RESUMO
PURPOSE: In this study we wanted to observe the improvement in the healing of periodontal tissues in a group of diabetic patients treated with traditional methods compared to another group treated with the addition of oxygen.The potential of oxygen has long been known in the field of plastic surgery, where it is used to treat burns and skin lesions. MATERIALS AND METHODS: This study consists in a split mouth study which involved 30 patients. We carefully treated them with periodontal therapy using manual and mechanical instrumentation. Then, we applied oxygen in half mouth according to randomization list. Finally we checked up patients after some weeks. RESULTS: Our results highlight that all areas treated with oxygen application healed more rapidly and better than no treated areas. CONCLUSIONS: All in all, we have demonstrated that oxygen can improve the outcome of non-surgical periodontal treatment in diabetic subjects.
RESUMO
Aging is characterized by an impaired capacity to maintain the redox balance both in physiological and pathological situations associated with an increased production of reactive oxygen species. Since the extent of this phenomenon may be influenced by an antioxidants-rich diet, we investigated the effect of supplementation with fresh red orange juice (ROJ) on biochemical and cellular biomarkers of oxidative stress in healthy, trained elderly women after a single bout of exhaustive exercise (EE). To this purpose, a sample of 22 females, 15 (69.0 ± 5.1 years) taking the ROJ supplementation and 7 (68.1 ± 2.7 years) as Control group, was constituted. Blood samples were collected immediately before, 30 minutes, and 24 hr after a single bout of EE, at baseline and after 4 weeks. Our results demonstrate that markers of DNA damage or apoptosis were not affected by EE both in Control and ROJ group, and by ROJ, whereas, exercise temporarily affected the redox balance in both groups. Controls didn't change their response to EE after the experimental period, but experimental group after ROJ supplementation had lower EE-induced MDA, consumed less ascorbic acid, and had less activation of the hypoxanthine/xanthine system, i.e., they seemed to be protected from hypoxia/reoxygenation mechanisms.
Assuntos
Antioxidantes/administração & dosagem , Bebidas , Citrus sinensis/química , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Administração Oral , Idoso , Ácido Ascórbico/sangue , Biomarcadores/sangue , Dano ao DNA , Suplementos Nutricionais , Exercício Físico , Feminino , Hemólise , Homeostase/efeitos dos fármacos , Humanos , Hipoxantina/sangue , Malondialdeído/sangue , Pessoa de Meia-Idade , Oxirredução , Esforço Físico , Xantina/sangueRESUMO
BACKGROUND: An increased frequency of primary hyperparathyroidism (PHP) has been reported in patients with treated breast cancer (BC). PHP has been found in about 7% of BC patients after surgery and radio-, chemio- or hormonal therapy. AIM: To evaluate the frequency of PHP in untreated BC patients. SUBJECTS AND METHODS: We evaluated 186 women with BC and 233 women with thyroid cancer (TC, no.=122) or benign thyroid diseases (BTD, no.=111). In all patients, serum calcium, albumin, PTH, and 25-hydroxyvitamin D (25-OH vitD) were measured before any treatment. RESULTS: Serum calcium concentrations were significantly higher in BC than in TC and BTD groups (median values 9.5 mg/dl, 9.3 mg/dl and 9.3 mg/dl, respectively) but, according to a logistic regression model, calcium was not significantly different between the 3 groups when age was taken into account. In all patients, serum calcium was in the normal range, indicating that no case of overt PHP was present. Five patients (1 in BC, 2 in TC, and 2 in BDT groups) had serum calcium close to the upper limit of normal range, high PTH and low 25-OH vitD, indicating a possible PHP with hypercalcemia masked by concomitant 25-OH vitD deficiency. CONCLUSIONS: In untreated BC group, no patient had overt PHP and 1/186 (0.5%) presented a possible PHP masked by 25-OH vitD deficiency, a PHP frequency much lower than that observed in treated BC patients. These data suggest that the treatments of BC may be responsible for the increased frequency of PHP reported in previous studies.
Assuntos
Neoplasias da Mama/complicações , Hiperparatireoidismo Primário/epidemiologia , Adenoma/sangue , Adenoma/complicações , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/sangue , Cálcio/sangue , Feminino , Bócio Nodular/sangue , Bócio Nodular/complicações , Humanos , Hiperparatireoidismo Primário/complicações , Itália/epidemiologia , Modelos Logísticos , Pessoa de Meia-Idade , Risco , Neoplasias da Glândula Tireoide/sangue , Neoplasias da Glândula Tireoide/complicaçõesRESUMO
The short stature homeobox-containing (SHOX) gene lies in the pseudoautosomal region 1 (PAR1) that comprises 2.6 Mb of the short-arm tips of both the X and Y chromosomes. It is known that its heterozygous mutations cause Leri-Weill dyschondrosteosis (LWD) (OMIM #127300), while its homozygous mutations cause a severe form of dwarfism known as Langer mesomelic dysplasia (LMD) (OMIM #249700). The analysis of 238 LWD patients between 1998 and 2007 by multiple authors shows a prevalence of deletions (46.4%) compared to point mutations (21.2%). On the whole, deletions and point mutations account for about 67% of LWD patients. SHOX is located within a 1000 kb desert region without genes. The comparative genomic analysis of this region between genomes of different vertebrates has led to the identification of evolutionarily conserved non-coding DNA elements (CNE). Further functional studies have shown that one of these CNE downstream of the SHOX gene is necessary for the expression of SHOX; this is considered to be typical "enhancer" activity. Including the enhancer, the overall mutation of the SHOX region in LWD patients does not hold in 100% of cases. Various authors have demonstrated the existence of other CNE both downstream and upstream of SHOX regions. The resulting conclusion is that it is necessary to reanalyze all LWD/LMD patients without SHOX mutations for the presence of mutations in the 5'- and 3'-flanking SHOX regions.
Assuntos
Proteínas de Homeodomínio/genética , Mutação/genética , Cromossomos Humanos X/genética , Cromossomos Humanos Y/genética , Feminino , Transtornos do Crescimento/genética , Humanos , Masculino , Osteocondrodisplasias/genética , Proteína de Homoeobox de Baixa EstaturaRESUMO
AIM: Rhodiola Rosea, is an adaptogen plant which has been reported to promote fatty acids utilisation, to ameliorate antioxidant function, and to improve body resistance to physical strenuous efforts. The purpose of the present study was to investigate the effects on physical performance as well as on the redox status of a chronic Rhodiola Rosea supplementation in a group of competitive athletes during endurance exercise. METHODS: Following a chronic supplementation with Rhodiola Rosea for 4 weeks, 14 trained male athletes underwent a cardio-pulmonary exhaustion test and blood samples to evaluate their antioxidant status and other biochemical parameters. These data were compared with those coming from the same athletes after an intake of placebo. RESULTS: The evaluation of physical performance parameters showed that HR Max, Borg Scale level, VO(2) max and duration of the test were essentially unaffected by Rhodiola Rosea assumption. On the contrary, Rhodiola Rosea intake reduced, in a statistically significative manner, plasma free fatty acids levels. No effect on blood glucose was found. Blood antioxidant status and inflammatory parameters resulted unaffected by Rhodiola Rosea supplementation. Blood lactate and plasma creatine kinase levels were found significantly lower (P<0.05) in Rhodiola Rosea treated subjects when compared to the placebo treated group. CONCLUSION: Chronic Rhodiola Rosea supplementation is able to reduce both lactate levels and parameters of skeletal muscle damage after an exhaustive exercise session. Moreover this supplementation seems to ameliorate fatty acid consumption. Taken together those observation confirm that Rhodiola Rosea may increase the adaptogen ability to physical exercise.
Assuntos
Antioxidantes , Suplementos Nutricionais , Extratos Vegetais/uso terapêutico , Espécies Reativas de Oxigênio , Rhodiola , Adulto , Análise de Variância , Creatina Quinase/sangue , Exercício Físico , Teste de Esforço , Ácidos Graxos não Esterificados , Indicadores Básicos de Saúde , Humanos , Ácido Láctico/sangue , Masculino , Músculo Esquelético/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Fitoterapia , Fatores de Tempo , Adulto JovemRESUMO
Formation of adducts between the antitumor ruthenium(III) complex [HInd]trans-[RuCl(4)(Ind)(2)] (KP1019) and the plasma proteins serum albumin and serum transferrin was investigated by UV-vis spectroscopy, for metal-to-protein ratios ranging from 1:1 to 5:1. In both cases, formation of tight metal-protein conjugates was observed. Similar spectroscopic features were observed for both albumin and transferrin derivatives implying a similar binding mode of the ruthenium species to these proteins. Surface histidines are the probable anchoring sites for the bound ruthenium(III) ions in line with previous crystallographic results. In order to assess the stability of the KP1019-protein adducts the influence of pH, reducing agents and chelators was analysed by UV-vis spectroscopy. Notably, there was no effect of addition of EDTA on the UV-vis spectra of the conjugates. The pH-stability was high in the pH range 5-8. Experiments with sodium ascorbate showed that there was just some alteration of selected bands. The implications of the present results are discussed in relation to the pharmacological behavior of this novel class of antitumor compounds.
Assuntos
Antineoplásicos/química , Dimetil Sulfóxido/análogos & derivados , Dimetil Sulfóxido/química , Compostos Organometálicos/química , Soroalbumina Bovina/química , Transferrina/química , Animais , Antineoplásicos/metabolismo , Bovinos , Dimetil Sulfóxido/metabolismo , Compostos Organometálicos/metabolismo , Ligação Proteica , Compostos de Rutênio , Soroalbumina Bovina/metabolismoRESUMO
Renal cortical brush-border (BBM), basolateral membrane (BLM), and medullary plasma membrane (mPM) preparations were analyzed to assess the effects of life-long food restriction in aged rats on membrane lipid content. Young male Fischer 344 x Brown-Norway F1 rats consumed food ad libitum (young AL) or were food-restricted (FR, 60% of AL consumption) for either 6 weeks (young FR) or until the age of 30 months old (old FR). Senescent FR rats had 50 per cent decreases in fractional excretion of Na and K (p < 0.001) as compared with the young AL rats. Long-term FR reduced phosphate and titratable acid excretion by 80 per cent (p < 0.001). These values were not significantly different from those observed in young rats during 6 weeks of FR. Food restriction decreased renal Na, K-ATPase activity by 50 per cent (p < 0.001) in both old and young FR animals. Reduction of food intake, in old and young rats, decreased all BBM phospholipid concentrations (phosphatidylserine, phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin) by 50 per cent than in the AL rats (p < 0.001). In BLM, chronic FR resulted only in lower phosphatidylcholine concentration (by 21%, p < 0.05) while phosphatidylethanolamine was increased approximately 80 per cent (p < 0.001). Total phospholipid content in mPM was progressively decreased by 23 per cent (p < 0.05) in the young FR group to be 55 per cent (p < 0.001) in the old FR rats. Cholesterol content was reduced in BBM and mPM by 38 per cent and 25 per cent (p < 0.05), respectively, during long-term FR. Both total phospholipid and cholesterol contents detected in mPM of the old FR rats were significantly lower than those obtained from the young FR animals (by 42%, p < 0.001 and 12%, p < 0.05, respectively). Plasma glucose, blood urea nitrogen, and body weight maintained at significantly lower levels during chronic FR. That life-long FR could prevent renal membrane lipid deposition and could lower renal work may explain the mechanisms that FR can delay the onset and diminish the severity of age-associated renal diseases.
Assuntos
Envelhecimento/fisiologia , Privação de Alimentos , Córtex Renal/metabolismo , Fosfolipídeos/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Membrana Basal/metabolismo , Transporte Biológico/fisiologia , Dieta , Córtex Renal/fisiologia , Nefropatias/prevenção & controle , Testes de Função Renal , Metabolismo dos Lipídeos , Masculino , Microvilosidades , Modelos Animais , Fosfolipídeos/análise , Ratos , Ratos Endogâmicos F344 , Valores de Referência , ATPase Trocadora de Sódio-Potássio/análise , Fatores de TempoRESUMO
Ferrimyoglobin at pH 7.4 binds nitric oxide to yield nitric oxide adducts. In the presence of glutathione (GSH), nitrosoadducts of Mb(III) react with it to give nitrosoglutathione, whose concentration has been determined with an apparatus based on a specific and sensitive solid-state amperometric gas sensor. The reaction constant between the adduct and glutathione, kGSH = (47 +/- 1) M(-1) x s(-1), obtained by UV-Vis spectroscopy kinetic measurements, is about one-eighth of the constant with OH- determined by other authors. We can explain this fact with the higher nucleophilicity of OH- compared to GSH, due to the bulkiness and charge of the species. It is known that the formation of nitrosothiols starting from nitrite or NO (nitrogen monoxide) and glutathione, in the absence of oxygen, is impossible. Thus, from a biological point of view, it is important to point out that GSH reacts with NO in the presence of ferrimyoglobin, even at physiological pH, to form nitrosoglutathione.
Assuntos
Glutationa/química , Metamioglobina/química , Ácido Nítrico/química , Glutationa/metabolismo , Cinética , Metamioglobina/metabolismo , Ácido Nítrico/metabolismoRESUMO
We investigated the ability of different hydroperoxides generated by lipoxygenase isozymes to induce programmed cell death (PCD) in human cells. Erythroleukemia K562 and neuroblastoma CHP100 cells were used, because they showed high basal activity of lipoxygenase. The hydroperoxides generated by 5-, 12-, or 15-lipoxygenases from linoleate, linolenate, or arachidonate, and the corresponding hydroxides, were able to induce PCD in both cell types, in a concentration- and time-dependent manner. After 24 h, K562 and CHP100 cells showed 2.5- to 3.5-fold more apoptotic bodies than the untreated controls. PCD elicited by lipoxygenase products was independent of intracellular glutathione concentration, and did not require mRNA transcription or protein synthesis. On the other hand, lipoxygenase products evoked an immediate and sustained rise in cytoplasmic calcium (within seconds), followed by mitochondrial uncoupling (within hours). Unlike the hydro(pero)xides, the terminal products of the arachidonate cascade (i.e., leukotrienes, prostaglandins and thromboxane) were not cytotoxic.
Assuntos
Apoptose , Leucemia Eritroblástica Aguda/enzimologia , Leucemia Eritroblástica Aguda/patologia , Lipoxigenase/metabolismo , Neuroblastoma/enzimologia , Neuroblastoma/patologia , Apoptose/efeitos dos fármacos , Ácido Araquidônico/metabolismo , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Glutationa/antagonistas & inibidores , Glutationa/metabolismo , Humanos , Isoenzimas/metabolismo , Células K562 , Leucotrienos/farmacologia , Ácido Linoleico/metabolismo , Peróxidos Lipídicos/metabolismo , Peróxidos Lipídicos/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Prostaglandinas/farmacologia , Tromboxano B2/farmacologia , Fatores de Tempo , Células Tumorais Cultivadas , Desacopladores/metabolismo , Desacopladores/farmacologia , Ácido alfa-Linolênico/metabolismoRESUMO
Several inducers of cytotoxic stress promote apoptotic cell death, which, at least in some cases, involves the CD95/CD95 ligand (CD95L) pathway. The induction of the CD95/CD95L pathway can be activated by the activator protein-1 (AP-1)-mediated up-regulation of the CD95L promoter, which is responsible for the induction of apoptosis elicited by stimuli such as etoposide. We show that nitric oxide (NO) represents a regulatory element able to block apoptosis by interfering with this loop. Etoposide- and C6-ceramide-induced apoptosis in Jurkat T cells with different kinetics. Cell death was accompanied by an increase in DNA-binding activity of the transcription factor AP-1, transactivation of the AP-1 site-containing CD95L promoter, and caspase 3-like protease activation. Using different NO-releasing compounds, we found that apoptosis was prevented in a dose-dependent manner. Furthermore, in both models of apoptosis, NO-releasing compounds dose-dependently reduced: (a) the number of the titratable thiol groups (cysteine residues) of c-Jun; (b) induction of AP-1 DNA-binding activity; (c) AP-1-driven transactivation of the CD95L promoter; and (d) caspase activation. In conclusion, our data demonstrate that NO can modulate cell death at an upstream level, by interfering with the ability of AP-1 to induce CD95L expression.
Assuntos
Apoptose , Glicoproteínas de Membrana/metabolismo , Óxido Nítrico/farmacologia , Fator de Transcrição AP-1/metabolismo , Ativação Transcricional , Sequência de Aminoácidos , Western Blotting , Núcleo Celular/metabolismo , Ceramidas/farmacologia , Fragmentação do DNA , Relação Dose-Resposta a Droga , Etoposídeo/farmacologia , Proteína Ligante Fas , Humanos , Células Jurkat , Modelos Biológicos , Dados de Sequência Molecular , Doadores de Óxido Nítrico/farmacologia , Inibidores da Síntese de Ácido Nucleico/farmacologia , Penicilamina/análogos & derivados , Penicilamina/farmacologia , Poli(ADP-Ribose) Polimerases/farmacologia , Proteínas Proto-Oncogênicas c-jun/metabolismo , Fatores de Tempo , TransfecçãoRESUMO
BACKGROUND: Potassium depletion is a common electrolyte abnormality in elderly humans, usually as a consequence of diuretic use or poor oral intake. Hypokalemia is associated with a number of changes in renal function and an increase in some renal membrane transporters; its growth-promoting effect in young animals is well known. With aging, the renal adaptation to a number of challenges is often diminished. We hypothesized that aging is related to decreases in renal function, renal membrane protein metabolism, as well as Na, K-ATPase protein abundance and activity in both control animals as well as in those with potassium depletion. OBJECTIVE: We examined the effects of dietary-induced hypokalemia in true-aged nonobese rats (30 months old) on renal function, cortical brush border membrane (BBM) and basolateral membrane (BLM) protein metabolism, and Na,K-ATPase protein abundance and activity. We compared the results obtained to those seen in their 4-month-old counterparts similarly treated. METHODS: Young (4-month-old) and senescent (30-month-old) male Fisher 344 x Brown-Norway F(1) rats (F344 x BNF(1)) were fed either a normal or potassium-deficient diet for 7 days. At 24 h, the U-(14)C-leucine incorporation was measured for determination of protein metabolism in renal BBM and BLM. Cortical BLM vesicle and microdissected proximal convoluted tubule (PCT) Na, K-ATPase activities were determined along with Western blot analysis of the cortical BLM alpha(1) subunit of Na,K-ATPase. Metabolic and renal function parameters were also examined. RESULTS: Hypokalemia caused hyperbicarbonatemia, hyperglycemia, and azotemia, but only in the senescent animals. The aged control rats had a higher basal level of urine volume, ammonium excretion, and fractional excretion of chloride. By contrast, aging in the F344 x BNF(1) rats was associated with a decrease in plasma aldosterone (by 35%) and phosphate (by 40%) levels as compared with their young controls. Hypokalemia resulted in a significant reduction of plasma aldosterone and a rise in muscle sodium concentration in both age groups; it significantly increased renal BBM and BLM protein concentrations in the young group, while these parameters remained unchanged in the senescent rats. The aged potassium-depleted animals showed a 14% decrease in BBM protein biosynthesis, but there were no changes in the young hypokalemic rats. Both potassium-depleted elderly and young rats had a significant reduction (by 33%) in BLM protein biosynthesis. Hypokalemia significantly increased the Na, K-ATPase activity in both cortical BLM vesicles and in microdissected PCT. The percentage increase in microdissected PCT segments (Na,K-ATPase activity) in elderly potassium-depleted animals was significantly less than that seen in hypokalemic young ones. Aging, per se, was associated with decreased basal microdissected PCT Na,K-ATPase activity in control animals. Hypokalemia had no effect on cortical BLM alpha(1) subunit Na, K-ATPase protein abundance in either age group. CONCLUSIONS: The present study provides the first evidence in nonobese aged rats as to the metabolic parameters, renal function, renal cortical membrane protein metabolism, and transporter Na,K-ATPase activity and abundance during potassium depletion. The aged nonobese F344 x BNF(1) rats responded differently from their young nonobese counterparts following potassium depletion. These differences may contribute substantially to the effects often encountered in elderly humans receiving diuretics or having a poor dietary potassium intake.
Assuntos
Envelhecimento , Hipopotassemia/fisiopatologia , Rim/fisiologia , Proteínas de Membrana/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Fatores Etários , Animais , Membrana Celular/enzimologia , Membrana Celular/metabolismo , Dieta , Eletroforese em Gel de Poliacrilamida , Hipopotassemia/sangue , Immunoblotting , Túbulos Renais Proximais/enzimologia , Masculino , Microvilosidades/metabolismo , Potássio/administração & dosagem , Potássio/sangue , Deficiência de Potássio/sangue , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344RESUMO
Food restriction (FR) exerts a variety of beneficial effects and may prolong life in both humans and animals. However, studies of its effects on the cortical brush border membrane (BBM) and basolateral membrane (BLM) lipid concentration, which may be pertinent to renal function, have not been reported in detail. We hypothesized that FR would decrease renal work and lower renal membrane lipid concentration. The changes in lipid concentration would be most dramatic in BBM because this membrane is the entry site for the recovery of filtered ions and nutrients. Young male Fischer 344 x Brown-Norway F1 rats consumed food ad libitum (AL) or were food-restricted (FR, 60% of AL consumption) for 6 wk. AL rats had higher fractional excretions of Na(+), K(+), and Cl(-) than did the FR group (P < 0.001). Renal Na,K-ATPase activity in AL rats was 100% higher than in FR rats (P < 0.001), reflecting greater renal work. The work required for renal proton secretion was lower in FR than in the AL rats. In FR rats, all BBM phospholipid concentrations (phosphatidylserine, phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin) were approximately 50% lower than in the AL rats (P < 0.001). In the BLM, food restriction resulted only in lower phosphatidylcholine concentration, while the other phospholipids were unaffected. Plasma and renal membrane (BBM and BLM) cholesterol concentrations were significantly lower in FR than in AL rats. These results show that a nutritionally complete, but energy restricted, diet improves renal function. It also prevents renal membrane lipid deposition and decreases plasma cholesterol. Prolonged food restriction might attenuate the renal injury that occurs in obese humans as a consequence of insulin resistance and atherosclerosis.
Assuntos
Privação de Alimentos , Córtex Renal/metabolismo , Metabolismo dos Lipídeos , Animais , Membrana Basal/metabolismo , Transporte Biológico , Córtex Renal/química , Masculino , Microvilosidades/metabolismo , Fosfolipídeos/análise , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344 , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
OBJECTIVE: To determine the qualitative and quantitative expression of alpha and gamma sodium pump subunits in whole kidney and nephron segment RNA from Sprague Dawley rats, spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. DESIGN: A novel reverse transcription polymerase chain reaction technique was devised which provides accurate and precise measurement of the number of molecules of specific transcript abundance, a measurement of gene expression. This allows the quantitative comparison of multiple samples across multiple subjects and, since the estimates are accurate rather than relative, can also be used to make quantitative comparisons across expressed genes, such as isoforms and subunits of the heterotrimeric renal sodium pump. METHODS: We examined which catalytic isoforms were expressed and then quantified transcript abundance in whole kidney and convoluted and straight segments of the proximal tubule. RESULTS: Alpha 1 and gamma transcripts, but not alpha 2, alpha 3 or alpha 4 isoforms, were consistently observed in nephron segments. Levels of alpha 1 were lower in kidney RNA from 15-16-week-old SHR than in WKY rats of the same age (P = 0.001), but were not different between SHR and WKY in 4-5-week-old animals. No significant difference was observed in gamma subunit abundance in kidney RNA from 4-5-week-old animals; however, at 15-16 weeks, the expression in SHR was one-third that in WKY rats (P = 0.003). In proximal convoluted tubules from 4-5-week-old animals, the level of alpha 1 RNA expression was lower (P = 0.03) in SHR than in WKY rats. In addition, levels of alpha 1 in proximal straight tubule from the 4-5-week-old SHR were also lower than in WKY rats (P = 0.02). This difference was even greater in 15-16-week-old animals: in SHR, alpha 1 expression was less than 20% of the level of expression in WKY rats (P = 0.0003). Expression of the gamma subunit exhibited a similar pattern of downregulation in SHR. In RNA from proximal convoluted tubules and proximal straight tubules from both 4-5- and 15-16-week-old animals, expression of the gamma subunit was demonstrated to be significantly lower in SHR than in WKY rats. CONCLUSION: The results indicate a coordinate reduction in the abundance of sodium pump alpha and gamma subunits in the proximal tubules of SHR, which occurs early during the development of hypertension.
Assuntos
Hipertensão/metabolismo , Néfrons/metabolismo , ATPase Trocadora de Sódio-Potássio/biossíntese , Animais , Expressão Gênica , Hipertensão/genética , Rim/metabolismo , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/genética , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , ATPase Trocadora de Sódio-Potássio/genéticaRESUMO
The bacterial topoisomerase II (DNA gyrase) and the mammalian topoisomerase II represent the cellular targets for quinolone antibacterials and a wide variety of anticancer drugs, respectively. In view of the mechanistic similarities and sequence homologies exhibited by the two enzymes, tentative efforts to selectively shift from an antibacterial to an antitumoral activity was made by synthesizing a series of modified tricyclic quinolones, in which the essential 3-carboxylic function is surrogated by phenolic OH and the classic C-6 fluorine atom is replaced by a NH2 group. The resulting 7-amino-9-acridone derivatives were assayed for their antibacterial as well as cytotoxic activities. No antibacterial activity was found. On the other hand, many derivatives showed significant cytotoxic activity against both HL-60 and P388 leukemias and a wide panel of human and rodent solid tumor cells, derivatives 25 and 26 displaying the best overall antiproliferative activity. Against the LoVo cell line, derivative 25 exhibited higher cytotoxic effects than etoposide.
Assuntos
Acridinas/síntese química , Antineoplásicos/síntese química , Quinolonas/síntese química , Acridinas/química , Acridinas/farmacologia , Animais , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Cricetinae , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Camundongos , Quinolonas/química , Quinolonas/farmacologia , Relação Estrutura-Atividade , Inibidores da Topoisomerase II , Células Tumorais CultivadasRESUMO
The renal tubular acidosis syndromes are nonuremic defects of urinary acidification. They are characterized by a normal anion gap and hyperchloremic metabolic acidosis; plasma potassium may be normal, low, or high, depending on the syndrome present. As new technologies have been applied to biology, we now better understand the basic lesions of these important syndromes.
Assuntos
Acidose Tubular Renal , Acidose Tubular Renal/fisiopatologia , Animais , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Humanos , Túbulos Renais Distais/fisiopatologia , Potássio/sangue , Bombas de Próton/metabolismo , ATPases Translocadoras de Prótons/metabolismoRESUMO
Management of end-stage renal disease (ESRD) has been revolutionized by the advent of erythropoietin replacement. We briefly review its characteristics and clinical use. Also emphasized is the importance of iron deficiency in limiting the clinical response to erythropoietin therapy. Iron-replacement therapy in ESRD patients is briefly discussed.
Assuntos
Anemia/etiologia , Doenças Cardiovasculares/etiologia , Eritropoetina/efeitos adversos , Ferro/uso terapêutico , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Anemia/tratamento farmacológico , Eritropoetina/uso terapêutico , Humanos , Hipertensão/etiologiaRESUMO
The mechanism by which increased dietary intake of calcium reduces blood pressure in the spontaneously hypertensive rat is unknown. The present studies were designed to determine if there were alterations in the activity of the major membrane ion translocating pump, sodium, potassium-ATPase (NKA), in the kidneys of hypertensive rats and whether increased dietary calcium intake affected the activity of this enzyme. Fifteen-week old SHR's were found to have lower total ATPase activity in microsomal preparations from the kidney than age matched Wistar-Kyoto animals. Both the ouabain-sensitive component (NKA) and the ouabain-insensitive component were lower in SHR. Increasing dietary calcium intake from 1% to 3% elevated both components of the ATPase activity in SHR, but was without effect in WKY. Measurement of membrane phospholipid composition suggested that altered phospholipid composition did not account for the reduced ATPase activity observed, but indicated a reduced density of ATPase in SHR. A technique has been devised for qualitative and quantitative analysis of Na, K-ATPase alpha isoforms using RT-PCR. This technique reveals that the alpha 1 isoform is the sole catalytic isoform present in the nephron. Accurate and precise quantification of the amount of gene expression in individual nephron segments is reported and will be applied to determine whether dietary calcium influences blood pressure by a mechanism which alters nephron NKA gene expression.
Assuntos
Expressão Gênica , Hipertensão/enzimologia , Rim/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Pressão Sanguínea , Cálcio da Dieta/farmacologia , Primers do DNA/química , Rim/citologia , Rim/efeitos dos fármacos , Masculino , Microssomos/enzimologia , Fosfolipídeos/metabolismo , Reação em Cadeia da Polimerase , RNA/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , ATPase Trocadora de Sódio-Potássio/genéticaRESUMO
These experiments were designed to examine the effects of A-23187 (5 x 10(-4) M) and verapamil (100 microM) on membrane transport, 45Ca fluxes, and adenosine-triphosphatase (ATPase) activities in turtle bladder. In the intact membrane, the calcium ionophore decreased proton secretion and sodium transport [short-circuit current (SCC)] to approximately the same degree (by approximately 55% at 30 min). During the same period of time, verapamil decreased SCC (by approximately 58%), but proton secretion was unaffected. The turtle bladder membrane is composed predominantly of two cell types: 1) the mitochondrial-rich cells (MR cells) thought to be involved in proton (and bicarbonate) secretion containing significant H(+)-ATPase and Ca(2+)-ATPase and 2) the granular cells (G cells), postulated important in sodium reabsorption, having abundant Na(+)-K(+)-ATPase. That Na(+)-K(+)-ATPase activity was unchanged by either a calcium ionophore or a calcium channel blocker suggests that the decrease in SCC noted in the intact membrane is not directly mediated by changes in the sodium "pump." The decrease of H(+)-ATPase in MR cells, which resulted after the A-23187, suggests that it probably exerts a direct action on the proton pump, which decreases hydrogen ion secretion. The increase in ATP-dependent 45Ca transport seen after the ionophore (or the decrease in ATP-independent 45Ca transport after verapamil) most likely reflects increased (or decreased) Ca2+ availability within the cytosol, and the high (or low) cell calcium could decrease the SCC. These results thus suggest that cytosolic Ca2+ reciprocally sets, by different mechanisms, the rate of proton secretion in MR cells and the sodium reabsorption in G cells.