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2.
Nurs Diagn ; 10(2): 57-64, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10633691

RESUMO

PURPOSE: To determine how many state nurse practice acts include the term or concept of "nursing diagnosis" and describe their similarities and differences. METHODS: Investigators independently divided the practice acts of the 50 states and the District of Columbia into those that did or did not include the term "nursing diagnosis" or the word "diagnosis" within a nursing context. To describe other differences, the investigators operationally defined and independently categorized each act as trendsetting, contemporary, or traditional. FINDINGS: Thirty-three of the 51 practice acts used the term "diagnosis" within nursing context. Of these 33, 13 were identified as trendsetters and 20 as contemporary. Seven trendsetting and 5 contemporary practice acts used the NANDA-based language or "response" when describing the "what" of nursing diagnosis. None of the trendsetting practice acts, but 8 of the contemporary acts, used the NANDA-based "individual, family or community" when describing the "who" of nursing diagnosis. CONCLUSIONS: The language of nursing is changing. The majority of practice acts now define the practice of professional nursing as including the diagnostic act, although the manner in which they use the term varies.


Assuntos
Descrição de Cargo , Licenciamento em Enfermagem/legislação & jurisprudência , Diagnóstico de Enfermagem/legislação & jurisprudência , Humanos , Autonomia Profissional , Terminologia como Assunto , Estados Unidos
3.
J Nurs Staff Dev ; 14(1): 17-22, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9661402

RESUMO

The authors present a practical, step-by-step process for developing, implementing, and evaluating self-directed learning modules for staff development and continuing education. The process is described in detail and includes specific examples for those who want to develop self-directed learning modules that are unique to a particular target population.


Assuntos
Educação Continuada em Enfermagem/organização & administração , Recursos Humanos de Enfermagem/educação , Desenvolvimento de Programas/métodos , Instruções Programadas como Assunto , Desenvolvimento de Pessoal/organização & administração , Humanos , Avaliação de Programas e Projetos de Saúde
4.
J Nurs Staff Dev ; 14(2): 73-80, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9592432

RESUMO

The impetus for cost containment may necessitate using teaching strategies different from traditional classroom models used in staff development. Educators can design self-directed learning modules to educate staff to work more effectively with special populations, such as children and elderly patients. Encompassing more than 40 years of literature, this review identifies the best modular designs, the cost benefits, and various studies about the effectiveness of self-directed learning modules.


Assuntos
Educação Continuada em Enfermagem/métodos , Instruções Programadas como Assunto , Desenvolvimento de Pessoal/métodos , Análise Custo-Benefício , Humanos , Instruções Programadas como Assunto/economia , Instruções Programadas como Assunto/normas , Psicologia Educacional
5.
FEMS Microbiol Lett ; 151(2): 225-30, 1997 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-9228757

RESUMO

Thymidylate synthase converts deoxyuridylate to deoxythymidylate. The thyA gene has been cloned and sequenced from Neisseria gonorrhoeae MS11. This gene has an open reading frame of 795-801 bp and encodes a product which shares 71% identity with its Escherichia coli homolog. Unlike its E. coli counterpart, gonococcal thyA has a large, upstream transcribed region (300+ bp) that lacks a translatable reading frame. Gonococcal thyA is capable of complementing an E. coli thyA null mutant and shares similar levels of sensitivity with trimethoprim.


Assuntos
Neisseria gonorrhoeae/enzimologia , Timidilato Sintase/análise , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Dados de Sequência Molecular , RNA Mensageiro/análise , Timidilato Sintase/química , Timidilato Sintase/genética , Trimetoprima/farmacologia
6.
Mol Microbiol ; 23(4): 649-56, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9157237

RESUMO

Integration host factor (IHF) is a small, heterodimeric DNA-binding protein with pleiotropic function. IHF was purified to apparent homogeneity from Neisseria gonorrhoeae. Gel-retardation assays demonstrated binding of IHF to the pilE promoter region. The IHF-binding site was identified by DNase I protection assays and mapped proximal to three previously defined pilE promoters. Removal of the putative IHF-binding domain from pilE promoter DNA negated retardation of the DNA fragment when assessed by gel-shift analysis. Kleinschmidt electron microscopy showed pronounced kinking of pilE promoter DNA following incubation with IHF. Isogenic N. gonorrhoeae strains were constructed that contained either a wild-type pilE locus or a deleted pilE locus where the IHF-binding domain was removed. Primer-extension analysis and Northern blotting of total gonococcal RNA showed that in the absence of IHF binding at the pilE promoter, transcription was reduced 10-fold. Together, these data indicate that IHF is a transcriptional co-activator of pilE.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Fímbrias , Glicoproteínas de Membrana/metabolismo , Neisseria gonorrhoeae/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Sequência de Bases , Sítios de Ligação/genética , Mapeamento Cromossômico , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , DNA Bacteriano/ultraestrutura , Proteínas de Ligação a DNA/isolamento & purificação , Genes Bacterianos , Fatores Hospedeiros de Integração , Glicoproteínas de Membrana/genética , Microscopia Eletrônica , Modelos Biológicos , Dados de Sequência Molecular , Neisseria gonorrhoeae/genética , Conformação de Ácido Nucleico , Regiões Promotoras Genéticas , Transcrição Gênica
7.
Mol Microbiol ; 23(1): 123-35, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9004226

RESUMO

The opa multigene family of Neisseria gonorrhoeae encodes 11 related outer-membrane proteins which phase vary in vitro and in vivo. Illegitimate recombination within direct pentameric DNA repeats, encoding the signal-peptide region of pre-Opas, leads to switches in expression states. Despite the conserved nature of the variation mechanism, specific genes are expressed at high frequencies in the transition from Opa- to Opa+. The genes which are expressed at elevated frequencies differ from the rest of the family with respect to promoter structure, based on sequence comparisons between the opa genes of strain MS11mk. We have analysed transcription of the opa gene family of N. gonorrhoeae MS11mk, focussing on the different promoters found among the 11 genes to determine whether increased levels of expression are associated with increased phase-variation rates. Primer extension and Northern blotting was used to assess the levels of transcription of three representative opa genes (opaA, B and C) in 'on' and 'off' states. Full-length opa mRNA was detected primarily in strains expressing the homologous gene. Truncated opa mRNA was constitutively expressed from all opa genes regardless of their expression state. Quantitative comparisons in N. gonorrhoeae were complicated by the simultaneous expression of all 11 genes and the cross-reactivity of mRNA probes. Expression levels from the individual promoters were therefore assessed by creating transcriptional and translational lacZ fusions to each of the representative opa promoters which lacked the DNA repeats responsible for variation. The expression levels were compared to the phase-variation rates of translational opa::phoA fusions containing the same promoters in addition to the corresponding coding repeat regions. A strong correlation was found between expression levels from the different promoters and the variation rates at which 'on' variants appeared from an 'off' population (i.e. opaA > opaB > opaC). These results provide an explanation for the favoured expression of specific Opa proteins and indicate that expression of opa genes may be regulated at the level of transcription.


Assuntos
Antígenos de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Neisseria gonorrhoeae/genética , Regiões Promotoras Genéticas , Proteínas da Membrana Bacteriana Externa/metabolismo , Clonagem Molecular , Escherichia coli/metabolismo , Variação Genética , Óperon Lac , RNA Bacteriano , RNA Mensageiro , Análise de Sequência de DNA
8.
Issues Ment Health Nurs ; 17(2): 153-68, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8707535

RESUMO

Myths and other issues surrounding menopause are examined on the basis of historical and current literature from medicine, psychiatry, and psychiatric nursing, and on current research. Changes in the psychiatric view of menopause and mental illness reflect a more holistic view of menopause. Some effects of menopause during this normal transitional phase of a woman's life are explored with respect to the developmental, physiological, and cognitive/psychosocial domains. Concepts of menopause as disease or as normal development are discussed as well as issues related to "care or cure" interventions for menopausal women. Evidence supports the need for systematic longitudinal research studies on the use of hormone therapies to provide information on their long-term effects on the menopausal woman. The use of hormone therapies alone or in conjunction with other holistic interventions is discussed. Nurses have a professional responsibility to come to terms with the continuing conflict related to hormone therapies so that they may provide appropriate nursing interventions to celebrate this passage rather than deny it.


Assuntos
Terapia de Reposição de Estrogênios , Saúde Holística , Menopausa , Saúde Mental , Saúde da Mulher , Atitude Frente a Saúde , Feminino , Humanos , Menopausa/efeitos dos fármacos , Menopausa/fisiologia , Menopausa/psicologia , Pessoa de Meia-Idade
9.
Mol Microbiol ; 18(3): 491-505, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8748033

RESUMO

The processing-defective outer membrane porin protein LamBA23D (Carlson and Silhavy, 1993) and a tripartite fusion protein, LamB-LacZ-PhoA (Snyder and Silhavy, 1995), are both secreted across the cytoplasmic membrane of Escherichia coli, where they exert an extracytoplasmic toxicity. Suppressors of these toxicities map to a previously characterized gene, cpxA, that encodes the sensor kinase protein of a two-component regulatory system. These activated cpxA alleles, designated as cpxA*, stimulate transcription of the periplasmic protease DegP (Danese et al., 1995), which in turn catalyses degradation of the tripartite fusion protein. In contrast, degradation of precursor LamBA23D is not significantly stimulated in a cpxA* suppressor background. In fact, increased levels of DegP in a wild-type background stabilized this protein. While a functional degP gene is required for full cpxA*-mediated suppression of both toxic envelope proteins, residual suppression is seen in cpxA* degP::Tn10 double mutants. Furthermore, cpxA* mutations suppress the toxicity conferred by the LamB-LacZ hybrid protein, which exerts its effects in the cytoplasm, sequestered from DegP. Together, these observations suggest that the activated Cpx pathway regulates additional downstream targets that contribute to suppression. A subset of these targets may constitute a regulon involved in relieving extracytoplasmic and/or secretion-related stress.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Escherichia coli , Escherichia coli/genética , Proteínas de Choque Térmico , Proteínas Periplásmicas , Proteínas Quinases , Sinais Direcionadores de Proteínas , Transdução de Sinais , Supressão Genética , Mapeamento Cromossômico , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Óperon Lac , Proteínas de Membrana/fisiologia , Mutação , Plasmídeos , Serina Endopeptidases/genética
11.
J Vet Diagn Invest ; 5(3): 317-21, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8396980

RESUMO

The susceptibility of swine to infection with encephalomyocarditis virus (EMCV) was assessed. Transmission of EMCV in a single exposure by gavage or intranasal routes was highly dose dependent. In a direct comparison, animals were exposed to EMCV by gavage, intranasal, intramuscular, intratracheal, or transdermal routes. A higher proportion of animals exposed by transdermal (5/5), intratracheal (5/5), or intramuscular (5/5) routes than those exposed by intranasal (2/5) or gavage (3/5) routes became infected. The large quantity of virus required to infect animals intranasally or orally suggests that transmission by these routes may not occur routinely in the field. Transmission of EMCV by wound contamination (transdermally) has not been reported previously. Although EMCV was recovered from rectal, external genitalia, and pharyngeal swabs, there was no evidence of pig-to-pig transmission of EMCV from experimentally infected animals to comingled sentinels.


Assuntos
Vírus da Encefalomiocardite , Infecções por Enterovirus/veterinária , Doenças dos Suínos/transmissão , Animais , Anticorpos Antivirais/sangue , Vírus da Encefalomiocardite/imunologia , Infecções por Enterovirus/patologia , Infecções por Enterovirus/transmissão , Feminino , Masculino , Suínos , Doenças dos Suínos/patologia
12.
J Bacteriol ; 175(11): 3327-34, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8501036

RESUMO

Proteins destined for either the periplasm or the outer membrane of Escherichia coli are translocated from the cytoplasm by a common mechanism. It is generally assumed that outer membrane proteins, such as LamB (maltoporin or lambda receptor), which are rich in beta-structure, contain additional targeting information that directs proper membrane insertion. During transit to the outer membrane, these proteins may pass, in soluble form, through the periplasm or remain membrane associated and reach their final destination via sites of inner membrane-outer membrane contact (zones of adhesion). We report lamB mutations that slow signal sequence cleavage, delay release of the protein from the inner membrane, and interfere with maltoporin biogenesis. This result is most easily explained by proposing a soluble, periplasmic LamB assembly intermediate. Additionally, we found that such lamB mutations confer several novel phenotypes consistent with an abortive attempt by the cell to target these tethered LamB molecules. These phenotypes may allow isolation of mutants in which the process of outer membrane protein targeting is altered.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Membrana Celular/metabolismo , Escherichia coli/metabolismo , Processamento de Proteína Pós-Traducional , Receptores Virais/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/biossíntese , Sequência de Bases , Transporte Biológico , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Genes Letais , Proteínas de Choque Térmico/biossíntese , Modelos Biológicos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fenótipo , Porinas , Sinais Direcionadores de Proteínas/metabolismo , Receptores Virais/genética , Recombinação Genética
13.
Synapse ; 11(3): 229-48, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1636152

RESUMO

The rates and patterns of discharge activity exhibited by 16 spontaneously active substantia nigra pars compacta dopamine neurons were studied in halothane-anesthetized rats using three types of quantitative measures: 1) mean discharge rates, 2) population characteristics of interspike interval samples, and 3) interspike interval time-series measures which were used to examine patterns in the ordering of interspike intervals. The mean discharge rate of these 16 cells was 2.9 +/- 0.3 spikes/sec, and each cell was classified as bursting (25% of the cells) or non-bursting (75%). The distribution of interspike intervals of non-bursting neurons were more normally distributed. Time-series analyses (raw time-series plots, return maps, and phase portraits) revealed a substantial oscillatory tendency in the magnitudes of consecutive interspike intervals in these neurons under baseline conditions: Successive interspike intervals tended to alternate between short and long durations, although short bursts often occurred. Under baseline conditions, these cells exhibited both multispike bursts and consecutive long intervals less frequently than would have been predicted by chance ordering of the interspike intervals. These results imply that there are mechanisms acting to reduce the probability of these types of events. Locally infused nicotine enhanced discharge rates in these neurons. Burst firing increased in four neurons, while five neurons did not show any change in burst firing. LY 163502 induced significant decreases in both discharge rate and bursting activity in all cells tested. The variation coefficient, skew, and kurtosis of the interspike interval distributions were not consistently altered by either drug. The local infusion of either nicotine or LY 163502 decreased the oscillatory phenomenon seen in the baseline condition. Neither the nicotine or LY 163502 time-series data exhibited a larger proportion of long-short and short-long pairs (relative to the median interval) than would be expected by chance. It is hypothesized that these neurons have intrinsic mechanisms, made manifest under anesthesia, which induce oscillations in interspike interval length. The oscillatory effect of these mechanisms can be overridden by tonic increases in either excitatory or inhibitory tone.


Assuntos
Neurônios/fisiologia , Nicotina/farmacologia , Quinolinas/farmacologia , Substância Negra/fisiologia , Anestesia , Animais , Dopamina/fisiologia , Eletrofisiologia , Potenciais Evocados/efeitos dos fármacos , Masculino , Neurônios/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Técnicas Estereotáxicas , Substância Negra/citologia , Substância Negra/efeitos dos fármacos , Fatores de Tempo
14.
J Vet Diagn Invest ; 4(2): 139-43, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1616978

RESUMO

Severe clinical signs of swine infertility and respiratory syndrome (SIRS) of unknown cause were observed in several Minnesota swine farms between November 1990 and March 1991. Forty-five lung samples of weak pigs were collected from 13 swine farms, and virus isolation was attempted using swine alveolar macrophage (SAM) cultures. A cytopathic virus was isolated from 19 lung samples collected from 6 different farms. Four pregnant sows were infected intranasally with a tissue suspension from which virus was isolated, and 4 6-week-old pigs and 2 contact pigs were infected intranasally with 1 of the isolates. The 4 sows farrowed 12 stillborn and 32 normal pigs. Virus was recovered from 10 of 19 pigs examined. Infected 6-week-old pigs were clinically normal except for slightly elevated rectal temperatures and mild respiratory signs. No or mild interstitial pneumonic lesions were observed in inoculated pigs, but the lesion was obvious in the 2 contact pigs. Seroconversion was observed in sows and pigs as measured by indirect fluorescent antibody (IFA). Serologic identification of the isolates was carried out by IFA using reference serum prepared from an experimentally infected sow. A cytoplasmic fluorescence was observed on the SAM monolayers infected with each of the 19 different isolates. Fluorescence was also observed when the monolayers were tested with SIRS virus ATCC VR-2332-infected sow sera. Replication of the isolates was not affected in the medium containing 5-iodo-2'-deoxyuridine but was inhibited by treatment with ether. The isolates were relatively stable at 56 C and did not agglutinate with various erythrocytes tested.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Infertilidade Feminina/veterinária , Vírus de RNA/isolamento & purificação , Infecções Respiratórias/veterinária , Doenças dos Suínos/microbiologia , Viroses/veterinária , Animais , Células Cultivadas , Efeito Citopatogênico Viral , Feminino , Morte Fetal/microbiologia , Morte Fetal/veterinária , Imunofluorescência , Infertilidade Feminina/microbiologia , Pulmão/microbiologia , Pulmão/patologia , Macrófagos Alveolares/microbiologia , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Complicações Infecciosas na Gravidez/veterinária , Vírus de RNA/fisiologia , Infecções Respiratórias/microbiologia , Suínos , Síndrome , Viroses/microbiologia
15.
Synapse ; 5(2): 83-93, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2309160

RESUMO

The effects of the selective D-1 dopamine agonist SKF 38393, the selective D-2 agonist quinpirole, and the nonselective D-1/D-2 agonist apomorphine on spontaneous activity of globus pallidus neurons were compared in normal control rats and rats with unilateral 6-hydroxydopamine induced lesions of the nigrostriatal pathway. In control, unlesioned rats, SKF 38393 (0.4 and 10 mg/kg, i.v.) caused no significant net change in the activity of globus pallidus neurons, although some individual cells showed significant increases or decreases in discharge rates following 10 mg/kg SKF 38393 administration. In animals with unilateral 6-hydroxydopamine induced lesions, SKF 38393 caused greater increases and decreases in the discharge rates of a larger percentage of pallidal cells recorded on the ipsilateral side than in control, unlesioned animals. These rate changes were effectively reversed by the D-1 antagonist SCH 23390, but not by the D-2 antagonist YM-09151-2. Quinpirole (0.3 mg/kg, i.v.) produced modest rate increases in control, unlesioned animals and significantly larger rate increases in nigrostriatal lesioned animals. YM-09151-2, but not SCH 23390, effectively reversed quinpirole's effects in the lesioned animals. As previously reported, the nonselective D-1/D-2 agonist apomorphine (0.3 mg/kg, i.v.) produced large increases in discharge rates of pallidal cells in control, unlesioned rats. In contrast, in nigrostriatal lesioned rats, the discharge rates of some ipsilateral pallidal neurons were markedly increased, others were decreased, and some were unaffected following apomorphine administration. The dopamine antagonist spiroperidol partially to fully reversed these rate changes. In summary, apomorphine's neurophysiological profile appears to be an exaggeration of the D-1 agonist profile in the globus pallidus of these lesioned animals. The degree of change observed after apomorphine administration is consistent with results from other studies that have indicated that a synergistic interaction between effects triggered by stimulation of the two receptor subtypes can occur in these animals, as in control, unlesioned animals. However, these results further show that in rats with unilateral nigrostriatal lesions, the denervated dopamine receptors or the processes they mediate are altered so that they no longer have the requirement seen in controls for concurrent stimulation of the complementary dopamine receptor subtype for expression of the selective agonist effects.


Assuntos
Corpo Estriado/fisiologia , Globo Pálido/fisiologia , Receptores Dopaminérgicos/fisiologia , Substância Negra/fisiologia , 2,3,4,5-Tetra-Hidro-7,8-Di-Hidroxi-1-Fenil-1H-3-Benzazepina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Apomorfina/farmacologia , Corpo Estriado/efeitos dos fármacos , Ergolinas/farmacologia , Globo Pálido/efeitos dos fármacos , Masculino , Quimpirol , Ratos , Ratos Endogâmicos , Receptores Dopaminérgicos/efeitos dos fármacos , Substância Negra/efeitos dos fármacos
16.
Eur J Pharmacol ; 152(3): 289-300, 1988 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-2906003

RESUMO

Extracellular single unit recording techniques were used to investigate dopamine agonist-induced changes in the tonic activity of globus pallidus neurons in normal control rats, and in rats in which dopamine levels were acutely reduced by alpha-methyl-para-tyrosine (AMPT) pretreatment. Systemic administration of the nonselective D-1/D-2 agonist apomorphine consistently induced large increases in the firing rates of globus pallidus neurons, as shown previously. The D-1 agonist SKF 38393 frequently induced no change in pallidal cell firing rates with doses up to 20 mg/kg; however, firing rates of 40% of the cells were stimulated by more than 20% of baseline and 14% were partially inhibited after 20 mg/kg SKF 38393. Following AMPT pretreatment, SKF 38393 induced only increases and no changes in activity; no decreases were observed. The D-2 agonist quinpirole typically increased pallidal neuron activity in a dose-dependent manner but was markedly less effective at stimulating pallidal neuron activity than apomorphine. In AMPT-treated rats, quinpirole's effects were significantly attenuated. Consistent with previous results, most cells showed large rate increases when SKF 38393 and quinpirole were coadministered to normal rats; these increases were similar in magnitude to those induced by apomorphine. In contrast to the observation that AMPT treatment altered the responses of globus pallidus neurons to individually administered quinpirole and SKF 38393, neither the increases in pallidal cell activity induced by apomorphine nor those induced by coadministration of SKF 38393 and quinpirole were significantly attenuated in AMPT-treated rats. The results support the idea that stimulation of both D-1 and D-2 receptors appears to be required to induce apomorphine-like changes in basal ganglia output. Moreover, the effects of individually administered D-1 and D-2 agonists observed in normal rats appear to depend upon the degree to which the complementary receptor subtype is stimulated by endogenous dopamine.


Assuntos
Dopaminérgicos/farmacologia , Gânglios Espinais/metabolismo , Neurônios/metabolismo , Receptores Dopaminérgicos/metabolismo , 2,3,4,5-Tetra-Hidro-7,8-Di-Hidroxi-1-Fenil-1H-3-Benzazepina , Animais , Apomorfina/farmacologia , Depressores do Apetite/farmacologia , Comportamento Animal/efeitos dos fármacos , Benzazepinas/farmacologia , Ergolinas/farmacologia , Globo Pálido/metabolismo , Masculino , Metiltirosinas/farmacologia , Oxirredução , Quimpirol , Ratos , Ratos Endogâmicos , alfa-Metiltirosina
18.
Science ; 236(4802): 719-22, 1987 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-2953072

RESUMO

D1 and D2 dopamine receptors exert synergistic effects on the firing rates of basal ganglia neurons and on the expression of stereotyped behavior in rats. Moreover, the ability of D2 agonists to induce changes in basal ganglia single unit activity and spontaneous motor activity is dependent upon the presence of endogenous dopamine to stimulate D1 receptors; in rats treated with alpha-methyl-rho-tyrosine to reduce endogenous dopamine levels, the neurophysiological and behavioral effects of the D2 agonist quinpirole are significantly attenuated, while the effects of nonselective agonists like apomorphine, which stimulate both D1 and D2 receptors, or combinations of a D2 agonist and a D1 agonist are not attenuated. Thus, the previously held view that D2 receptors alone are responsible for evoking the changes in behavior and basal ganglia output induced by nonselective dopamine agonists and endogenous dopamine is not supported by these results, which indicate that these phenomena require concurrent stimulation of both dopamine receptor subtypes.


Assuntos
Gânglios da Base/fisiologia , Receptores Dopaminérgicos/fisiologia , Comportamento Estereotipado/fisiologia , 2,3,4,5-Tetra-Hidro-7,8-Di-Hidroxi-1-Fenil-1H-3-Benzazepina , Animais , Apomorfina/farmacologia , Benzazepinas/farmacologia , Dopamina/fisiologia , Ergolinas/farmacologia , Metiltirosinas/farmacologia , Neurônios/fisiologia , Fenetilaminas/farmacologia , Quimpirol , Ratos , Receptores Dopaminérgicos/efeitos dos fármacos , Receptores de Dopamina D1 , Receptores de Dopamina D2 , alfa-Metiltirosina
20.
Brain Res ; 400(2): 205-18, 1987 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-2880637

RESUMO

The abilities of 4 dopamine agonists to inhibit the tonic single unit activity of substantia nigra dopamine neurons and stimulate tonic activity of globus pallidus neurons were compared to study the agonists' effects on pre- and postsynaptic dopamine receptors, respectively. The agonists studied were apomorphine and pergolide, which interact with both D1 and D2 receptors, and the selective D2 agonists quinpirole and RU 24926. Drugs were administered systemically. The 4 dopamine agonists were equipotent and equiefficacious at inhibiting the firing rates of dopamine neurons. In contrast, their effects on pallidal cells were not identical; apomorphine and pergolide induced significantly greater increases in pallidal cell activity than did quinpirole and RU 24926. In addition, pretreatment with a small dose of quinpirole did not attenuate the excitatory effect of apomorphine on globus pallidus cell activity, as low doses of apomorphine have previously been shown to do. Possible mechanisms underlying the differences in efficacy between the non-selective and D2 selective dopamine agonists in the globus pallidus were investigated. Coadministering quinpirole with apomorphine did not significantly attenuate the effect of apomorphine, suggesting that quinpirole is not a partial agonist at postsynaptic dopamine receptors. In addition, prazosin pretreatment did not attenuate the stimulatory effect of pergolide on firing rates of pallidal cells, indicating that the greater efficacy of the non-selective agonists was not due to concurrent stimulation of alpha 1 adrenergic receptors and dopamine receptors. However, the effect of quinpirole on pallidal cell activity was significantly potentiated by pretreatment with the D1 agonist RS-SKF 38393 but not its inactive enantiomer S-SKF 38393. These results suggest that concurrent D1 and D2 receptor stimulation may be necessary for the full expression of postsynaptic receptor-mediated effects of dopamine and dopamine agonists in the basal ganglia.


Assuntos
Dopamina/fisiologia , Globo Pálido/fisiologia , Receptores Dopaminérgicos/fisiologia , Substância Negra/fisiologia , Sinapses/fisiologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Globo Pálido/citologia , Masculino , Neurônios/fisiologia , Ratos , Ratos Endogâmicos , Receptores de Dopamina D1 , Receptores de Dopamina D2 , Estimulação Química , Substância Negra/citologia
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