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1.
Urology ; 143: e5-e6, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32504686

RESUMO

We present the case of a male with a fistula from an infrarenal aortic aneurysm to the left renal vein resolved with an endovascular prosthesis. Few cases have been reported in the literature.


Assuntos
Aorta Abdominal , Aneurisma da Aorta Abdominal/complicações , Fístula Arteriovenosa/complicações , Veias Renais , Idoso , Humanos , Masculino
2.
J Physiol ; 593(8): 2071-84, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25656230

RESUMO

Clenbuterol is a ß2 -adrenergic receptor agonist known to induce skeletal muscle hypertrophy and a slow-to-fast phenotypic shift. The aim of the present study was to test the effects of chronic clenbuterol treatment on contractile efficiency and explore the underlying mechanisms, i.e. the muscle contractile machinery and calcium-handling ability. Forty-three 6-week-old male Wistar rats were randomly allocated to one of six groups that were treated with either subcutaneous equimolar doses of clenbuterol (4 mg kg(-1) day(-1) ) or saline solution for 9, 14 or 21 days. In addition to the muscle hypertrophy, although an 89% increase in absolute maximal tetanic force (Po ) was noted, specific maximal tetanic force (sPo) was unchanged or even depressed in the slow twitch muscle of the clenbuterol-treated rats (P < 0.05). The fit of muscle contraction and relaxation force kinetics indicated that clenbuterol treatment significantly reduced the rate constant of force development and the slow and fast rate constants of relaxation in extensor digitorum longus muscle (P < 0.05), and only the fast rate constant of relaxation in soleus muscle (P < 0.05). Myofibrillar ATPase activity increased in both relaxed and activated conditions in soleus (P < 0.001), suggesting that the depressed specific tension was not due to the myosin head alteration itself. Moreover, action potential-elicited Ca(2+) transients in flexor digitorum brevis fibres (fast twitch fibres) from clenbuterol-treated animals demonstrated decreased amplitude after 14 days (-19%, P < 0.01) and 21 days (-25%, P < 0.01). In conclusion, we showed that chronic clenbuterol treatment reduces contractile efficiency, with altered contraction and relaxation kinetics, but without directly altering the contractile machinery. Lower Ca(2+) release during contraction could partially explain these deleterious effects.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Clembuterol/farmacologia , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Adenosina Trifosfatases/metabolismo , Animais , Cálcio/metabolismo , Hipertrofia/induzido quimicamente , Hipertrofia/metabolismo , Masculino , Músculo Esquelético/metabolismo , Doenças Musculares/induzido quimicamente , Doenças Musculares/metabolismo , Ratos , Ratos Wistar
4.
Cir Pediatr ; 23(3): 141-3, 2010 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-23155658

RESUMO

OBJECTIVE: Analyze the results of the living related donor kidney transplant (LRDKT) in our center. PATIENTS AND METHODS: Between December 2005 and 2008, 34 kidney transplants in pediatric recipients were performed in our center, 7 (20.58%) of which were LRDKT with grafts obtained via laparoscopy. The donor was the mother in 4 cases and the father in 3. Mean age of the donors was 43 years (38-48) and of the recipients 12.5 years (9-17). Four were a first transplant (one of them planned) and three retransplantations. RESULTS: Cold ischemia time was < 2 hours in every case while warm ischemia did not show significant differences with the cadaveric donor transplant. None had initial graft dysfunction. No vascular complications occurred, but there was a urinary fistula secondary to ureteral necrosis, resolved with a new reimplantation. Survival of the patient and graft is 100%, superior to that of the cadaveric grafts within the same period. Current mean plasma creatinine is 0.8 mg/dl (0.7-1.39) and mean creatinine clearance is 80 cc/min/1.73 m2 (75-90). No donor had surgical complication and all maintain good kidney function. CONCLUSIONS: The short term results of the LRDKT with grafts obtained by laparoscopy in our center are similar to those described by groups with large experience, which makes it possible to continue offering it with guarantee.


Assuntos
Transplante de Rim , Laparoscopia , Doadores Vivos , Nefrectomia/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Cir Pediatr ; 21(3): 135-7, 2008 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-18756865

RESUMO

AIM: To show our experience in urinary derivation by ureteral meatotomy associated with vesicostomy. METHODS: We reviewed uni or bilateral ureteral meatotomy associated with vesicostomy carried out in our institution between 1989 and 2006. We report 20 patients (15 boys and 5 girls) with ages ranging from 1 month to 13-years-old (median 4,4-years-olds). Nine (45%) had neuropathic bladder, 6 (30%) posterior urethral valves and 5 (25%) vesicoureteral stenosis. RESULTS: Improvement of the ureteral dilatation controlled by ultrasound was demonstrated in 100% of the patients. Improvement of the renal function was observed in the group of patients (5) with renal failure. COMPLICATIONS: 2 bladder prolapses, 1 calculus and 1 postoperative bladder bleeding. CONCLUSIONS: Ureteral meatotomy associated with vesicostomy is an effective urinary derivation in children with obstructive urological conditions with an important dilatation in which ureteral reimplantation seems to be difficult. This derivation avoids bladder dysfunction and the management of the vesicostomy is comfortable by the use of a bag or the nappies.


Assuntos
Cistostomia , Obstrução Ureteral/cirurgia , Uretra/anormalidades , Uretra/cirurgia , Bexiga Urinaria Neurogênica/cirurgia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Derivação Urinária/métodos
8.
Cir Pediatr ; 21(2): 89-91, 2008 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-18624276

RESUMO

AIM: To show our experience with biofeedback and electrostimulation techniques in the treatment of non monosymptomatic enuresis. METHODS: We reviewed biofeedback and electrostimulation techniques in the treatment of complicated enuresis carried out in our institution between 1995 and 2000. We report 99 patients (65 girls and 34 boys) with ages ranging from 5 to 14 years old. A complete urodinamy study divided the patients into 5 groups: detrusor-sphincter dysfunction (DSD) (47 patients), detrusor overactivity (DO) (25 patients), urge syndrome (US) (15 patients), sphincter hypertony (SH) (10 patients) and "retentionist" bladder (RB) (2 patients). Success was defined as less than three wet nights in a month. Biofeedback and electrostimulation program was designed in 10 sessions per week (20 minutes each session) with SIGMAX-Biomedical software. Tibial electrostimulation with SANS-UroSurge equipment was indicated when biofeedback and electrostimulation techniques failed (12 sessions per week, 30 minutes each session). RESULTS. The success rate has been 78.9% in DSD group, 80% in DO group, 85% in US group, 75% in SH group, 100% in RB group. CONCLUSIONS: Effectiveness of biofeedback and electrostimulation techniques in the treatment of non monosymptomatic enuresis has been reported and seems to be permanent in time.


Assuntos
Biorretroalimentação Psicológica , Terapia por Estimulação Elétrica , Enurese/terapia , Adolescente , Criança , Pré-Escolar , Enurese/diagnóstico , Feminino , Humanos , Masculino , Estudos Retrospectivos
9.
Am J Physiol Regul Integr Comp Physiol ; 294(6): R1911-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18417650

RESUMO

This study aimed to determine the changes in soleus myofibrillar ATPase (m-ATPase) activity and myosin heavy chain (MHC) isoform expression after endurance training and/or chronic hypoxic exposure. Dark Agouti rats were randomly divided into four groups: control, normoxic sedentary (N; n = 14), normoxic endurance trained (NT; n = 14), hypoxic sedentary (H; n = 10), and hypoxic endurance trained (HT; n = 14). Rats lived and trained in normoxia at 760 mmHg (N and NT) or hypobaric hypoxia at 550 mmHg (approximately 2,800 m) (H and HT). m-ATPase activity was measured by rapid flow quench technique; myosin subunits were analyzed with mono- and two-dimensional gel electrophoresis. Endurance training significantly increased m-ATPase (P < 0.01), although an increase in MHC-I content occurred (P < 0.01). In spite of slow-to-fast transitions in MHC isoform distribution in chronic hypoxia (P < 0.05) no increase in m-ATPase was observed. The rate constants of m-ATPase were 0.0350 +/- 0.0023 s(-1) and 0.047 +/- 0.0050 s(-1) for N and NT and 0.033 +/- 0.0021 s(-1) and 0.038 +/- 0.0032 s(-1) for H and HT. Thus, dissociation between variations in m-ATPase and changes in MHC isoform expression was observed. Changes in fraction of active myosin heads, in myosin light chain isoform (MLC) distribution or in MLC phosphorylation, could not explain the variations in m-ATPase. Myosin posttranslational modifications or changes in other myofibrillar proteins may therefore be responsible for the observed variations in m-ATPase activity.


Assuntos
Adenosina Trifosfatases/metabolismo , Hipóxia/fisiopatologia , Músculo Esquelético/enzimologia , Miofibrilas/enzimologia , Condicionamento Físico Animal/fisiologia , Resistência Física/fisiologia , Animais , Peso Corporal/fisiologia , Cálcio/metabolismo , Masculino , Cadeias Pesadas de Miosina/metabolismo , Ratos , Ratos Endogâmicos
10.
Acta Physiol (Oxf) ; 193(2): 163-73, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18081885

RESUMO

AIM: To determine whether endurance training can counterbalance the negative effects of hypoxia on mitochondrial phosphorylation and expression of the long chain mitochondrial fatty acid transporter muscle carnitine palmitoyl transferase 1 (mCPT-1). METHODS: Male Wistar rats were exposed either to hypobaric hypoxia (at a simulated altitude of approximately 4000 m, PIO(2) approximately 90 mmHg) or to normoxia (sea level) for 5 weeks. In each environment, rats were randomly assigned to two groups. The trained group went through a 5-week endurance training programme. The control group remained sedentary for the same time period. Muscle fatty acid oxidation capacity was evaluated after the 5-week period on isolated mitochondria prepared from quadriceps muscles with the use of palmitoylcarnitine or pamitoylCoA + carnitine. RESULTS: Chronic hypoxia decreased basal (V(0), -31% with pamitoylCoA + carnitine and -21% with palmitoylcarnitine, P < 0.05) and maximal (V(max), -31% with pamitoylCoA + carnitine, P < 0.05) respiration rates, hydroxyacylCoA dehydrogenase activity (-48%, P < 0.05), mCPT-1 activity index (-34%, P < 0.05) and mCPT-1 protein content (-34%, P < 0.05). Five weeks of endurance training in hypoxia brought V(0), mCPT-1 activity index and mCPT-1 protein content values back to sedentary normoxic levels. Moreover, in the group trained in hypoxia, V(max) reached a higher level than in the group that maintained a sedentary lifestyle in normoxia (24.2 nmol O(2). min(-1) . mg(-1) for hypoxic training vs. 19.9 nmol O(2) . min(-1) . mg(-1) for normoxic sedentarity, P < 0.05). CONCLUSION: Endurance training can attenuate chronic hypoxia-induced impairments in mitochondrial fatty acid oxidation. This training effect seems mostly mediated by mCPT-1 activity rather than by mCPT-1 content.


Assuntos
Hipóxia/metabolismo , Metabolismo dos Lipídeos , Músculo Esquelético/metabolismo , Condicionamento Físico Animal/fisiologia , 3-Hidroxiacil-CoA Desidrogenases/metabolismo , Altitude , Animais , Peso Corporal , Carnitina O-Palmitoiltransferase/metabolismo , Respiração Celular , Doença Crônica , Citrato (si)-Sintase/metabolismo , Ácidos Graxos/metabolismo , Hemoglobinas/metabolismo , Masculino , Mitocôndrias Musculares/metabolismo , Oxirredução , Condicionamento Físico Animal/métodos , Ratos , Ratos Wistar
11.
Cir Pediatr ; 20(2): 133-5, 2007 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-17650728

RESUMO

We report a new case of congenital lumbar hernia. This is first case reported of congenital lumbar hernia and bilateral renal agenesis. We review literature and describe associated malformations reported that would be role out in every case of congenital lumbar hernia.


Assuntos
Anormalidades Múltiplas , Hérnia/congênito , Hérnia/complicações , Rim/anormalidades , Evolução Fatal , Humanos , Recém-Nascido , Região Lombossacral , Masculino
12.
Actas Urol Esp ; 29(6): 596-8, 2005 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-16092685

RESUMO

Xanthogranulomatous pyelonephritis is an uncommon chronic inflammatory renal disorder. Most cases have been described in middle aged women and it is extremely rare in children. We report a case of a 4 year old girl who suffered from recurrent urinary tract infection and antibiotic therapy resistance. She had low growth-rate and palpable left renal mass on examination and was confirmed by radiological findings. We performed left kidney partial resection and then histological examination showed focal xanthogranulomatous pyelonephritis. The focal form of the disease may respond to antibiotic treatment although usually an enucleation or partial resection must be performed. In conclusion xanthogranulomatous pyelonephritis should be considered in the differential diagnosis of a renal mass and recurrent urinary tract infection in childhood.


Assuntos
Pielonefrite Xantogranulomatosa/diagnóstico , Pré-Escolar , Feminino , Humanos , Pielonefrite Xantogranulomatosa/cirurgia
13.
Am J Physiol Regul Integr Comp Physiol ; 289(6): R1618-24, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16081875

RESUMO

Humoral factors play an important role in the control of exercise hyperpnea. The role of neuromechanical ventilatory factors, however, is still being investigated. We tested the hypothesis that the afferents of the thoracopulmonary system, and consequently of the neuromechanical ventilatory loop, have an influence on the kinetics of oxygen consumption (VO2), carbon dioxide output (VCO2), and ventilation (VE) during moderate intensity exercise. We did this by comparing the ventilatory time constants (tau) of exercise with and without an inspiratory load. Fourteen healthy, trained men (age 22.6 +/- 3.2 yr) performed a continuous incremental cycle exercise test to determine maximal oxygen uptake (VO2max = 55.2 +/- 5.8 ml x min(-1) x kg(-1)). On another day, after unloaded warm-up they performed randomized constant-load tests at 40% of their VO2max for 8 min, one with and the other without an inspiratory threshold load of 15 cmH2O. Ventilatory variables were obtained breath by breath. Phase 2 ventilatory kinetics (VO2, VCO2, and VE) could be described in all cases by a monoexponential function. The bootstrap method revealed small coefficients of variation for the model parameters, indicating an accurate determination for all parameters. Paired Student's t-tests showed that the addition of the inspiratory resistance significantly increased the tau during phase 2 of VO2 (43.1 +/- 8.6 vs. 60.9 +/- 14.1 s; P < 0.001), VCO2 (60.3 +/- 17.6 vs. 84.5 +/- 18.1 s; P < 0.001) and VE (59.4 +/- 16.1 vs. 85.9 +/- 17.1 s; P < 0.001). The average rise in tau was 41.3% for VO2, 40.1% for VCO2, and 44.6% for VE. The tau changes indicated that neuromechanical ventilatory factors play a role in the ventilatory response to moderate exercise.


Assuntos
Limiar Diferencial/fisiologia , Inalação/fisiologia , Resistência Física/fisiologia , Esforço Físico/fisiologia , Ventilação Pulmonar/fisiologia , Adulto , Teste de Esforço , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Testes de Função Respiratória/métodos
14.
Int J Sports Med ; 26(6): 492-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16037894

RESUMO

This study investigated the effects of 40-week training on anxiety and perceived fatigue in four elite triathletes. Anxiety and perceived fatigue were self-reported by the subjects twice a week by the way of a specific questionnaire and were linked by a mathematical model to the training loads calculated from the exercise heart rate. A significant relationship (r=0.32; p<0.001) between the training loads and anxiety was identified using a two-component model: a first, negative (i.e., anxiety decreased) short-term (tau (1)=23 days) function and a second, positive long-term (tau (2)=59 days) function. The relationship between the training loads and perceived fatigue was significant (r=0.30; p<0.001), with one negative function (tau (1)=4 days). This mathematical model can potentially describe the relationships between training loads and anxiety or perceived fatigue and may improve both the adjustment of the duration of tapering and the early detection of staleness.


Assuntos
Ansiedade/psicologia , Fadiga/psicologia , Modelos Psicológicos , Esportes/psicologia , Carga de Trabalho/psicologia , Adulto , Comportamento Competitivo , Feminino , Humanos , Masculino , Educação Física e Treinamento/métodos , Resistência Física
15.
Int J Sports Med ; 26(5): 356-62, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15895318

RESUMO

This study examined the influence of moderate hypoxia on the oxygen uptake (V.O(2)) kinetic response (primary time constant and slow component amplitude) during moderate and heavy cycle exercise in twenty-seven male subjects with various training status. Nine endurance trained (21.5 +/- 2.6 yr), nine sprint trained (22.9 +/- 5.7 yr), and nine untrained controls (24.0 +/- 4.4 yr) completed incremental tests to exhaustion in normoxia (inspired gas concentration or FIO (2) = 21 % O(2)) and hypoxia (FIO (2) = 13 % O(2)) to establish the FIO (2)-specific ventilatory threshold (VT) and maximal VO(2). Subsequently, the subjects performed repeated constant work rate cycling exercises during 7 min at moderate intensity (80 % of FIO (2)-specific VT) and heavy intensity (midway between the FIO (2) specific VT and maximal VO(2)). Pulmonary gas exchange was measured breath-by-breath during all exercise sessions. For both moderate and heavy intensities, the time constant of the primary VO(2) component was significantly (p < 0.05) slowed by approximately 25 to 30 % in hypoxia compared to normoxia to the same extent in the three groups. Hypoxia produced a more important decrease in the amplitude of the slow component in endurance athletes (- 36 %) than in sprinters (- 30 %) and controls (- 12 %). These results suggest that both primary and slow components of VO(2) kinetics during the adjustment to moderate- and heavy-intensity exercise are sensitive to hypoxia while training status tended to modulate partly the slow component amplitude.


Assuntos
Exercício Físico/fisiologia , Hipóxia/fisiopatologia , Consumo de Oxigênio/fisiologia , Educação Física e Treinamento , Adulto , Estudos Transversais , Frequência Cardíaca/fisiologia , Humanos , Cinética , Masculino , Corrida/fisiologia
16.
Actas Urol Esp ; 28(2): 147-51, 2004 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-15074065

RESUMO

UNLABELLED: FUNDAMENTAL: [corrected] To show our initial experience in the TUR of prostate with bipolar axipolar bistoury. MATERIAL AND METHODS: Five patients with an average age of 72 years old, were operated between may and june 2002. They showed important increased in questionnaire symptoms (IPSS). The average ecographic volume has been 57.4 g. We employed Gyrus resector and physiological salt solution for continue irrigation. RESULTS: The average operative time was 70 minutes. None of the patients showed hyponatremia needed blood transfusion. In all the cases the sound was removed 48 hours after operation, one of them have urinary retention (UR) and need sound tow more days. Hospital stay was tree days except the patient how had UR. At 1 and 6 month there is improvement in the IPSS. CONCLUSIONS: TUR of prostate with bipolar axipolar bistoury can avoid the secondary effects of glicine and allows us to work with prostates of bigger volumes due to we have more time to do it. Nevertheless bigger and better studies are required to value the effectiveness of this new technology opposite the TUR of prostate with monopolar bistoury which keeps being the gold standard.


Assuntos
Hiperplasia Prostática/cirurgia , Ressecção Transuretral da Próstata/métodos , Idoso , Desenho de Equipamento , Humanos , Masculino , Ressecção Transuretral da Próstata/instrumentação
17.
Actas Urol Esp ; 28(1): 70-4, 2004 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-15046486

RESUMO

Adrenal metastases are more frequent than primary adrenal carcinoma. The most frequent are, in this order: breast and lung cancer, stomach and kidney carcinomas, adrenal gland contralateral tumors and melanoma. Less frequent are tumours of the bladder, colon, esophagus, gall bladder, liver, pancreas, prostate, stomach and uterus. The rest of the tumours rarely spread toward adrenal glands. The metastases to the adrenal glands caused by sarcomas are rare and normally they happen in the contest of a massive metastases affecting several organs at the same time. We present a case of a patient affected by adrenal metastases of Ewing's sarcoma who has been referred to us for surgical treatment because it is a unique metastases (there is no sing of more illnesses in other organs at the time of the exploration).


Assuntos
Neoplasias das Glândulas Suprarrenais/secundário , Neoplasias Ósseas/patologia , Ílio , Sarcoma de Ewing/secundário , Neoplasias das Glândulas Suprarrenais/diagnóstico , Humanos , Sarcoma de Ewing/diagnóstico
18.
J Sports Med Phys Fitness ; 43(3): 285-90, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14625508

RESUMO

AIM: The purpose of this study was to measure the effects of drafting on energy expenditure in in-line skating, and to investigate whether the "benefit of drafting", i.e. the decrease in energy expenditure, was different between two velocities and two distances separating the two skaters. METHODS: Eight recreational in-line skaters performed six exercises of 6 min, at 2 velocities (V(1) = 5.51+/-0.45 m x sec(-1); V(2) = 7.01+/-0.67 m x sec(-1)) in 3 conditions (ND = without drafting; D(1)=0.74-0.87 m "close"; D(2) = 1.19-1.36 m "far"). Collection of expired gas was carried out using a breath-by-breath portable gas analyser K4(b2) and the distance between the skaters was measured by video analysis. RESULTS: The skaters' energy expenditure was reduced in all drafting conditions; between D(1) and ND by 9.6+/-4.4% at V(1) and by 2.7+/-3.3% at V(2); between D(2) and ND by 8.8+/-6.0% at V(1) and by 4.2+/-4.8% at V(2). This reduction was significantly (p<0.05) more important at V(1) than V(2) and no differences were observed between D(1) and D(2). CONCLUSION: In in-line skating, the technical difficulties for drafting efficiently, especially while cornering, resulted in a reduced "benefit of drafting" at high velocity than in other sports. Moreover, the need for the subject to adjust their own cycle frequency to that of the lead skater while drafting "close" would explain partly that there were no significant differences between drafting at D(1) and D(2). These results suggest that the drafting technique should be emphasized in training, especially in non-skilled skaters at high velocities and when cornering.


Assuntos
Movimentos do Ar , Fenômenos Biomecânicos , Metabolismo Energético/fisiologia , Patinação/fisiologia , Adulto , Exercício Físico/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio/fisiologia , Valores de Referência
19.
Biophys J ; 85(5): 3132-41, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14581213

RESUMO

We obtained the temperature dependences of the adenosine triphosphatase (ATPase) activities (calcium-activated and relaxed) of myofibrils from a slow muscle, which we compared with those from a fast muscle. We chose rabbit soleus and psoas because their myosin heavy chains are almost pure: isoforms I and IIX, respectively. The Arrhenius plots of the ATPases are linear (4-35 degrees C) with energies of activation for soleus myofibrils 155 kJ mol(-1) (activated) and 78 kJ mol(-1) (relaxed). With psoas myofibrils, the energies of activation were 71 kJ mol(-1) (activated) and 60 kJ mol(-1) (relaxed). When extrapolated to 42 degrees C the ATPase rates of the two types of myofibril were identical: 50 s(-1) (activated) and 0.23 s(-1) (relaxed). Whereas with psoas myofibrils the K(m) for adenosine triphosphate (activated ATPase) is relatively insensitive to temperature, that for soleus myofibrils increased from 0.3 microM at 4 degrees C to 66.5 microM at 35 degrees C. Our results illustrate the importance of temperature when comparing the mechanochemical coupling in different types of muscle. We discuss the problem of how to reconcile the similarity of the myofibrillar ATPase rates at physiological temperatures with their different mechanical properties.


Assuntos
Adenosina Trifosfatases/metabolismo , Contração Muscular/fisiologia , Fibras Musculares de Contração Rápida/citologia , Fibras Musculares de Contração Rápida/fisiologia , Fibras Musculares de Contração Lenta/citologia , Fibras Musculares de Contração Lenta/fisiologia , Sarcômeros/fisiologia , Sarcômeros/ultraestrutura , Animais , Cálcio/metabolismo , Células Dendríticas , Ativação Enzimática , Estabilidade Enzimática , Membro Posterior/fisiologia , Cinética , Músculo Esquelético/citologia , Músculo Esquelético/fisiologia , Miofibrilas/fisiologia , Miofibrilas/ultraestrutura , Coelhos , Temperatura
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