RESUMO
Tacrolimus (FK506) has a neuroprotective action on cerebral infarction produced by cerebral ischemia, however, detailed mechanisms underlying this action have not been fully elucidated. We examined temporal profiles of survival-and death-related signals, Bad phosphorylation, release of cytochrome c (cyt.c), activation of caspase 3 and DNA fragmentation in the brain during and after middle cerebral artery occlusion (MCAo) in mice, and then examined the effect of tacrolimus on these signals. C57BL/6J mice were subjected to transient MCAo by intraluminal suture insertion for 60 min. Tacrolimus (1 mg/kg, i.p.) was administered immediately after MCAo. There were biphasic increases in the release of cyt.c in the ischemic core and penumbra; with the first increase toward the end of the occlusion period and the second increase 3-12 h after reperfusion. Tacrolimus significantly inhibited the increase of cytosolic cyt.c during ischemia and reperfusion. Phosphorylated Bad, Ser-136 (P-Bad(136)) and Ser-155 (P-Bad(155)) were detected 30 min after MCAo and after reperfusion in the ischemic cortex, respectively. Tacrolimus increased P-Bad(136) during ischemia and prolonged P-Bad(155) expression after reperfusion. Tacrolimus also decreased caspase-3 and terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling-positive cells, and reduced the size of infarct 24 h after reperfusion. Our study provided the first evidence that the neuroprotective action of tacrolimus involved inhibition of biphasic cyt.c release from mitochondria, possibly via up-regulation of Bad phosphorylation at different sites after focal cerebral ischemia and reperfusion.
Assuntos
Citocromos c/metabolismo , Imunossupressores/farmacologia , Ataque Isquêmico Transitório/metabolismo , Tacrolimo/farmacologia , Proteína de Morte Celular Associada a bcl/metabolismo , Análise de Variância , Animais , Western Blotting/métodos , Infarto Encefálico/tratamento farmacológico , Infarto Encefálico/etiologia , Infarto Encefálico/metabolismo , Infarto Encefálico/patologia , Modelos Animais de Doenças , Imuno-Histoquímica/métodos , Imunossupressores/uso terapêutico , Marcação In Situ das Extremidades Cortadas , Ataque Isquêmico Transitório/complicações , Ataque Isquêmico Transitório/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação/efeitos dos fármacos , Tacrolimo/uso terapêutico , Fatores de TempoRESUMO
Sulfation of glycosaminoglycans and glycopeptides was compared in baby hamster kidney (BHK) cells and the polyoma virus transformants (PY-BHK). Cells were incubated with [3H]glucosamine and [35S]sulfate, and the labeled glycosaminoglycans and glycopeptides were isolated by digesting the cell membrane fraction with pronase followed by gel filtration. Each type of glycosaminoglycan in the void volume fraction (Fraction I) and in the included fraction (Fraction II) was determined by sequential enzymatic digestions. The residue was regarded as being glycopeptides. Of the total 3H radioactivities of glycosaminoglycans in Fraction I from BHK cells, 51% were in dermatan sulfate, 23% were in heparan sulfate, 17% were in chondroitin 4- and 6-sulfates, and 9% were in hyaluronate. PY-BHK cells acquired significantly larger amounts of 3H radioactivities in sulfated glycosaminoglycans than did BHK cells on the basis of cell number. On the basis of protein content, there was no such difference due to higher protein content of PY-BHK cells. The degree of sulfation of the glycosaminoglycans, estimated from the ratio of 35S to 3H and by disaccharide analysis, was significantly lower in PY-BHK cells than in BHK cells. Considerable amounts of 35S radioactivities assigned to sulfated glycopeptides were found in Fraction II from both BHK and PY-BHK cells.
Assuntos
Transformação Celular Viral , Glicopeptídeos/metabolismo , Glicosaminoglicanos/metabolismo , Rim/metabolismo , Sulfatos/metabolismo , Animais , Linhagem Celular , Cromatografia em Gel , Cromatografia em Papel , Cricetinae , Glucosamina/metabolismo , Pronase/metabolismoRESUMO
BACKGROUND: The alphaIIbbeta3 antagonists inhibit platelet aggregation and are used as antithrombotic agents for cardiothrombotic disease. The present study investigates the correlation of inhibition of fibrinogen and von Willebrand factor (VWF) binding by alphaIIbbeta3 antagonists with the inhibition of platelet aggregation and prolongation of bleeding time (BT). METHODS: Inhibition of fibrinogen and VWF binding were assessed in a purified alphaIIbbeta3-binding assay. As an in vitro cell-based assay, platelet aggregation and VWF-mediated adhesion studies were performed using human platelets. In vivo effects on BT were measured using a template device in dogs at the same time as an ex vivo aggregation study was performed. RESULTS: In vitro studies demonstrated that the antiaggregatory effects of alphaIIbbeta3 antagonists correlate with their inhibition of fibrinogen binding, but not VWF. Interestingly, the effects of alphaIIbbeta3 antagonists on BT could be differentiated from the inhibition of platelet aggregation. Furthermore, this differentiation was strongly correlated with the different inhibitory potencies between fibrinogen and VWF binding, as well as that between VWF-mediated adhesion and aggregation. CONCLUSIONS: Our study provides novel evidence showing that the inhibitory effect of alphaIIbbeta3 antagonists on VWF, but not fibrinogen binding, correlates with their ability to prolong BT.
Assuntos
Plaquetas/fisiologia , Fibrinogênio/antagonistas & inibidores , Hemorragia/etiologia , Inibidores da Agregação Plaquetária/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Fator de von Willebrand/antagonistas & inibidores , Animais , Testes de Coagulação Sanguínea , Cães , Fibrinogênio/metabolismo , Humanos , Cinética , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Fator de von Willebrand/metabolismoRESUMO
Heparin has been known to induce osteopenia, but its precise mechanism of action is unknown. In the present study, we examined the effect of heparin on the rat femur using single photon absorptiometry and characterized the osteopenia biochemically and pharmacologically. Daily heparin injection dose dependently induced osteopenia in rats. Significant bone loss was observed from 2 weeks after starting heparin treatment (2000 U/kg.day) and peaked at 4 weeks. Serum PTH levels were significantly elevated from 1 week onward after starting heparin treatment, whereas no significant changes were seen in serum total calcium or ionized calcium levels. A bone resorption inhibitor, FR78844 (a bisphosphonate compound), significantly attenuated the heparin-induced osteopenia, as did 1 alpha-hydroxyvitamin D3; with the latter, the effective dose was 10 times lower than that needed for a similar effect against immobilization and ovariectomy-induced osteopenia, suggesting an up-regulation of 1 alpha, 25-dihydroxyvitamin D3 receptors in the heparin-treated rats. This speculation was supported by the finding that serum 1 alpha, 25-dihydroxyvitamin D levels were significantly decreased by 54% in the heparin-treated rats compared to those in normal rats. These results suggest that the enhanced bone resorption by high PTH blood levels and the reduction of 1 alpha, 25-dihydroxyvitamin D are involved in the pathogenesis of heparin-induced osteopenia.
Assuntos
Doenças Ósseas Metabólicas/induzido quimicamente , Heparina , Absorciometria de Fóton , Animais , Doenças Ósseas Metabólicas/metabolismo , Doenças Ósseas Metabólicas/patologia , Calcificação Fisiológica/efeitos dos fármacos , Calcitriol/sangue , Difosfonatos/farmacologia , Feminino , Hidroxicolecalciferóis/farmacologia , Técnicas de Cultura de Órgãos , Ovariectomia , Hormônio Paratireóideo/sangue , Ratos , Ratos Wistar , Crânio/efeitos dos fármacos , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/metabolismoRESUMO
Plasma homovanillic acid (pHVA) levels were measured and the Brief Psychiatric Rating Scale (BPRS) scores were evaluated in 26 schizophrenic patients who had either never been medicated (neuroleptic-naive, first-episode subjects) or whose condition had become exacerbated following neuroleptic discontinuance (exacerbated subjects). All the subjects received medication with a fixed dose of a neuroleptic (haloperidol or fluphenazine, both 9 mg/day) for the first week and variable doses for the subsequent 4 weeks. In the neuroleptic-naive subjects, pHVA levels increased significantly 1 week after starting the protocol; this increase correlated significantly with clinical improvement of the BPRS positive symptom scores at week 5. In the neuroleptic-naive subjects, pHVA levels had declined to the baseline level by week 5. In the exacerbated subjects, there were no significant correlations between pHVA level changes at week 1 and later improvements of the BPRS positive symptom scores. These results suggest that the rise in pHVA levels occurring within 1 week after starting a fixed neuroleptic dose may predict a favorable clinical response in neuroleptic-naive schizophrenic patients.
Assuntos
Antipsicóticos/uso terapêutico , Flufenazina/uso terapêutico , Haloperidol/uso terapêutico , Ácido Homovanílico/sangue , Esquizofrenia/sangue , Esquizofrenia/tratamento farmacológico , Adulto , Análise de Variância , Escalas de Graduação Psiquiátrica Breve , Feminino , Humanos , Masculino , Esquizofrenia/fisiopatologia , Estatísticas não Paramétricas , Resultado do TratamentoRESUMO
Nilvadipine and other calcium antagonists were studied for their effect on 1-alpha-hydroxyvitamin D3 (1 - alpha (OH)D3)-induced aortic calcium deposition in rats. The animals were treated orally with 1-alpha (OH)D3 (10 micrograms/kg) for 2 weeks. Calcium antagonists were given orally twice a day during the same period. The aortic calcium content in 1-alpha (OH)D3-treated rats increased to about 100 times that in the control. Nilvadipine reduced the aortic calcium deposition dose-dependently, with percent inhibition of 6, 43, 72 and 92%, at doses of 0.1, 1, 10 and 100 mg/kg, respectively. Similar activities were obtained for the other calcium antagonists except diltiazem which had no effect even at the largest dose of 100 mg/kg. According to the ED50 values, nilvadipine (2.2 mg/kg) was more potent than nifedipine (23.2 mg/kg), nicardipine (12.4 mg/kg) and verapamil (32.0 mg/kg). Scanning and transmission electron microscopy showed clear-cut degenerative changes in the endothelial cells after 1-alpha (OH)D3 treatment. Nilvadipine exerted a protective effect against these degenerative changes but not against 1-alpha (OH)D3-induced hypercalcemia. Furthermore, the drug had only minimal effect on in vitro calcification of the aorta. Our findings suggest that nilvadipine inhibits aortic calcification by protecting the aortic wall cells.
Assuntos
Aorta Torácica/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Cálcio/metabolismo , Nifedipino/análogos & derivados , Animais , Aorta Torácica/patologia , Aorta Torácica/ultraestrutura , Arteriosclerose/etiologia , Arteriosclerose/metabolismo , Cálcio/sangue , Relação Dose-Resposta a Droga , Ergocalciferóis/análogos & derivados , Ergocalciferóis/farmacologia , Técnicas In Vitro , Masculino , Microscopia Eletrônica de Varredura , Nifedipino/farmacologia , Ratos , Ratos Endogâmicos F344RESUMO
The chemotactic activities of inflammatory cell products for rat aortic smooth muscle cells (SMC) were examined in modified Boyden chambers. A checker board analysis revealed that interleukin-1 (IL-1), leukotriene B4 (LTB4), platelet-derived growth factor (PDGF) and inflammatory exudate from zymosan-activated air pouches stimulated chemotaxis of SMC. The chemotaxis, irrespective of the attractants used, was strongly inhibited by nilvadipine, a potent calcium antagonist, and the IC50 values were around 1 x 10(-10) M. Removal of extracellular calcium abolished the chemotactic activities of the attractants. These results suggest that inflammatory cells such as macrophages and polymorphonuclear leukocytes (PMN) have an important role in the migration of SMC into the intima during atherogenesis, and that nilvadipine might be useful for preventing and treating atherosclerosis.
Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Quimiotaxia/efeitos dos fármacos , Inflamação/fisiopatologia , Músculo Liso Vascular/fisiologia , Nifedipino/análogos & derivados , Animais , Aorta Torácica/fisiopatologia , Cálcio/farmacologia , Células Cultivadas , Exsudatos e Transudatos , Interleucina-1/farmacologia , Leucotrieno B4/farmacologia , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Nifedipino/farmacologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Ratos , Ratos EndogâmicosRESUMO
Immediately after a cuff-sheathing of rabbit carotid artery, a large number of leukocytes adhered to injured endothelium then infiltrated into the media. These inflammatory responses were followed by an atherosclerotic change, intimal thickening, of the artery. A simultaneous injection of dexamethasone (10 mg/kg i.m.) inhibited the leukocyte accumulation by 74% when evaluated 18 h thereafter. Similarly, 39% inhibition was obtained with the same dose of FR110302, a potent 5-lipoxygenase inhibitor. On the other hand, the same dose of indomethacin, a cyclooxygenase inhibitor, had little effect on the leukocyte accumulation. The intimal thickening which was evaluated 3 weeks after the cuff-treatment was attenuated by a daily dose (10 mg/kg i.m.) of dexamethasone or FR110302 but not by one of indomethacin. The inhibition by the two former drugs were 91 and 58%, respectively. In vitro, the three drugs in concentrations up to 10 microM hardly affected endothelial adhesion of PMN which was induced by LPS or IL-1. Though 10 microM of FR110302 and indomethacin significantly decreased PMN chemotaxis induced by LTB4, the decreases were less than that at 10 microM dexamethasone. These results confirm a possible linkage between inflammation and atherosclerosis, and suggest that 5-lipoxygenase products contribute to the initiation and development of atherosclerosis.
Assuntos
Anti-Inflamatórios/farmacologia , Arteriosclerose/patologia , Artérias Carótidas/patologia , Neutrófilos/patologia , Animais , Arteriosclerose/fisiopatologia , Artérias Carótidas/ultraestrutura , Adesão Celular , Movimento Celular , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Endotélio Vascular/patologia , Endotélio Vascular/ultraestrutura , Indometacina/farmacologia , Inflamação/patologia , Masculino , Microscopia Eletrônica de Varredura , Naftóis/farmacologia , Neutrófilos/fisiologia , Neutrófilos/ultraestrutura , Quinolinas/farmacologia , CoelhosRESUMO
The antiatherogenic activity of FR34235 (Nilvadipine), a calcium antagonist, was examined in rabbits with carotid arteries sheathed with polyethylene cuffs, and compared with that of nifedipine, verapamil and diltiazem. The drugs were given intramuscularly in daily doses of 0.01-10 mg/kg for 3 weeks, starting on the day of cuff-placement. FR34235 dose-dependently inhibited the cuff-induced intimal thickening, and was more potent than the other calcium antagonists, whose order of potency was nifedipine, diltiazem and verapamil. In an in vitro experiment on inhibition of migration of rat aortic smooth muscle cells, using zymosan-activated air pouch exudate as a chemoattractant in modified Boyden chambers, FR34235 was also the most potent among the calcium antagonists tested. The IC50 values were 3.3 X 10(-11) M for FR34235, 1.7 X 10(-10) M for nifedipine, 6.0 X 10(-9) M for verapamil and 2.4 X 10(-7) M for diltiazem. Effects of these drugs on proliferation of rat aortic smooth muscle cells and rabbit platelet aggregation were also examined in vitro. At concentrations less than 10(-5) M, none of the drugs inhibited proliferation of the smooth muscle cells, and only verapamil inhibited collagen-induced platelet aggregation (IC50 = 9.0 X 10(-7) M). It is suggested that FR34235 should be useful for preventing and treating atherosclerosis. Inhibition of smooth muscle cell migration is thought to be its mechanism of antiatherogenic activity.
Assuntos
Arteriosclerose/prevenção & controle , Bloqueadores dos Canais de Cálcio/farmacologia , Artérias Carótidas/efeitos dos fármacos , Doenças das Artérias Carótidas/prevenção & controle , Músculo Liso Vascular/efeitos dos fármacos , Nifedipino/análogos & derivados , Animais , Arteriosclerose/patologia , Artérias Carótidas/patologia , Doenças das Artérias Carótidas/patologia , Masculino , Músculo Liso Vascular/patologia , Nifedipino/farmacologia , Nifedipino/uso terapêutico , CoelhosRESUMO
Cuff-treatment of the rabbit carotid artery produced a diffuse intimal thickening which resembled early lesions of atherosclerosis. A limited amount of focal endothelial damage occurred first (0.5 h), leukocytes infiltrated the subendothelium and extensive endothelial denudation occurred at 24 h. At 3 days, the regenerating endothelium covered the denuded area, and the media was edematous. At 7 days proliferation of intimal cells became visible. Maximum intimal thickening occurred at 3 weeks. Daily injection of dexamethasone (0.01-10 mg/kg i.m.) and ticlopidine (1-100 mg/kg i.m.) dose-dependently attenuated the intimal thickening. Indomethacin had little effect. Inflammatory exudate from zymosan-activated air pouch induced chemotaxis of rat smooth muscle cells (SMC) in vitro. Similar chemotactic activity was observed with leukotriene B4 (LTB4) but not with the other lipoxygenase products tested. The exudate contained reasonable amounts of LTB4, which would account for its chemotactic activity. Dexamethasone inhibited the chemotaxis by the exudate and proliferation of SMC. These results are discussed in relation to the mechanism of atherogenesis. It is concluded that leukocytes play a major role in cuff-induced intimal thickening, and that their products cause endothelial denudation and SMC chemotaxis. Involvement of platelet aggregation in atherogenesis is also suggested.
Assuntos
Arteriosclerose/patologia , Doenças das Artérias Carótidas/patologia , Músculo Liso Vascular/patologia , Animais , CoelhosRESUMO
Two cases of anomalous systemic arterial supply to the basal segments of the lower lobe of the left lung without sequestration are presented. In the first case, the final diagnosis was made during a surgical operation, and lobectomy of the lower lobe of the left lung was performed. In the second case, the preoperative diagnosis made by CT was confirmed by angiography. An anastomosis was performed between the anomalous artery and the pulmonary artery without resection of the basal segments. Six months after surgery, pulmonary angiography showed improved flow of the anastomosed vessel, but little improvement was evidenced in the perfusion scan.
Assuntos
Pulmão/irrigação sanguínea , Adulto , Anastomose Cirúrgica , Angiografia , Aorta Torácica/anormalidades , Artérias/anormalidades , Artérias/cirurgia , Técnicas de Diagnóstico por Cirurgia , Humanos , Masculino , Pneumonectomia , Artéria Pulmonar/cirurgia , Circulação Pulmonar , Tomografia Computadorizada por Raios XRESUMO
Plasma membranes were isolated from an ascites hepatoma, AH 130 FN, a free-cell type subline of AH 130, by the fluorescein mercuric acetate (FMA) method. Glycopeptides and mucopolysaccharides were prepared from the membranes by pronase digestion then fractionated chromatographically and electrophoretically. Isolated fractions were analyzed for amino acid and carbohydrate compositions. The results were compared with those for corresponding fractions from AH 66 and AH 130 ((1974) J. Biochem. 76, 319-333; (1975) ibid., 78, 863-872). The fraction excluded from Sephadex G-50 contained mucopolysaccharides and a series of glycopeptides. The mucopolysaccharides were identified as chondroitin sulfate A on the basis of their chemical composition, electrophoretic behavior on cellulose acetate and digestibility with chondroitinase AC [EC 4.2.2.5]. This contrasts with previous findings that mucopolysaccharides from the corresponding fractions from AH 130 and AH 66 were heparan sulfate. The chemical composition of the glycopeptides, which showed high contents of threonine, serine, galactose, galactosamine, glucosamine, and sialic acid, indicated the presence of glycopeptides with O-glycosidic linkages. The glycopeptides also contained a small but significant amount of aspartic acid, suggesting that N-glycosidic glycopeptides were also contained in this fraction. The fraction included in Sepnadex G-50 contaoned N-glycosidic glycopeptides as major components, since the carbohydrate moieties were composed of fucose, galactose, mannose, glucosamine, sialic acid, and a smaller amount of galactosamine. The presence of galactosamine suggested that O-glycosidic glycopeptides were present as minor components. Glycopeptides with both O- and N-glycosidic linkages were isolated from AH 130, but not from AH 66.
Assuntos
Carcinoma Hepatocelular/análise , Membrana Celular/análise , Glicopeptídeos/isolamento & purificação , Glicosaminoglicanos/isolamento & purificação , Neoplasias Hepáticas/análise , Aminoácidos/análise , Animais , Células Cultivadas , Feminino , Hexoses/análise , Ratos , Ácidos Siálicos/análiseRESUMO
A proteoglycan was isolated from plasma membranes prepared from AH 66 cells by the following procedure. The plasma membranes were isolated from cells according to the method devised by Funakoshi and Yamashina (1976) J. Biochem. 80, 1185-1193), then the membranes were made lipid-free. The lipid-free membranes were solubilized with 5 mM sodium phosphate buffer, pH 7.0, containing 0.5% sodium dodecyl sulfate (SDS), then the solution was fractionated on a Sepharose CL 6B column. The proteoglycan eluted near the void volume fraction was further purified by repeated precipitation with cetylpyridinium chloride (CPC). The proteoglycan isolated was homogeneous on electrophoresis on a cellulose acetate strip and was identified as proteoheparan sulfate. The preparation contained 10.6% protein, its amino acid composition being characterized by high contents of glutamic acid, aspartic acid, proline, glycine, threonine, and serine.
Assuntos
Neoplasias Hepáticas Experimentais/análise , Proteoglicanas/isolamento & purificação , Aminoácidos/análise , Animais , Membrana Celular/análise , Heparitina Sulfato/isolamento & purificação , Hexosaminas/análise , Proteínas de Neoplasias/análiseRESUMO
We studied the effects of zenarestat, an aldose reductase inhibitor (ARI), on peripheral neuropathy in Zucker diabetic fatty (ZDF) rats, an animal model of type 2 diabetes. ZDF rats and their lean rats counterparts were fed a sucrose-containing diet, and zenarestat was given orally once a day for 8 weeks. Motor nerve conduction velocity (MNCV), F-wave minimal latency (FML), and sorbitol concentrations in the sciatic nerve were measured. In ZDF control rats, a remarkable accumulation of sorbitol, a delay in FML, and a slowing of MNCV were observed compared with lean rats. At a dose of 3.2 mg/kg, zenarestat had no significant effect on the delay in FML and the slowing of MNCV, although the sorbitol accumulation in the sciatic nerve was partially inhibited in ZDF rats. On the other hand, 32 mg/kg zenarestat treatment improved these nerve dysfunctions in ZDF rats, along with a reduction of nerve sorbitol accumulation almost to the level of lean rats. These data showed that zenarestat improved diabetic peripheral neuropathy in ZDF rats, a type 2 diabetes model, providing evidence for the therapeutic potential of zenarestat for the treatment of diabetic neuropathy.
Assuntos
Aldeído Redutase/antagonistas & inibidores , Neuropatias Diabéticas/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Quinazolinas/uso terapêutico , Animais , Glicemia/análise , Peso Corporal , Diabetes Mellitus Tipo 2/complicações , Neuropatias Diabéticas/complicações , Neuropatias Diabéticas/fisiopatologia , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Masculino , Quinazolinas/farmacologia , Ratos , Ratos ZuckerRESUMO
An enzyme-linked immunosorbent assay (ELISA) for measuring human protein C by using two monoclonal antibodies directed toward the heavy chain of protein C is reported. This assay enabled the determination of protein C in concentrations of 10 to 400 ng/ml in less than 3 hours with a single antigen-antibody reaction. Within-run and between-run coefficients of variation were less than 8%. The mean concentrations of protein C in plasma of 42 normal subjects, 24 patients with liver disease, 27 with DIC, 48 with warfarin therapy and 15 with congenital protein C deficiency, were 4.2, 3.0, 2.3, 2.1 and 1.9 micrograms/ml, respectively. The results obtained with the present ELISA correlated well with those of radioimmunoassay (r = 0.935, n = 81) as well as those of Laurell's Rocket method (r = 0.910, n = 81) by using rabbit anti-human protein C serum. The present method was sensitive and specific for measurement of protein C and also PIVKA-protein C in plasma.
Assuntos
Biomarcadores , Ensaio de Imunoadsorção Enzimática , Glicoproteínas/análise , Técnicas Imunoenzimáticas , Anticorpos Monoclonais/imunologia , Coagulação Intravascular Disseminada/sangue , Feminino , Glicoproteínas/deficiência , Glicoproteínas/imunologia , Humanos , Técnicas Imunológicas , Hepatopatias/sangue , Masculino , Proteína C , Precursores de Proteínas/análise , Protrombina/análise , Varfarina/uso terapêuticoRESUMO
To explore the pathogenesis of non-insulin-dependent diabetes mellitus associated osteopenia, we examined age-related changes of the femur metaphyseal bone mineral density in genetically diabetic (db/db) mice and non-diabetic (+/+) mice of the same strain using single photon absorptiometry and characterized the osteopenia pharmacologically and biochemically. Bone mineral density increased with age in the +/+ mice from 5 to 16 weeks of age, but reached a plateau in the db/db mice at 8 weeks of age, and significant differences between the two groups were observed after 12 weeks of age. Ash weight (A) and dry weight (D) of the femur and A/D ratio were significant lower in the db/db mice than in the +/+ mice after 8 weeks of age. Significant elevations of serum calcium and parathyroid hormone (PTH) were observed after 8 weeks and 12 weeks of age, respectively. Serum 1alpha,25-dihydroxyvitamin D levels were significantly decreased in the db/db mice compared to the +/+ mice. Daily oral treatment with 1alpha-hydroxyvitamin D3 (1alpha-(OH)D3) for 4 weeks starting from 8 weeks of age significantly attenuated the bone loss in the db/db mice. These results suggest that an impaired bone mineralization probably by insufficient vitamin D activity and high PTH levels are involved in the osteopenia in the db/db mice. 1alpha-(OH)D3 exerted beneficial effects on the bone loss.
Assuntos
Densidade Óssea/efeitos dos fármacos , Doenças Ósseas Metabólicas/tratamento farmacológico , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/complicações , Hidroxicolecalciferóis/uso terapêutico , Absorciometria de Fóton , Animais , Glicemia/análise , Doenças Ósseas Metabólicas/etiologia , Calcitriol/sangue , Cálcio/sangue , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Tipo 2/genética , Modelos Animais de Doenças , Feminino , Fêmur/fisiologia , Hidroxicolecalciferóis/farmacologia , Insulina/sangue , Camundongos , Camundongos Endogâmicos C57BL , Hormônio Paratireóideo/sangueRESUMO
To explore the pathogenesis of diabetes associated osteopenia, we characterized the osteopenia in streptozotocin (STZ)-diabetic rats pharmacologically and biochemically. The femur metaphyseal bone mineral density measured by single photon absorptiometry decreased time-dependently in the STZ rats compared with that in control, and the difference reached statistical significance from 2 weeks after treatment with STZ. Closely similar bone loss was obtained in ovariectomized (Ovx) and vitamin D deficient(D(-)) rats. Daily oral treatment with a bone resorption inhibitor, FR78844 (a bisphosphonate compound, 100 mg/kg), for 4 weeks significantly attenuated the osteopenia in the STZ and Ovx rats, but not in the D(-) rats, while 1 alpha-hydroxyvitamin D3 (1 alpha-(OH)D3) significantly attenuated the osteopenia in the STZ and D(-) rats in a dose of 0.1 microgram/kg/day, and that in the Ovx rats in 1 microgram/kg/day. The latter dose of 1 alpha-(OH)D3 significantly increased the metaphyseal bone mineral density of the femur in normal rats. Serum levels of 1 alpha, 25-dihydroxyvitamin D (1 alpha, 25-(OH)2D), the most active metabolite of vitamin D, hardly changed in the Ovx rats compared with that in control, but decreased to 24 and 76% that of control in the STZ and D(-) rats, respectively. Serum PTH levels in the STZ, Ovx and D(-) rats were comparable with those in controls, but serum calcitonin levels were reduced to 60 and 66% of control in the STZ and Ovx rats, respectively. Serum osteocalcin levels also decreased in the STZ rats compared to control. It is thus speculated that the predominance of bone resorption over bone formation and the reduction of 1 alpha, 25-(OH)2D are involved in the pathogenesis of diabetes associated osteopenia.
Assuntos
Doenças Ósseas Metabólicas/etiologia , Reabsorção Óssea/complicações , Diabetes Mellitus Experimental/fisiopatologia , Deficiência de Vitamina D/complicações , Animais , Densidade Óssea , Reabsorção Óssea/prevenção & controle , Colecalciferol/deficiência , Diabetes Mellitus Experimental/complicações , Difosfonatos/uso terapêutico , Feminino , Hidroxicolecalciferóis/sangue , Hidroxicolecalciferóis/uso terapêutico , Ovariectomia , Ratos , Ratos Wistar , Estreptozocina , Deficiência de Vitamina D/tratamento farmacológicoRESUMO
Recent studies have shown that acyl-CoA:cholesterol acyltransferase (ACAT) plays an important role in the initiation of diabetes-associated hypercholesterolemia. To confirm this hypothesis, effects of a potent ACAT inhibitor, FR145237, on diet-induced hypercholesterolemia were examined in streptozotocin (STZ)-induced diabetic rats. One-week feeding of 1% cholesterol and 0.5% cholic acid to normal rats and STZ-induced diabetic rats increased plasma cholesterol levels in both groups, and the response was more remarkable in the STZ rats than in the normal ones (1266 +/- 476 mg/dl and 146 +/- 7 mg/dl, respectively). FR145237 dose-dependently reduced the rise in plasma cholesterol levels in the STZ rats and the levels were almost normalized by treatment with 1 mg/kg/day of the compound. These results suggest that hyperresponse to dietary cholesterol was induced in the STZ rats and that ACAT is involved in the hyperresponse. The effects of FR145237 on other plasma lipids such as high density lipoprotein (HDL) cholesterol and triglyceride (TG) levels were also examined.
Assuntos
Benzofuranos/farmacologia , Diabetes Mellitus Experimental/complicações , Hipercolesterolemia/etiologia , Compostos de Fenilureia/farmacologia , Esterol O-Aciltransferase/metabolismo , Animais , Glicemia/análise , Peso Corporal/efeitos dos fármacos , Colesterol/sangue , Colesterol na Dieta/administração & dosagem , HDL-Colesterol/sangue , Diabetes Mellitus Experimental/enzimologia , Ingestão de Alimentos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/enzimologia , Masculino , Ratos , Ratos Sprague-Dawley , Esterol O-Aciltransferase/antagonistas & inibidores , Triglicerídeos/sangueRESUMO
FK506 is an immunosuppressant for organ transplantation in the same clinical settings as cyclosporine (CsA). In the management of liver transplantation, FK506 has advantages over CsA, in terms of rejection and corticosteroid requirements. Recent clinical findings in liver transplant patients indicate that FK506, but not CsA, stimulates choleresis, suggesting that FK506 treatment may accelerate recovery from cholestatic dysfunction through its choleretic action. Recently, we demonstrated in rats that exogenous treatment with insulin-like growth factor I (IGF-I) results in an increase in bile flow and also that FK506 has the potential to increase hepatic production of IGF-I. However, circulating levels of IGF-I in FK506-treated rats were only 30% higher than in nontreated rats. In this study, we evaluated the combined effect of treatment with both IGF-I and FK506 on bile flow in rats to explore the possibility that combination treatment in liver transplant patients could enhance the choleretic action of FK506, benefiting the transplanted liver. Combination treatment of IGF-I with FK506 resulted in a potent and long-lasting increase in bile flow. Overall, this study demonstrated that IGF-I treatment enhanced the choleretic action of FK506, providing potential clinical utility for combination therapy using these two drugs, in treatment after liver transplantation.
Assuntos
Colagogos e Coleréticos/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Tacrolimo/farmacologia , Animais , Colestase/induzido quimicamente , Sinergismo Farmacológico , Humanos , Imunossupressores/farmacologia , Imunossupressores/toxicidade , Ratos , Proteínas Recombinantes/farmacologia , Tacrolimo/toxicidadeRESUMO
Immunomodulatory effects of daily low-dose cisplatin treatment were investigated on compromised patients with advanced or recurrent gastrointestinal cancer. One case of esophageal cancer, 7 of gastric cancer, 2 of colorectal cancer, 1 of carcinomatous peritonitis from unknown origin, and 1 of hepatocellular carcinoma, were treated by daily low-dose cisplatin combined with 5-FU or tegafur, and their ECOG Performance Status Score (PS), number of lymphocytes, and CD3 zeta chain expression of peripheral blood lymphocytes were studied to compare with the effects of treatment. Seven patients with esophageal cancer and gastric cancer showed a partial response and their PS was improved, and the number of lymphocytes and CD3 zeta chain expression of lymphocytes was increased. However, in two patients with progressive disease, a decreased number of lymphocytes and less expression of CD3 zeta chain were seen.