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2.
Clin Exp Rheumatol ; 26(1): 73-80, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18328150

RESUMO

OBJECTIVE: The aim of this study was to evaluate the effects of anti-TNF-alpha antibody, infliximab, on oxidative stress markers representing DNA damage, lipid peroxidation, and glycoxidation. METHODS: Twenty-three RA patients underwent infliximab treatment and were analyzed for 30 weeks. Six patients who experienced side effects and one patient who had a reduced efficacy of infliximab were discontinued the infliximab treatment at 30-54 weeks. Sixteen patients were analyzed for 54 weeks. The levels of serum total, urinary total, and free pentosidine, which is an advanced glycation end-product (AGE), and of urinary 15-Isoprostane F2t and 8-hydroxy-deoxy guanosine (8-OHdG) were determined at baseline and at 14, 30, and 54 weeks after initial treatment with infliximab. RESULTS: Serum total, urinary total, and free pentosidine levels were reduced at 54 weeks after initial infliximab treatment. Urinary 15-Isoprostane F2t and 8-OHdG levels were also reduced at 14, 30, and 54 weeks. Urinary 8-OHdG levels in RA patients correlated with CRP and the Disease Activity Score of 28 joints. CONCLUSION: In RA patients, infliximab plays an essential role as an anti-oxidative agent against AGE formation, oxidative DNA damage and lipid peroxydation.


Assuntos
Anticorpos Monoclonais/farmacologia , Antirreumáticos/farmacologia , Arginina/análogos & derivados , Artrite Reumatoide/tratamento farmacológico , Desoxiguanosina/análogos & derivados , Isoprostanos/urina , Lisina/análogos & derivados , 8-Hidroxi-2'-Desoxiguanosina , Anticorpos Monoclonais/uso terapêutico , Antirreumáticos/uso terapêutico , Arginina/análise , Arginina/sangue , Arginina/urina , Artrite Reumatoide/metabolismo , Dano ao DNA/efeitos dos fármacos , Desoxiguanosina/urina , Feminino , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Infliximab , Peroxidação de Lipídeos , Lisina/análise , Lisina/sangue , Lisina/urina , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Espécies Reativas de Oxigênio
3.
Trends Genet ; 15(11): 454-8, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10529808

RESUMO

Dosage compensation is a striking example of the interplay between gene-specific regulation and chromosomal architecture. This process has evolved to make X-linked gene expression equivalent in males with one X chromosome and females with two. Examining species at the molecular level has shown that dosage compensation is mediated by sex-specific factors that decorate the X chromosomes to regulate chromatin structure and gene expression. In Drosophila, dosage compensation is achieved, at least in part, through site-specific histone H4 acetylation, which is modulated by a male- and X-specific protein complex. The discovery of non-coding RNAs that 'paint' dosage-compensated X chromosomes in mammals and in Drosophila suggests that RNAs play an intriguing, unexpected role in the regulation of chromatin structure and gene expression.


Assuntos
Proteínas Cromossômicas não Histona/fisiologia , Mecanismo Genético de Compensação de Dose , Drosophila melanogaster/genética , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/fisiologia , Cromossomo X/genética , Animais , Cromatina/genética , Cromatina/ultraestrutura , Proteínas Cromossômicas não Histona/genética , Feminino , Hibridização in Situ Fluorescente , Proteínas de Insetos/genética , Masculino , Modelos Genéticos
4.
Mol Cell Biol ; 16(11): 6509-15, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8887679

RESUMO

The transcription factor FTZ-F1 is a member of the nuclear hormone receptor superfamily and is transiently expressed during the mid- and late prepupal periods in Drosophila melanogaster. A putative pupal cuticle gene, EDG84A, is expressed slightly following FTZ-F1 expression during the prepupal period and carries a strong FTZ-F1 binding site between bases 100 and 92 upstream of its transcription start site. In this study, EDG84A mRNA was found to be prematurely expressed upon heat induction of FTZ-F1 in prepupae carrying the heat shock promoter-FTZ-F1 cDNA fusion gene construct. Transgenic fly lines having the 0.8-kb region of the EDG84A promoter fused to lacZ expressed the reporter gene in a tissue- and stage-specific manner. Base substitutions in the FTZ-F1 binding site within the 0.8-kb promoter abolished expression of lacZ. These results strongly suggest that the EDG84A gene is a direct target of FTZ-F1. Deletion studies of the cis-regulatory region of the EDG84A gene revealed that space-specific expression in imaginal disc-derived epidermis is controlled by the region between bp -408 and -104 from the transcription start site. The region between bp -408 and -194 is necessary to repress expression in a posterior part of the body, while the region between bp -193 and -104 carries a positive element for activation in an anterior part of the body. These results suggest that FTZ-F1 governs expression of the EDG84A gene in conjunction with putative tissue-specific regulators.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Drosophila melanogaster/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos , Metamorfose Biológica , Biossíntese de Proteínas , Fatores de Transcrição/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Sequência Consenso , Proteínas de Ligação a DNA/biossíntese , Proteínas de Drosophila , Fatores de Transcrição Fushi Tarazu , Genes de Insetos , Genes Reporter , Proteínas de Homeodomínio , Especificidade de Órgãos , Regiões Promotoras Genéticas , Pupa , Receptores Citoplasmáticos e Nucleares , Proteínas Recombinantes/biossíntese , Sequências Reguladoras de Ácido Nucleico , Fator Esteroidogênico 1 , Fatores de Transcrição/biossíntese , Transcrição Gênica , Dedos de Zinco , beta-Galactosidase/biossíntese
5.
Mol Cell Biol ; 18(3): 1172-80, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9488432

RESUMO

Abnormal erythropoietin (EPO)-independent cell growth is induced after infection of erythroid progenitor cells with a polycythemic strain of Friend virus (FVp). Binding of its Env-related glycoprotein (gp55) to the EPO receptor (EPOR) mimics the activation of the EPOR with EPO. We investigated the gp55-EPOR signaling in erythroblastoid cells from mice infected with FVp and in cells of FVp-induced or gp55-transgenic-mouse-derived erythroleukemia cell lines, comparing it with the EPO-EPOR signaling in EPO-responsive erythroblastoid cells. While the Janus protein tyrosine kinase JAK2 and the transcription factor STAT5 became tyrosine phosphorylated with the EPO stimulation in EPO-responsive erythroblastoid cells from anemic mice, JAK1 and STAT5 were constitutively tyrosine phosphorylated in all of these FVp gp55-induced erythroblastoid or erythroleukemic cells. Moreover, this constitutively tyrosine-phosphorylated STAT5 was unable to bind to its specific DNA sequences and did not translocate to the nucleus. Nuclear translocation and DNA binding of this STAT5 species required EPO stimulation. These findings clearly indicate that the FVp gp55-EPOR signaling is distinct from the EPO-EPOR signaling and suggest that STAT5 may not play an essential role in the transmission of the cell growth signals in FVp gp55-induced erythroleukemia cells.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Células Precursoras Eritroides/metabolismo , Eritropoetina/metabolismo , Proteínas do Leite , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas , Receptores da Eritropoetina/metabolismo , Vírus Formadores de Foco no Baço/metabolismo , Transativadores/metabolismo , Proteínas do Envelope Viral/metabolismo , Animais , Núcleo Celular/metabolismo , Células Cultivadas , DNA/metabolismo , Ativação Enzimática , Células Precursoras Eritroides/citologia , Eritropoetina/farmacologia , Feminino , Humanos , Janus Quinase 1 , Janus Quinase 2 , Camundongos , Camundongos Endogâmicos DBA , Fosforilação , Receptores da Eritropoetina/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Fator de Transcrição STAT5 , Vírus Formadores de Foco no Baço/genética , Células Tumorais Cultivadas , Tirosina/metabolismo , Proteínas do Envelope Viral/genética
6.
Biochim Biophys Acta ; 1246(2): 189-96, 1995 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-7819287

RESUMO

Phospholipid-protein interactions have been investigated in a phospholipid-requiring enzyme, FAD-dependent malate dehydrogenase isolated from Mycobacterium smegmatis membranes, to correlate these interactions with enzyme function. The ability of several natural and synthetic phospholipids including CL and PE, which are major phospholipids in M. smegmatis membranes, to activate purified, lipid-depleted, enzymatically inactive malate dehydrogenase was examined. Anionic phospholipids and PE activated the enzyme, while zwitterionic phospholipids did not. A PE/PC mixture activated the enzyme in the form of both bilayer and non-bilayer structure. CL/PE mixtures activated malate dehydrogenase much more than each single phospholipid species. All anionic phospholipids used stabilized the enzyme, while PE and zwitterionic phospholipids did not. CL and a CL/PE mixture protected malate dehydrogenase from proteinase digestion, while PE did not. All phospholipids and phospholipid mixtures tested caused little secondary structural change in malate dehydrogenase. The results obtained in this study suggest that CL and CL/PE mixtures could form stable, enzymatically active complexes with malate dehydrogenase which might be similar to the native complex in M. smegmatis membranes. Although PE could activate malate dehydrogenase in both bilayer and non-bilayer form, it formed a complex with malate dehydrogenase which was inferior in terms of stability and susceptibility to proteinases, indicating that PE alone poorly reconstitutes the active enzyme-phospholipid complex.


Assuntos
Malato Desidrogenase/metabolismo , Mycobacterium/enzimologia , Fosfatidiletanolaminas/farmacologia , Fosfolipídeos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Estabilidade Enzimática/efeitos dos fármacos
7.
Biochim Biophys Acta ; 1243(3): 300-8, 1995 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-7727503

RESUMO

This study has aimed at taking information necessary for design of anticancer prodrugs modified with chiral acyl group, especially about the effect of chirality of the acyl group on its enzymic removal in specific cells. Thus, 13 species of chiral esters were synthesized and stereoselectivity in their enzymic hydrolysis was investigated with six cancer cell lines, solid tumors, and the corresponding normal tissues. Cultured cancer cells from rat liver, pancreas, and muscle hydrolyzed the R enantiomer of (+/-)-ethyl 2-methoxy-2-phenylacetate (3c) more preferentially than its antipode, whereas this stereoselectivity was reversed in the reaction by homogenate of the corresponding normal tissue of rat. The difference in stereoselectivity between cancer cells and normal tissue was also found in the hydrolysis of other esters including those of actual anticancer agents, p-hydroxyaniline mustard and 5-fluorouridine. The investigation was expanded to real tumor to show that the degree of stereoselectivity or the hydrolytic activity was significantly different between a human brain tumor and its surrounding normal tissue for such substrates as (+/-)-ethyl 2-phenoxypropanoate and N-trifluoroacetylphenylalaninate. The esterases of rat liver cancer cells (Anr4) and normal rat liver gave different band patterns in active staining after gel electrophoresis. The enzymes were fractionated by ion exchange column chromatography and then tested on their stereoselectivity against (+/-)-3c. Comparison of the results and electrophoretograms of the fractions suggests that esterases with different stereoselectivity are expressed in different ways by normal and cancer cells. These results show that stereoselectivity in enzymic hydrolysis of some synthetic chiral esters is different between cancer and normal cells, leading to the possibility that specific activation of ester-type anticancer prodrugs in cancer cells would be controlled by the chiral structure of the acyl group.


Assuntos
Ésteres/metabolismo , Neoplasias/metabolismo , Animais , Antineoplásicos/metabolismo , Neoplasias Encefálicas/metabolismo , Ésteres/química , Humanos , Hidrólise , Fígado/metabolismo , Neoplasias Hepáticas/metabolismo , Masculino , Músculos/metabolismo , Pâncreas/metabolismo , Neoplasias Pancreáticas/metabolismo , Fenilacetatos/química , Fenilacetatos/metabolismo , Ratos , Ratos Wistar , Estereoisomerismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
8.
Biochim Biophys Acta ; 1399(1): 62-6, 1998 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-9714739

RESUMO

The cDNA for the seventh mammalian aquaporin (AQP7) was isolated from rat testis, and its expression demonstrated at the tail of late spermatids (Ishibashi et al., J. Biol. Chem. 272 (1997) 20,782-20,786). Here we report the isolation of the mouse and the human AQP7 cDNA and the human AQP7 gene. The human AQP7 gene is identical with human adipose AQP (AQPap or AQP7L). The deduced amino acid sequences of human and mouse AQP7 were 68% and 79% identical to those of rat AQP7, respectively. The mouse AQP7 is 67% identical to the human AQP7. Such a lower conservation of AQP7 among species is unusual in the aquaporin family. The human AQP7 gene is composed of six exons distributing over 6.5 kb. The exon-intron boundaries are identical to those of the human AQP3 gene. The intron sizes are also similar. Moreover, chromosomal localization of AQP7 was assigned to 9p13 by fluorescent in situ hybridization, where AQP3 is also localized, suggesting that 9p13 may be another site of an aquaporin cluster.


Assuntos
Aquaporinas , Canais Iônicos/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Mapeamento Cromossômico , Clonagem Molecular , DNA Complementar/química , DNA Complementar/isolamento & purificação , Humanos , Canais Iônicos/química , Masculino , Camundongos , Dados de Sequência Molecular , Alinhamento de Sequência , Testículo/metabolismo
9.
Endocrinology ; 125(4): 2227-9, 1989 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2791989

RESUMO

This study examined the effects of calcitonin gene-related peptide (CGRP) on aldosterone secretion both in vivo and in vitro. Intravenous administration of CGRP (0.01 micrograms/kg) in 6 conscious dogs produced a significant decrease in plasma aldosterone concentration from 68 +/- 12 pg/ml to 28 +/- 11 pg/ml (p less than 0.05) despite a mild but significant elevation of plasma renin activity. In an in vitro study using isolated rabbit adrenal glomerulosa cells CGRP reduced the basal aldosterone secretion in a dose-related manner and furthermore 10(-9) M CGRP inhibited the aldosterone secretion stimulated by 10(-8) M angiotensin II. From these results it is suggested that CGRP has an inhibitory effect on aldosterone secretion.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Aldosterona/sangue , Aldosterona/metabolismo , Animais , Células Cultivadas , Cães , Feminino , Masculino , Concentração Osmolar , Coelhos , Zona Glomerulosa/citologia , Zona Glomerulosa/metabolismo
10.
Hypertension ; 11(6 Pt 2): 750-3, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3391682

RESUMO

The mechanism by which intracerebroventricularly administered aldosterone increases arterial pressure was investigated in trained, conscious dogs with cannulas chronically implanted in a lateral cerebral ventricle. In salt-replete and salt-depleted dogs, artificial cerebrospinal fluid with or without aldosterone (0.05 microgram/kg/hr) was infused intracerebroventricularly for 12 days by an osmotic minipump. A similar dose of aldosterone was infused subcutaneously for 12 days. Aldosterone infused intracerebroventricularly increased blood pressure significantly in both salt-replete and salt-depleted dogs. In salt-replete animals the hypertension was associated with increased total peripheral resistance without concomitant changes in blood volume, cardiac output, or in any of the neurohumoral parameters measured. We conclude that this type of hypertension is resistance-mediated from its outset and appears to be relatively independent of salt and water retention. The mechanism by which intracerebroventricularly administered aldosterone increases vascular resistance remains to be determined.


Assuntos
Aldosterona/toxicidade , Hemodinâmica/efeitos dos fármacos , Hipertensão/fisiopatologia , Aldosterona/administração & dosagem , Hipertensão/induzido quimicamente , Injeções Intraventriculares , Injeções Subcutâneas , Masculino , Sódio na Dieta/administração & dosagem
11.
Hypertension ; 9(6 Pt 2): III166-70, 1987 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2885273

RESUMO

We determined whether dietary calcium supplementation can influence the development and maintenance of hypertension in deoxycorticosterone (DOC)-salt-treated dogs. Dogs on normal dietary calcium (0.4%) had significant increases in mean arterial pressure (from 92 +/- 2 to 131 +/- 3 mm Hg, p less than 0.01); those given high dietary calcium (1.7%) had attenuated but significant increases in mean arterial pressure (from 90 +/- 2 to 107 +/- 1, p less than 0.01). The elevation of blood pressure in dogs on normal dietary calcium was primarily due to increased calculated total peripheral resistance, which was prevented by the high calcium diet. The increases in blood pressure could not be attributed to any changes in cardiac output, blood volume, or plasma norepinephrine. These results suggest that mineralocorticoid hypertension in the dog is associated with abnormalities not only in sodium, but also in calcium metabolism. Further, they suggest a direct link between sodium and calcium metabolism and may thus have implications for the pathogenesis and management of salt-dependent hypertension.


Assuntos
Cálcio da Dieta/uso terapêutico , Hemodinâmica/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Neurotransmissores/metabolismo , Animais , Desoxicorticosterona , Cães , Epinefrina/sangue , Hipertensão/induzido quimicamente , Hipertensão/metabolismo , Masculino , Norepinefrina/sangue , Cloreto de Sódio
12.
Hypertension ; 10(4): 375-82, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3653966

RESUMO

The effects of calcium supplementation on blood pressure and its mechanisms were investigated in two-kidney, one clip renovascular hypertensive rats. Two series of experiments were performed: one was begun just after renal artery constriction, the other after the onset of hypertension. Calcium supplementation significantly attenuated the development of hypertension (systolic blood pressure: 183 +/- 8 vs 130 +/- 2 mm Hg) and was found to abate existing renovascular hypertension (systolic blood pressure: from 183 +/- 8 to 151 +/- 4 mm Hg). Calcium treatment did not cause significant alterations in fluid intake, urine volume, or urinary sodium excretion in either study. However, increased plasma renin activity and plasma aldosterone concentration were suppressed to the basal levels at the end of 3 weeks of calcium treatment (14 +/- 3 vs 8 +/- 2 ng angiotensin I/ml/hr; 530 +/- 50 vs 380 +/- 40 pg/ml). Blood pressure of calcium-treated renovascular hypertensive rats responded poorly to blockade of the renin-angiotensin system with captopril injection and angiotensin II analogue (saralasin) infusion. Further, in rats with chronic established renovascular hypertension, calcium treatment attenuated the enhanced pressor response to norepinephrine, but not to angiotensin II. These results suggest that the blood pressure-lowering actions of calcium supplementation are related primarily to suppression of renin secretion and secondarily to alteration of pressor response to norepinephrine in two-kidney, one clip renovascular hypertensive rats.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Cálcio/administração & dosagem , Hipertensão Renovascular/tratamento farmacológico , Sistema Renina-Angiotensina/efeitos dos fármacos , Administração Oral , Animais , Cálcio/uso terapêutico , Depressão Química , Masculino , Ratos
13.
J Hypertens ; 10(6): 561-9, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1320077

RESUMO

OBJECTIVE: The aim of this study was to investigate the role of depressor systems in glucocorticoid-induced hypertension. METHODS: The serial changes in cardiorenal hemodynamics, urinary excretions of kallikrein and prostaglandins (PGE2 and the prostacyclin derivative 6-keto-PGF1 alpha) before, and during the administration of both low and high doses of dexamethasone (9 alpha-fluoro-16 alpha-methylprednisolone) and after the cessation of dexamethasone were examined in conscious trained dogs. In addition, pressor responses to prostaglandin, bradykinin, bradykinin antagonist and indomethacin were studied during the administration of dexamethasone. RESULTS: High-dose dexamethasone induced a significant elevation in mean arterial pressure (MAP) that was accompanied by a significant reduction in the urinary excretion of kallikrein, PGE2 and 6-keto-PGF1 alpha. In contrast, low-dose dexamethasone treatment had no significant effect upon MAP but induced a transient elevation in the urinary excretion of kallikrein, PGE2 and 6-keto-PGF1 alpha. Furthermore, additional oral administration of indomethacin produced a significant elevation in MAP in dogs treated with low-dose dexamethasone; but did not affect the hemodynamics of animals with high-dose dexamethasone. Whilst i.v. administration of either bradykinin or prostacyclin induced a significant reduction in MAP in high-dose but not low-dose dexamethasone-treated dogs, administration of a competitive bradykinin antagonist, D-Arg-[Hyp3, Thi5,8, D-Phe7]-bradykinin induced a significant elevation in MAP in low-dose but not high-dose dexamethasone-treated dogs. CONCLUSION: Depressor systems play an important role in regulation of blood pressure in glucocorticoid-treated dogs.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Glucocorticoides/administração & dosagem , Hipertensão/etiologia , Animais , Pressão Sanguínea/fisiologia , Bradicinina/administração & dosagem , Bradicinina/análogos & derivados , Dexametasona/administração & dosagem , Cães , Relação Dose-Resposta a Droga , Interações Medicamentosas , Hipertensão/fisiopatologia , Indometacina/administração & dosagem , Sistema Calicreína-Cinina/efeitos dos fármacos , Sistema Calicreína-Cinina/fisiologia , Masculino , Prostaglandinas/fisiologia , Fatores de Tempo
14.
J Hypertens ; 13(10): 1169-79, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8586809

RESUMO

OBJECTIVE: To determine whether the central nervous system has a pressor or a depressor role in glucocorticoid-induced hypertension. METHODS: Intracerebroventricular dexamethasone or its receptor antagonist, RU 38486, was administered in 20 trained conscious dogs. In addition, intracerebroventricular RU 38486 was administered in dogs treated with oral dexamethasone. RESULTS: Intracerebroventricular dexamethasone induced a dose-related reduction in blood pressure accompanied by decreased heart rate and cardiac output. In contrast, intracerebroventricular RU 38486 caused a slight but not significant elevation in blood pressure. Total peripheral resistance showed no significant change throughout the treatment with dexamethasone or RU 38486. In contrast, oral dexamethasone caused significant elevation of blood pressure associated with increased total peripheral resistance and reduced heart rate. In hypertensive dogs treated with oral dexamethasone, intracerebroventricular RU 38486 elicited a more severe form of hypertension accompanied by an attenuation of the heart rate and a reduction in cardiac output. Intracerebroventricular dexamethasone induced a significant reduction in plasma levels of adrenocorticotrophic hormone, cortisol, arginine vasopressin and noradrenaline. In addition, simultaneous central administration of RU 38486 with intracerebroventricular dexamethasone blocked the reduction in blood pressure and heart rate completely. CONCLUSION: The present data strongly suggest that endogenous glucocorticoid in the central nervous system may not have a role in the regulation of systemic haemodynamics and hormones under resting conditions, but does play an important part during the glucocorticoid excess state, for example glucocorticoid hypertension caused by oral treatment with dexamethasone. The glucocorticoid in the central nervous system opposed the elevation of blood pressure in glucocorticoid-induced hypertension by attenuating the reduction in heart rate and cardiac output via direct stimulation of glucocorticoid receptors in the brain.


Assuntos
Sistema Nervoso Central/efeitos dos fármacos , Dexametasona/farmacologia , Glucocorticoides/farmacologia , Hipertensão/induzido quimicamente , Animais , Sistema Nervoso Central/fisiopatologia , Cães , Hemodinâmica , Antagonistas de Hormônios/farmacologia , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Masculino , Mifepristona/farmacologia , Receptores de Glucocorticoides/efeitos dos fármacos , Receptores de Glucocorticoides/fisiologia
15.
J Hypertens ; 13(12 Pt 1): 1405-12, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8866902

RESUMO

OBJECTIVE: To study the different cardiac and renal hemodynamic effects of an angiotensin converting enzyme inhibitor and an angiotensin II receptor antagonist in experimental heart failure in conscious dogs. DESIGN AND METHODS: We compared the effects of the angiotensin converting enzyme inhibitor, captopril, with those of the angiotensin II (Ang II) subtype-1 receptor antagonist, losartan, on hemodynamics and hormonal changes in congestive heart failure by rapid ventricular pacing on conscious dogs. Furthermore, we characterized the Ang II receptors in canine heart, using the canine cardiac membrane fraction in heart failure. RESULTS: Acute intravenous administration of captopril improved the cardiac output by 19% (P < 0.01) but losartan did not, although blockade of the renin-angiotensin system by losartan (1.1 mumol/kg) or captopril (0.69 mumol/kg) induced similar changes in the plasma renin activity, norepinephrine and arginine vasopressin, and a similar decrease in mean arterial pressure (-10 mmHg). Renal blood flow was increased by either losartan or captopril. In the binding study, losartan produced a single displacement curve (IC50 = 0.25 mumol/l), while the Ang II subtype-2 (AT2) receptor antagonist PD123319 did not, indicating that the predominant Ang II receptor is type-1 (AT1) in canine heart. Neither the ratio of AT1 to AT2 receptors nor the receptor density changed with the development of heart failure. CONCLUSIONS: The lack of effect of losartan on cardiac output may be the result of its inability to block non-AT1 receptor-mediated Ang II activities adequately. Captopril may improve cardiac output by means of mechanisms not mediated by Ang II, such as locally increasing bradykinin.


Assuntos
Compostos de Bifenilo/farmacologia , Captopril/farmacologia , Insuficiência Cardíaca/fisiopatologia , Imidazóis/farmacologia , Sistema Renina-Angiotensina/efeitos dos fármacos , Tetrazóis/farmacologia , Angiotensina II/metabolismo , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Ligação Competitiva , Compostos de Bifenilo/metabolismo , Cães , Insuficiência Cardíaca/metabolismo , Hemodinâmica/efeitos dos fármacos , Imidazóis/metabolismo , Losartan , Masculino , Miocárdio/citologia , Miocárdio/metabolismo , Piridinas/metabolismo , Valores de Referência , Tetrazóis/metabolismo
16.
J Hypertens ; 9(4): 337-44, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1646260

RESUMO

The effects of low-dose endothelin on systemic haemodynamics and vasoactive hormones were examined in conscious dogs. In addition, we examined the effects of endothelin on pressor responses to noradrenaline and angiotensin II and the baroreflex regulation of heart rate in conscious dogs. Continuous infusion of 40 fmol/kg per min endothelin for 40 min induced a mild but significant reduction in mean arterial pressure from 89.1 +/- 1.7 to 82.7 +/- 2.0 mmHg (P less than 0.05), associated with decreases in total peripheral resistance 20 min later. A 400 fmol/kg per min dose of endothelin, on the other hand, induced a gradual elevation of mean arterial pressure from 89.2 +/- 2.3 to 96.8 +/- 2.0 mmHg (P less than 0.05), associated with increases in total peripheral resistance over 30 min. The 40 fmol/kg per min dose of endothelin infusion induced a significant reduction in plasma arginine vasopressin (AVP; P less than 0.05) and elevations of plasma atrial natriuretic peptide (ANP; P less than 0.05), plasma prostaglandin E2 (PGE2; P less than 0.05) and plasma 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha; P less than 0.05). The 400 fmol/kg per min dose produced elevations of AVP, ANP, PGE2 and 6-keto-PGF1 alpha (P less than 0.05). Pressor responses to noradrenaline and angiotensin II were significantly attenuated during continuous infusion of 40 fmol/kg per min endothelin, whereas 400 fmol/kg per min endothelin did not induce any significant changes compared with the control. Furthermore, baroreflex sensitivity was attenuated with 40 fmol/kg per min endothelin but did not show any significant changes at 400 fmol/kg per min.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Endotelinas/farmacologia , Hemodinâmica/efeitos dos fármacos , Hormônios/sangue , Angiotensina II/farmacologia , Animais , Arginina Vasopressina/sangue , Fator Natriurético Atrial/sangue , Pressão Sanguínea/efeitos dos fármacos , Estado de Consciência , Cães , Endotelinas/administração & dosagem , Masculino , Norepinefrina/farmacologia , Pressorreceptores/efeitos dos fármacos , Reflexo/efeitos dos fármacos , Sistema Vasomotor/efeitos dos fármacos
17.
J Endocrinol ; 135(1): 147-52, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1431677

RESUMO

It has been suggested that the mineralocorticoid action of glycyrrhizin is caused by a defect in the conversion of cortisol to cortisone through inhibition of the enzyme 11 beta-dehydrogenase (11 beta-DH). We investigated the functional significance of the inhibition of this enzyme as a mechanism of the mineralocorticoid action of glycyrrhizin. Eighteen healthy volunteers were divided into three groups of six and treated as follows: (1) 225 mg glycyrrhizin/day, (2) 0.1 mg 9 alpha-fluorocortisol (FC)/day and (3) 225 mg glycyrrhizin and 1.5 mg dexamethasone/day, all of which were given for 7 days. The administration of glycyrrhizin or FC induced a similar mineralocorticoid effect; specifically, suppression of plasma renin activity, hypokalaemia and kaliuresis. During the concomitant administration of glycyrrhizin and dexamethasone, however, these mineralocorticoid effects were significantly attenuated. During the administration of glycyrrhizin, urinary excretion of cortisol increased without change in the plasma levels of cortisol, while both plasma level and urinary excretion of cortisone decreased. Changes in cortisol metabolism were not observed during the administration of FC. These results demonstrated the functional significance of the inhibition of 11 beta-DH in the mineralocorticoid activity of glycyrrhizin in man.


Assuntos
Ácido Glicirretínico/análogos & derivados , Hidrocortisona/metabolismo , Rim/metabolismo , Mineralocorticoides/farmacologia , Cortisona/metabolismo , Dexametasona/farmacologia , Feminino , Fludrocortisona/farmacologia , Ácido Glicirretínico/farmacologia , Ácido Glicirrízico , Humanos , Rim/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade
18.
Eur J Endocrinol ; 140(1): 62-5, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10037254

RESUMO

A 4-year-old boy with an undescending left testis, penoscrotal hypospadia and bilateral microphthalmia was admitted to our hospital. Chromosome analysis revealed a karyotype of 46, XX del(x)(p2 2,31) and the sex-determining region of the Y chromosome (SRY) was negative. The right testis was located in the scrotum and a left cystic ovary-like gonad, a salpinx and a unicorn uterus were found in the left inguinal canal. Histologically the gonad was an ovotestis in which primordial follicles covered infantile seminiferous tubules. Microphthalmia is observed in some congenital syndromes caused by interstitial deletion of the X chromosome. This case suggested that the short arm of the X chromosome was involved in the differentiation of the gonad. Very closely located follicles and infantile seminiferous tubules indicated that induction of meiosis in the fetus was controlled by the local microenvironment in follicles and seminiferous tubules, and not by the systemic hormonal condition.


Assuntos
Transtornos do Desenvolvimento Sexual/genética , Hipospadia/genética , Microftalmia/genética , Criança , Transtornos do Desenvolvimento Sexual/cirurgia , Feminino , Deleção de Genes , Humanos , Hipospadia/cirurgia , Cariotipagem , Masculino , Microftalmia/cirurgia , Folículo Ovariano/anormalidades , Folículo Ovariano/cirurgia , Túbulos Seminíferos/anormalidades , Túbulos Seminíferos/cirurgia , Aberrações dos Cromossomos Sexuais/genética , Uretra/cirurgia
19.
Insect Biochem Mol Biol ; 24(6): 599-605, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8044175

RESUMO

Athalia rosae (Hymenoptera) was previously shown to have two vitellins (L-Vn and S-Vn) and the two corresponding vitellogenins (L-Vg and S-Vg). A cDNA expression library was constructed from poly(A)+ RNA prepared from adult female fat body cells, and was screened for the vitellogenins by using antisera against the L- and S-Vn, respectively. Examinations of cloned cDNAs show that the vitellogenin gene is transcribed as a single unit, with the 5'-terminal site coding for the S-Vg and the 3'-terminal site for the L-Vg. Nucleotide sequence at the 5'-end suggests the presence of a 16 amino acid-long signal peptide. Deduced amino acid sequence following the signal peptide shows a complete match with up to the 28 N-terminal amino acid sequence determined on S-Vn. The S-L Vg boundary with deduced amino acid sequence matching with 6 N-terminal amino acid sequence determined on L-Vn is also detected. Northern blot hybridization analysis shows that the vitellogenin gene is expressed in the female fat body as a single 6.5 kb mRNA but not in the ovary, and not in the male fat body. Western blot analysis detects a large precursor polypeptide, reacting with the anti-L-Vn and S-Vn antisera, in the adult female fat body.


Assuntos
DNA Complementar , Expressão Gênica , Genes de Insetos/genética , Himenópteros/genética , Vitelogeninas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Corpo Adiposo/química , Feminino , Biblioteca Gênica , Masculino , Dados de Sequência Molecular , Peso Molecular , Precursores de Proteínas/análise , Sinais Direcionadores de Proteínas/genética , RNA Mensageiro/análise , Análise de Sequência , Análise de Sequência de DNA , Vitelogeninas/química
20.
Hypertens Res ; 23(5): 459-66, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11016800

RESUMO

Plasma albumin leaks into urine as a result of glomerular hypertension and basement membrane injury, while urinary type IV collagen derives from mesangial matrix and glomerular basement membrane. The purpose of this study was to elucidate the pathophysiological significance of these urinary microproteins as an indicator of cardiovascular organ injuries in hypertension. In health-checkup participants without diabetes, proteinuria, or microhematuria, and who were not being treated for hypertension or any other disease at the time of enrollment, urinary albumin and type IV collagen were measured and their relations to organ injuries and cardiovascular risk factors were evaluated. Of 1,079 subjects (40- to 65-year-old; 256 men and 823 women) enrolled in the study, 120 (11.1%) had untreated hypertension exceeding 140/90 mmHg. Urinary albumin was positively correlated with both age (r=0.16, p<0.001) and systolic blood pressure (r=0.27, p<0.001). Urinary type IV collagen was not only positively correlated with age (r=0.12, p<0.001) and diastolic blood pressure (r=0.14, p<0.001) but also negatively correlated with blood hemoglobin (r=-0.12, p<0.001). Urinary albumin, but not type IV collagen, had a significant relation to electrocardiographic signs of left ventricular hypertrophy (p=0.012) and retinal arteriosclerosis on fundoscopy (p <0.001). Thus both albumin and type IV collagen would seem to have increased in association with age and hypertension in this cohort. It is suggested that urinary albumin is an indicator not only of renal injury, but also possibly of development of cardiac hypertrophy and arteriosclerotic changes. Urinary type IV collagen, on the other hand, may be associated with renal tissue injuries that affect erythrokinetics.


Assuntos
Albuminúria/urina , Pressão Sanguínea , Colágeno/urina , Hipertensão/urina , Adulto , Idoso , Albuminúria/sangue , Albuminúria/diagnóstico , Arteriosclerose/sangue , Arteriosclerose/diagnóstico , Arteriosclerose/urina , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Ecocardiografia , Feminino , Humanos , Hipertensão/sangue , Hipertensão/diagnóstico , Hipertrofia Ventricular Esquerda/sangue , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/urina , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Análise de Regressão , Triglicerídeos/sangue
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