efflux of DA at EC50 values of 2.8 microM and 83 microM, respectively. The effect of ACh on the efflux of DA was antagonized by atropine. These data suggest that haloperidol-induced release of DA is, at least partially, mediated by the activation of muscarinic ACh receptors located in the striatum.
Assuntos
Corpo Estriado/metabolismo , Dopamina/metabolismo , Haloperidol/farmacologia , Sistema Nervoso Parassimpático/fisiologia , Acetilcolina/metabolismo , Animais , Atropina/metabolismo , Corpo Estriado/efeitos dos fármacos , Técnicas In Vitro , Masculino , Terminações Nervosas/efeitos dos fármacos , Terminações Nervosas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Fisostigmina/metabolismo , Ratos , Ratos Endogâmicos , Tetrodotoxina/farmacologiaRESUMO
Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are multi-functional peptides derived from the same precursor, proadrenomedullin. We have studied the regulatory mechanism of expression of these peptides during neuronal differentiation of rat pheochromocytoma PC12 cells by nerve growth factor (NGF). The cellular levels of the peptides increased slightly, and then progressively decreased below the control by NGF. Immunoreactive (ir)-AM in the medium was transiently increased by NGF. Cytochemical staining showed that ir-AM and ir-PAMP were abundantly present in cytoplasm in the undifferentiated cells, and were decreased during culture with NGF. There was no preferential localization of ir-AM or ir-PAMP in neurites in comparison with in cytoplasm in the differentiated cells. Northern blot analysis showed that mRNA encoding these peptides, as detected as a band of 1.6 kb, increased more than three-fold at 1 h after the addition of NGF and then progressively decreased to one fifth of the control during 72 h. Degradation rate of the mRNA was slowed by NGF even when mRNA level is decreased after 72 h of NGF treatment. The transcription rate of their gene increased transiently and then decreased by the long-term treatment with NGF. These results demonstrate that expression of AM and PAMP is regulated by NGF along with time-dependent differentiation: AM gene transcription is transiently activated by NGF, whereas it was suppressed during neuronal differentiation of the cells.
Assuntos
Fator de Crescimento Neural/farmacologia , Neurônios/efeitos dos fármacos , Peptídeos/metabolismo , Biossíntese de Proteínas , Precursores de Proteínas/biossíntese , Adrenomedulina , Animais , Northern Blotting , Diferenciação Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica , Neurônios/citologia , Neurônios/metabolismo , Células PC12 , Biossíntese Peptídica/efeitos dos fármacos , Fragmentos de Peptídeos/biossíntese , Fragmentos de Peptídeos/efeitos dos fármacos , Peptídeos/efeitos dos fármacos , Feocromocitoma/metabolismo , Precursores de Proteínas/efeitos dos fármacos , Proteínas/efeitos dos fármacos , RNA Mensageiro/análise , Radioimunoensaio , Ratos , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacosRESUMO
In cultured bovine adrenal chromaffin cells, NS-7 [4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride], a newly-synthesized neuroprotective drug, inhibited veratridine-induced (22)Na(+) influx via voltage-dependent Na(+) channels (IC(50)=11.4 microM). The inhibition by NS-7 occurred in the presence of ouabain, an inhibitor of Na(+),K(+) ATPase, but disappeared at higher concentration of veratridine, and upon the washout of NS-7. NS-7 attenuated veratridine-induced (45)Ca(2+) influx via voltage-dependent Ca(2+) channels (IC(50)=20.0 microM) and catecholamine secretion (IC(50)=25.8 microM). Chronic (>/=12 h) treatment of cells with NS-7 increased cell surface [(3)H]-STX binding by 86% (EC(50)=10.5 microM; t(1/2)=27 h), but did not alter the K(D) value; it was prevented by cycloheximide, an inhibitor of protein synthesis, or brefeldin A, an inhibitor of vesicular transport from the trans-Golgi network, but was not associated with increased levels of Na(+) channel alpha- and beta(1)-subunit mRNAs. In cells subjected to chronic NS-7 treatment, (22)Na(+) influx caused by veratridine (site 2 toxin), alpha-scorpion venom (site 3 toxin) or beta-scorpion venom (site 4 toxin) was suppressed even after the extensive washout of NS-7, and veratridine-induced (22)Na(+) influx remained depressed even at higher concentration of veratridine; however, either alpha- or beta-scorpion venom, or Ptychodiscus brevis toxin-3 (site 5 toxin) enhanced veratridine-induced (22)Na(+) influx as in nontreated cells. These results suggest that in the acute treatment, NS-7 binds to the site 2 and reversibly inhibits Na(+) channels, thereby reducing Ca(2+) channel gating and catecholamine secretion. Chronic treatment with NS-7 up-regulates cell surface Na(+) channels via translational and externalization events, but persistently inhibits Na(+) channel gating without impairing the cooperative interaction between the functional domains of Na(+) channels.
Assuntos
Células Cromafins/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Pirimidinas/farmacologia , Canais de Sódio/efeitos dos fármacos , Animais , Brefeldina A/farmacologia , Cálcio/metabolismo , Catecolaminas/metabolismo , Bovinos , Células Cultivadas , Cicloeximida/farmacologia , RNA Mensageiro/análise , Saxitoxina/metabolismo , Veratridina/farmacologiaRESUMO
1. Long-term (> or = 12 h) treatment of cultured bovine adrenal chromaffin cells with A23187 (a Ca(2+) ionophore) or thapsigargin (TG) [an inhibitor of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA)] caused a time- and concentration-dependent reduction of cell surface [(3)H]-saxitoxin (STX) binding capacity, but did not change the K:(D:) value. In A23187- or TG-treated cells, veratridine-induced (22)Na(+) influx was reduced (with no change in veratridine EC(50) value) while it was enhanced by alpha-scorpion venom, beta-scorpion venom, or Ptychodiscus brevis toxin-3, like in nontreated cells. 2. The A23187- or TG-induced decrease of [(3)H]-STX binding was diminished by BAPTA-AM. EGTA also inhibited the decreasing effect of A23187. A23187 caused a rapid, monophasic and persistent increase in intracellular concentration of Ca(2+) ([Ca(2+)](i)) to a greater extent than that observed with TG. 2,5-Di-(t-butyl)-1,4-benzohydroquinone (DBHQ) (an inhibitor of SERCA) produced only a rapid monophasic increase in [Ca(2+)](i), without any effect on [(3)H]-STX binding. 3. Reduction in [(3)H]-STX binding capacity induced by A23187 or TG was attenuated by Gö6976 (an inhibitor of conventional protein kinase C) or calpastatin peptide (an inhibitor of calpain). When the internalization rate of cell surface Na(+) channels was measured in the presence of brefeldin A (an inhibitor of vesicular exit from the trans-Golgi network), A23187 or TG accelerated the reduction of [(3)H]-STX binding capacity. 4. Six hours treatment with A23187 lowered Na(+) channel alpha- and beta(1)-subunit mRNA levels, whereas TG had no effect. 5. These results suggest that elevation of [Ca(2+)](i) caused by A23187, TG or DBHQ exerted differential effects on down-regulation of cell surface functional Na(+) channels and Na(+) channel subunit mRNA levels.
Assuntos
Cálcio/metabolismo , Oxocinas , Canais de Sódio/metabolismo , Animais , Ligação Competitiva/efeitos dos fármacos , Brefeldina A/farmacologia , Calcimicina/farmacologia , Cálcio/farmacologia , Proteínas de Ligação ao Cálcio/farmacologia , ATPases Transportadoras de Cálcio/antagonistas & inibidores , Calpaína/antagonistas & inibidores , Carbazóis/farmacologia , Bovinos , Células Cultivadas , Células Cromafins/efeitos dos fármacos , Células Cromafins/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Inibidores Enzimáticos/farmacologia , Hidroquinonas/farmacologia , Indóis/farmacologia , Ionóforos/farmacologia , Toxinas Marinhas/farmacologia , Subunidades Proteicas , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático , Saxitoxina/metabolismo , Venenos de Escorpião/farmacologia , Sódio/metabolismo , Canais de Sódio/efeitos dos fármacos , Canais de Sódio/genética , Tapsigargina/farmacologia , Fatores de Tempo , Trítio , Veratridina/farmacologiaRESUMO
In isolated rat uterine strips, adrenomedullin (AM) inhibited the spontaneous periodic contraction in a concentration-dependent manner (IC(50)=22.3+/-0.7 nM). The inhibitory effect of AM was prevented by either AM(22-52), a putative antagonist for AM receptors, or calcitonin gene-related peptide (CGRP)(8-37), a putative antagonist for CGRP receptors. AM also attenuated bradykinin (BK)-induced periodic uterine contraction, which was blocked by AM(22-52) or CGRP(8-37), whereas AM had no effect on the periodic contraction caused by oxytocin or prostaglandin F(2alpha) (PGF(2alpha)). RT-PCR analysis showed that mRNAs for calcitonin receptor-like receptor (CRLR), receptor-activity-modifying protein (RAMP)1, RAMP2 and RAMP3 were expressed in the rat uterus. These results demonstrate that AM selectively inhibits spontaneous and BK-induced periodic contraction via activating receptors for AM and CGRP.
Assuntos
Anti-Hipertensivos/farmacologia , Bradicinina/farmacologia , Contração Muscular/efeitos dos fármacos , Peptídeos/farmacologia , Útero/efeitos dos fármacos , Adrenomedulina , Animais , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Proteína Semelhante a Receptor de Calcitonina , Dinoprosta/farmacologia , Relação Dose-Resposta a Droga , Feminino , Técnicas In Vitro , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Membrana/genética , Ocitocina/farmacologia , Fragmentos de Peptídeos/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Proteína 2 Modificadora da Atividade de Receptores , Proteína 3 Modificadora da Atividade de Receptores , Proteínas Modificadoras da Atividade de Receptores , Receptores da Calcitonina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Útero/metabolismo , Útero/fisiologiaRESUMO
We studied whether a novel proadrenomedullin derived peptide was present and what was its physiological function in cultured bovine adrenal chromaffin cells. We found a high level of proadrenomedullin N-terminal 12 peptide (PAMP-12) which consists of a peptide from 9th amino acid to 20th amino acid of proadrenomedullin N-terminal 20 peptide (PAMP-20). PAMP-12 was released from the cells along with catecholamine upon stimulation of nicotinic cholinergic receptors. When PAMP-12 was added in the incubation medium, this peptide inhibited nicotinic receptor-mediated catecholamine release and influx of Na(+) and Ca(2+) into the cells. PAMP-12 did not affect catecholamine release evoked by histamine or by depolarization by high concentration of potassium. PAMP-12 also inhibited synthesis of catecholamines as well as the activation of tyrosine hydroxylase by nicotinic stimulation. Thus, PAMP-12 is an endogenous peptide that regulates release and synthesis of catecholamines by acting on nicotinic cholinergic receptors in an autocrine manner in adrenal chromaffin cells.
Assuntos
Células Cromafins/metabolismo , Fragmentos de Peptídeos/metabolismo , Peptídeos , Proteínas/metabolismo , Receptores Nicotínicos/metabolismo , Medula Suprarrenal/citologia , Medula Suprarrenal/metabolismo , Adrenomedulina , Animais , Anticorpos , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Carbacol/farmacologia , Radioisótopos de Carbono , Catecolaminas/metabolismo , Bovinos , Agonistas Colinérgicos/farmacologia , Células Cromafins/citologia , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/farmacologia , Proteínas/imunologia , Proteínas/farmacologia , Sódio/metabolismoRESUMO
The actions and the presence of adrenomedullin (AM) were investigated in cultured human oligodendroglial cell line KG1C. AM and AM mRNA were detected in KG1C cells by immunohistochemistry and RT-PCR. mRNAs for calcitonin receptor-like receptor (CRLR) and receptor-activity-modifying proteins (RAMPs) 1, 2 and 3 but not for calcitonin receptors were detected in the cells, while mRNAs for CRLR, calcitonin receptors and all RAMPs were detected in the human cerebellum. Application of AM resulted in time- and concentration-dependent increases in the cAMP level of KG1C cells. Calcitonin gene-related peptide (CGRP) and amylin, peptides structurally related to AM, also increased cAMP. The potencies for the cAMP production of the three peptides were CGRP > or =AM >> amylin with EC(50) of 8, 18, 90 nM, respectively. The responses induced by AM were strongly inhibited by the CGRP(1) receptor antagonist human CGRP(8-37), and inhibited also by the AM receptor antagonist human AM(22-52). In contrast, the responses induced by CGRP or amylin were inhibited only by CGRP(8-37) and not by AM(22-52). The responses induced by all three peptides were unaffected by the amylin receptor antagonist human amylin(8-37). The CGRP(2) receptor agonist human [Cys(Acm)(2,7)]CGRP significantly increased the cAMP level but the increase was smaller than that caused by CGRP. This increase in cAMP was unaffected by CGRP(8-37), AM(22-52) or by amylin(8-37). These results suggest that in KG1C cells, AM increases cAMP through AM and CGRP(1) receptors, whereas CGRP does so through CGRP(1) and CGRP(2) receptors, and amylin exerts its effects through CGRP(1) receptors. Collectively, these findings imply that AM released from oligodendroglial cells may play a role in the regulation of oligodendrocytes via autocrine/paracrine through AM receptors and CGRP(1) receptors.
Assuntos
Amiloide/fisiologia , Peptídeo Relacionado com Gene de Calcitonina/fisiologia , AMP Cíclico/biossíntese , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas do Tecido Nervoso/biossíntese , Oligodendroglia/metabolismo , Peptídeos/fisiologia , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Medula Suprarrenal/citologia , Adrenomedulina , Amiloide/farmacologia , Animais , Comunicação Autócrina , Neoplasias Encefálicas/patologia , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Proteína Semelhante a Receptor de Calcitonina , Bovinos , Células Cultivadas , Glioma/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Comunicação Parácrina , Fragmentos de Peptídeos/farmacologia , Peptídeos/antagonistas & inibidores , Peptídeos/farmacologia , Proteínas Modificadoras da Atividade de Receptores , Receptores da Calcitonina/biossíntese , Receptores da Calcitonina/genética , Receptores de Peptídeo Relacionado com o Gene de Calcitonina/efeitos dos fármacos , Receptores de Polipeptídeo Amiloide de Ilhotas Pancreáticas , Receptores de Peptídeos/antagonistas & inibidores , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
Six cases of primary lung cancer that closely mimic malignant pleural mesothelioma clinically and anatomically are compared with four proven cases of malignant pleural mesothelioma. Findings on roentgenograms of the chest, clinical history, and gross examination of the lung specimens are not helpful in distinguishing between these two neoplasms. Microscopic examination of the hematoxylin and eosin-stained tissues is often inconclusive. Tissues were stained with hematoxylin and eosin, PAS with and without diastase treatment (DPAS), mucicarmine, alcian blue, toluidine blue, and colloidal iron with and without digestion by testicular hyaluronidase. Among these histochemical methods, DPAS was found to be particularly useful in distinguishing the primary lung cancers from the mesotheliomas. All primary lung cancers except one showed DPAS-positive material (mucin) in both the cytoplasm of the cancer cells and within the lumina of neoplastic glands. In contrast, none of the mesotheliomas showed the presence of DPAS-positive material. Histologically, all lung cancers were glandular. Five were classified as bronchiolar carcinoma, the remaining one as poorly differentiated adenocarcinoma. In two of the bronchiolar carcinomas, a small subpleural primary focus was demonstrated. This finding suggests a possible origin of these cancers as a small subpleural tumor that became widely disseminated via the subpleural lymphatics. This form of primary lung cancer possesses sufficient gross and microscopic characteristics that recognition should be given to it as a variant of primary lung cancer, with emphasis on differentiating it from pleural mesothelioma.
Assuntos
Carcinoma/patologia , Neoplasias Pulmonares/patologia , Mesotelioma/patologia , Neoplasias Pleurais/patologia , Adenocarcinoma Bronquioloalveolar/patologia , Idoso , Carcinoma/diagnóstico , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Mesotelioma/diagnóstico , Pessoa de Meia-Idade , Neoplasias Pleurais/diagnósticoRESUMO
Vacuolization of duodenal enterocytes was found by light microscopic examination in five patients meeting the Centers for Disease Control criteria for the acquired immunodeficiency wasting syndrome. Four of these patients had chronic diarrhea and malabsorption as documented by an abnormal D-xylose test, whereas one patient had no diarrhea or malabsorption. Enterocyte vacuolization was patchy in distribution, although affected cells were most notable on villous tips. Staining with period acid-Schiff, acid-fast bacilli, periodic acid-Schiff following diastase treatment, Congo red, and alcian blue were negative, suggesting that vacuolization is due to lipid accumulation. Immunoperoxidase staining for the human immunodeficiency virus envelope protein gp41 was positive in lamina propria mononuclear cells in all five patients. The authors hypothesize that lipid accumulation represents an enterocyte response to injury, possibly by an indirect effect of the human immunodeficiency virus.
Assuntos
Caquexia/patologia , Duodeno/patologia , Infecções por HIV/patologia , Vacúolos/patologia , Adulto , Caquexia/etiologia , Infecções por HIV/complicações , Humanos , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
The significance of the human immunodeficiency virus (HIV) in the small intestinal lamina propria in patients with the acquired immune deficiency syndrome or conditions related to that syndrome who have chronic diarrhea and malabsorption is unclear. To investigate this issue, upper endoscopy (after a 12- to 16-hour fast) with duodenal biopsy and aspirate was performed in 20 HIV-infected seropositive homosexual men referred for diarrhea of more than 8 weeks duration (Group 2) and in 9 HIV-infected homosexual men referred for dysphagia or dyspepsia with no symptoms of malabsorption (Group 1). All biopsy specimens were examined by light microscopy and immunochemical staining with monoclonal antibody against HIV glycoprotein gp41. Electron microscopy was performed in 18 patients in Group 2 and in all patients in Group 1. Immunogold electron microscopy was used as a confirmatory test for identified HIV particles. In addition, D-xylose absorption was measured in all patients after a 25-g dose of D-xylose with measurement of serum D-xylose concentration 1 hour after the dose and measurement of 5-hour urinary D-xylose excretion. Mean serum D-xylose was 35.4 +/- 4.5 mg/dL in Group 1 and 15.8 +/- 2.3 mg/dL in Group 2 (P less than 0.001), whereas mean urine D-xylose was 5.5 +/- 0.6 g in Group 1 and 2.0 +/- 0.4 g in Group 2 (P less than 0.001). Immunoperoxidase for gp41 was positive in 5 (56%) patients in Group 1 and in 12 (60%) patients in Group 2. Lamina propria HIV viral particles were identified by electron microscopy in both patient groups. Viral particles were seen within and adjacent to the cytoplasm of mononuclear cells and were not present in enterocytes or neuroendocrine cells. There were no significant differences in serum or urine D-xylose tests between patients with and without lamina propria HIV. In addition, lipid accumulation in intercellular spaces near the basolateral membrane of adjacent enterocytes was seen in 33% of patients with chronic diarrhea. These findings suggest that lamina propria HIV is not a direct cause of enteropathy in HIV-infected patients and that lymphatic obstruction may be one pathophysiologic mechanism producing this malabsorptive state.
Assuntos
Duodenopatias/patologia , Infecções por HIV/complicações , Síndromes de Malabsorção/patologia , Biópsia , Doença Crônica , Diarreia/etiologia , Diarreia/patologia , Duodenopatias/microbiologia , Proteína gp41 do Envelope de HIV/análise , Infecções por HIV/metabolismo , Infecções por HIV/patologia , Humanos , Síndromes de Malabsorção/etiologia , Masculino , Microscopia EletrônicaRESUMO
The clinical application of a dopamine radioreceptor assay for neuroleptics has been proposed. Simultaneous monitoring of serum antidopaminergic (anti-DA), antiserotonergic (anti-5HT) antiadrenergic (anti-NA) activities may provide a better understanding of clinical effects of neuroleptics. Serum anti-DA and anti-5HT activities were estimated by competition for 3H-spiperone binding to dopamine and serotonin receptors in rat brain, respectively, and anti-NA activity by competition for 3H-WB-4101 binding to alpha-receptors. Thirty-one patients receiving maintenance doses of chlorpromazine (CPZ) chronically were studied. Serum activities varied among patients receiving the same dose, but correlated significantly with dose. Anti-DA activity also correlated with both anti-5HT anti-NA activities, and the average ratio of anti-5HT or anti-NA to anti-DA activity was slightly reduced by metabolism of CPZ. However, some patients had a different spectrum of serum activities from that of in vitro activities. Serum prolactin (PRL) correlated weakly with all the serum activities. The serum PRL anti-DA activity ratio appeared to be independent of anti-5HT or anti-NA activity, suggesting the predominant involvement of anti-DA activity in the stimulation of PRL release.
Assuntos
Antagonistas Adrenérgicos alfa , Clorpromazina/uso terapêutico , Prolactina/sangue , Receptores Dopaminérgicos/efeitos dos fármacos , Receptores de Serotonina/efeitos dos fármacos , Esquizofrenia/sangue , Adulto , Idoso , Clorpromazina/sangue , Doença Crônica , Humanos , Masculino , Pessoa de Meia-Idade , Ensaio Radioligante , Esquizofrenia/tratamento farmacológicoRESUMO
AMPA type-glutamate receptor channels (AMPARs) assembled without the GluR2 (GluR-B) subunit are characterized by high Ca2+ permeability, and are expressed abundantly in cerebellar Bergmann glial cells. Here we show that the morphology of cultured Bergmann glia-like fusiform cells derived from the rat cerebellum was changed by manipulating expression of Ca2+-permeable AMPARs using adenoviral vector-mediated gene transfer. Converting endogenous Ca2+-permeable AMPARs into Ca2+-impermeable channels by viral-mediated transfer of GluR2 gene induced retraction of glial processes. In contrast, overexpression of Ca2+-permeable AMPARs markedly elongated glial processes. The process extension was blocked by 2,3-Dihydroxy-6-nitro-7-sulfamoylbenzo(F)quinoxaline (NBQX), a specific antagonist of AMPAR. These results indicate that glutamate regulates the morphology of glial processes by activating Ca2+-permeable AMPARs.