TRAF2 Is a Novel Ubiquitin E3 Ligase for the Na,K-ATPase ß-Subunit That Drives Alveolar Epithelial Dysfunction in Hypercapnia.

Several acute and chronic lung diseases are associated with alveolar hypoventilation leading to accumulation of CO2 (hypercapnia). The ß-subunit of the Na,K-ATPase plays a pivotal role in maintaining epithelial integrity by functioning as a cell adhesion molecule and regulating cell surface stability of the catalytic α-subunit of the transporter, thereby, maintaining optimal alveolar fluid balance. Here, we identified the E3 ubiquitin ligase for the Na,K-ATPase ß-subunit, which promoted polyubiquitination, subsequent endocytosis and proteasomal degradation of the protein upon exposure of alveolar epithelial cells to elevated CO2 levels, thus impairing alveolar integrity. Ubiquitination of the Na,K-ATPase ß-subunit required lysine 5 and 7 and mutating these residues (but not other lysines) prevented trafficking of Na,K-ATPase from the plasma membrane and stabilized the protein upon hypercapnia. Furthermore, ubiquitination of the Na,K-ATPase ß-subunit was dependent on prior phosphorylation at serine 11 by protein kinase C (PKC)-ζ. Using a protein microarray, we identified the tumor necrosis factor receptor-associated factor 2 (TRAF2) as the E3 ligase driving ubiquitination of the Na,K-ATPase ß-subunit upon hypercapnia. Of note, prevention of Na,K-ATPase ß-subunit ubiquitination was necessary and sufficient to restore the formation of cell-cell junctions under hypercapnic conditions. These results suggest that a hypercapnic environment in the lung may lead to persistent epithelial dysfunction in affected patients. As such, the identification of the E3 ligase for the Na,K-ATPase may provide a novel therapeutic target, to be employed in patients with acute or chronic hypercapnic respiratory failure, aiming to restore alveolar epithelial integrity.

Guidelines for seizure management in palliative care: Proposal for an updated clinical practice model based on a systematic literature review. / Guía para el manejo de las crisis epilépticas en cuidados paliativos: propuesta de un modelo actualizado de práctica clínica basado en una revisión sistemática de la literatura.

INTRODUCTION: Very little has been written on seizure management in palliative care (PC). Given this situation, and considering the forthcoming setting up of the Palliative Care Unit at our neurorehabilitation centre, the Clínica San Vicente, we decided to establish a series of guidelines on the use of antiepileptic drugs (AEDs) for handling seizures in PC. METHODS: We conducted a literature search in PubMed to identify articles, recent manuals, and clinical practice guidelines on seizure management in PC published by the most relevant scientific societies. RESULTS: Clinical practice guidelines are essential to identify patients eligible for PC, manage seizures adequately, and avoid unnecessary distress to these patients and their families. Given the profile of these patients, we recommend choosing AEDs with a low interaction potential and which can be administered by the parenteral route, preferably intravenously. Diazepam and midazolam appear to be the most suitable AEDs during the acute phase whereas levetiracetam, valproic acid, and lacosamide are recommended for refractory cases and long-term treatment. CONCLUSIONS: These guidelines provide general recommendations that must be adapted to each particular clinical case. Nevertheless, we will require further well-designed randomised controlled clinical trials including large samples of patients eligible for PC to draft a consensus document recommending adequate, rational, and effective use of AEDs, based on a high level of evidence, in this highly complex area of medical care.

The small GTPases Ras and Rap1 bind to and control TORC2 activity.

Target of Rapamycin Complex 2 (TORC2) has conserved roles in regulating cytoskeleton dynamics and cell migration and has been linked to cancer metastasis. However, little is known about the mechanisms regulating TORC2 activity and function in any system. In Dictyostelium, TORC2 functions at the front of migrating cells downstream of the Ras protein RasC, controlling F-actin dynamics and cAMP production. Here, we report the identification of the small GTPase Rap1 as a conserved binding partner of the TORC2 component RIP3/SIN1, and that Rap1 positively regulates the RasC-mediated activation of TORC2 in Dictyostelium. Moreover, we show that active RasC binds to the catalytic domain of TOR, suggesting a mechanism of TORC2 activation that is similar to Rheb activation of TOR complex 1. Dual Ras/Rap1 regulation of TORC2 may allow for integration of Ras and Rap1 signaling pathways in directed cell migration.

The O-glycosylated ectodomain of FXYD5 impairs adhesion by disrupting cell-cell trans-dimerization of Na,K-ATPase ß1 subunits.

FXYD5 (also known as dysadherin), a regulatory subunit of the Na,K-ATPase, impairs intercellular adhesion by a poorly understood mechanism. Here, we determined whether FXYD5 disrupts the trans-dimerization of Na,K-ATPase molecules located in neighboring cells. Mutagenesis of the Na,K-ATPase ß1 subunit identified four conserved residues, including Y199, that are crucial for the intercellular Na,K-ATPase trans-dimerization and adhesion. Modulation of expression of FXYD5 or of the ß1 subunit with intact or mutated ß1-ß1 binding sites demonstrated that the anti-adhesive effect of FXYD5 depends on the presence of Y199 in the ß1 subunit. Immunodetection of the plasma membrane FXYD5 was prevented by the presence of O-glycans. Partial FXYD5 deglycosylation enabled antibody binding and showed that the protein level and the degree of O-glycosylation were greater in cancer than in normal cells. FXYD5-induced impairment of adhesion was abolished by both genetic and pharmacological inhibition of FXYD5 O-glycosylation. Therefore, the extracellular O-glycosylated domain of FXYD5 impairs adhesion by interfering with intercellular ß1-ß1 interactions, suggesting that the ratio between FXYD5 and α1-ß1 heterodimer determines whether the Na,K-ATPase acts as a positive or negative regulator of intercellular adhesion.

Evaluación del cumplimiento de la pesquisa auditiva en pacientes ingresados al Hospital Garrahan entre marzo de 2012-2013 / Evaluation of compliance with hearing screening of patients admitted to Garrahan Hospital from March 2012-2013

Objetivos: 1) Evaluar el cumplimiento del Programa Nacional de Detección Temprana y Atención de la Hipoacusia. 2) Correlacionar los resultados con la presencia o ausencia de cobertura social. 3) Evaluar la información brindada a los padres en contenido y la demora en efectuar la prueba. Métodos: estudio observacional y transversal. Se incluyeron todos los pacientes entre 1/03/12 y 31/03/13 que consultaron espontáneamente en el Hospital Garrahan y requirieron hospitalización en la sala de internación conjunta del Área de Neonatología. Se analizaron los datos obtenidos por interrogatorio, historia clínica y encuesta realizada a los padres. Se empleó estadística descriptiva y Chi2 según necesidad. Resultados: Ingresaron 153 pacientes. Mediana de edad: 21 días (16-30). Cobertura social 25% (38/153). 30% (46/153) tenían efectuada OEA. 30 tenían turno emitido, 44 habían recibido la orden médica y 33 de los 107 no evaluados no tenían ningún tipo de vinculación con la prueba. En el 34% (13/38) de los casos con obra social vs el 17% (20/115) de los casos sin cobertura se observó incumplimiento total (p 0,02).Con respecto a la información de los padres 35 /153 pacientes (23%) habían sido informados sobre la importancia de esta prueba. Discusión: Son escasos los pacientes evaluados previo al egreso de la maternidad o dentro del primer mes de vida. Poseer cobertura social no facilita el cumplimiento de la ley. Los padres carecen de información sobre la importancia de la misma (AU)

Aims: 1) To evaluate compliance with the National Program for Early Detection and Care of Hearing Loss. 2) To correlate results with presence or absence of health insurance coverage. 3) To evaluate the quality of information provided to the parents and the delay in taking the test. Methods: An observational and cross-sectional study. All patients who consulted spontaneously at Hospital Garrahan between 1/03/12 and 31/03/13 and who required admission to the neonatology ward were included. Data obtained from the clinical chart and from an interview and questionnaire administered to the parents were analyzed. Depending on the data descriptive statistics and chi-square test were used. Results: 153 patients were admitted. Mean age was 21 days (16-30). Health care coverage: 25% (38/153). Acoustic otoemissions (AOE) were performed in 30% (46/153). Overall, 30 had been called for an appointment, 44 had received the medical indication, and 33 of 107 infants who were not evaluated had not been in touch with the test. In 34% (13/38) of the cases with health insurance coverage vs 17% (20/115) without total incompliance was observed (p 0.02). Regarding information for parents, 35/153 (23%) had been informed on the importance of the test. Conclusion: Few patients are screened on discharge from the maternity clinic or within the first month of life. Health insurance coverage does not facilitate compliance with the law. Parents do not receive information on the importance of the test (AU)

Effect of aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing amino acids on Leishmania spp. chemotaxis.

In the sand-fly mid gut, Leishmania promastigotes are exposed to acute changes in nutrients, e.g. amino acids (AAs). These metabolites are the main energy sources for the parasite, crucial for its differentiation and motility. We analysed the migratory behaviour and morphological changes produced by aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing AAs in Leishmania amazonensis and Leishmania braziliensis and demonstrated that L-methionine (10-12 m), L-tryptophan (10-11 m), L-glutamine and L-glutamic acid (10-6 m), induced positive chemotactic responses, while L-alanine (10-7 m), L-methionine (10-11 and 10-7 m), L-tryptophan (10-11 m), L-glutamine (10-12 m) and L-glutamic acid (10-9 m) induced negative chemotactic responses. L-proline and L-cysteine did not change the migratory potential of Leishmania. The flagellum length of L. braziliensis, but not of L. amazonensis, decreased when incubated in hyperosmotic conditions. However, chemo-repellent concentrations of L-alanine (Hypo-/hyper-osmotic conditions) and L-glutamic acid (hypo-osmotic conditions) decreased L. braziliensis flagellum length and L-methionine (10-11 m, hypo-/hyper-osmotic conditions) decreased L. amazonensis flagellum length. This chemotactic responsiveness suggests that Leishmania discriminate between slight concentration differences of small and structurally closely related molecules and indicates that besides their metabolic effects, AAs play key roles linked to sensory mechanisms that might determine the parasite's behaviour.

Megalin mediates transepithelial albumin clearance from the alveolar space of intact rabbit lungs.

The alveolo-capillary barrier is effectively impermeable to large solutes such as proteins. A hallmark of acute lung injury/acute respiratory distress syndrome is the accumulation of protein-rich oedema fluid in the distal airspaces. Excess protein must be cleared from the alveolar space for recovery; however, the mechanisms of protein clearance remain incompletely understood. In intact rabbit lungs 29.8 ± 2.2% of the radio-labelled alveolar albumin was transported to the vascular compartment at 37°C within 120 min, as assessed by real-time measurement of 125I-albumin clearance from the alveolar space. At 4°C or 22°C significantly lower albumin clearance (3.7 ± 0.4 or 16.2 ± 1.1%, respectively) was observed. Deposition of a 1000-fold molar excess of unlabelled albumin into the alveolar space or inhibition of cytoskeletal rearrangement or clathrin-dependent endocytosis largely inhibited the transport of 125I-albumin to the vasculature, while administration of unlabelled albumin to the vascular space had no effect on albumin clearance. Furthermore, albumin uptake capacity was measured as about 0.37 mg ml−1 in cultured rat lung epithelial monolayers, further highlighting the (patho)physiological relevance of active alveolar epithelial protein transport. Moreover, gene silencing and pharmacological inhibition of the multi-ligand receptor megalin resulted in significantly decreased albumin binding and uptake in monolayers of primary alveolar type II and type I-like and cultured lung epithelial cells. Our data indicate that clearance of albumin from the distal air spaces is facilitated by an active, high-capacity, megalin-mediated transport process across the alveolar epithelium. Further understanding of this mechanism is of clinical importance, since an inability to clear excess protein from the alveolar space is associated with poor outcome in patients with acute lung injury/acute respiratory distress syndrome.

Management of larynx and trachea donors.

INTRODUCTION: Laryngeal transplantation is a possibility for patients with irreversible laryngeal disease, such as complex trauma and larynx cancer. The objective of performing this procedure was to solve problems that these patients face with a laryngectomy. The medical literature has reviews about larynx transplantations, but almost nothing about the larynx donor. The following is our experience on management of these donors. MATERIALS AND METHODS: Selection criteria was as follows: (1) 18-50 years old; (2) gender and ABO blood type matched between donor and recipient; (3) No abuse of tobacco, cocaine, and marijuana, (4) tracheal intubation time <3 days; and (5) time in the intensive care unit <7 days. The preservation was simple hypothermia with larynx infusion via the carotid artery with University of Wisconsin solution. RESULTS: Between 2001 and 2006, we managed 25 donors, among whom 12 grafts were discarded. The 13 larynx donors were of average age 27.2 +- 7.9 years and their cause of death was head trauma. Each was of male and 12 were multiorgan donors. Three donors had previous consumption of tobacco and 2 donors of marijuana. There were 2 cases of acute rejection episodes. Graft survival rate at 2 years was 90%. DISCUSSION: These donors may have differences from other multiorgan donors: (1) they do not require strict fluid management; (2) vasoactive agents may be used in higher doses than in organ donors, and (3) the larynx tolerates hemodynamic instability. It was necessary to use some donors who had used addictive substances, showing that some selection criteria may be flexible. There was no conflict between thoracic surgeons and larynx surgeons. The priority always was for life-saving organs. Family consent was sometimes difficult because of the retrieval times and body donor reconstruction. The larynx surgery retrieval demanded an additional 2-5 hours during routine multiorgan donor surgery, and always the family asked about body reconstruction. The body appearance was always preserved.

Indicadores de sintomas depresivos en una muestra de jóvenes de 12 a 17 años de edad con diabetes mellitus tipo I / Indicators of depression symptoms in a sample of 12 to 17 year-old youths with diabetes mellitus type I

The purpose of this study was to find out what percent of a group of patients 12 to 17 years old and with a diagnosis of Diabetes Mellitus type I have depressive symptomatology. We also wanted to know if there were gender differences in regard to depressive symtomatology in this group. We used a revised and adapted spanish translation of the Beck Depression Inventory, the IDB-R. It was administered to a group of 49 patients ages 12 to 17 with Diabetes Mellitus type I. The mean score of the group at the IDR-R was 9.33, which according to the instrument represents absence of depressive symptomatology. We found that 36.7of this group obtained a score greater than 10 in the IDB-R which according to this instrument, it means that depressive symptomatology was present. The symptoms most reported by the females were difficulties taking decisions and sleep problems. The symptom most reported by the males was change in appetite.

Magnetic properties of ferromagnetic quasi-1D copper-peptide compounds: exchange interactions and very low temperature phase transitions.

The magnetic properties of the Cu(II)-peptide compounds (L-tyrosyl-L-leucinato)Cu(II) and (L-tryptophyl-glycinato)Cu(II), to be identified as Cu(II)Tyr-Leu and Cu(II)Trp-Gly, respectively, have been investigated by specific heat (0.08 < T < 28 K), dc magnetization (2 < T < 80 K, with B(0) = mu(o)H < or = 9 T), and ac magnetic susceptibility (with B(0) = 0 for 0.03 < T < 3 K and B(0) up to 9 T for 2 < T < 80 K) measurements. Above approximately 1 K, the specific heat and magnetization of both compounds display a ferromagnetic (FM) spin chain behavior sustained by syn-anti carboxylate bridges connecting equatorially Cu(II) ions at about 5 A. To model this behavior, we calculated the eigenvalues of Heisenberg chains with up to 20 spins 1/2 and used the method of Bonner and Fisher. A global fit of the model to the specific heat and magnetization data gives 2J(0)/k(B) = 3.60(5) K and 2.59(5) K for the intrachain exchange interactions in Cu(II)Tyr-Leu and Cu(II)Trp-Gly, respectively (H(ex)(i,j) = -2J(0) S(i).S(j)). These values of 2J(0) are discussed in terms of structural properties of the carboxylate bridges in the two compounds. Using the parameters obtained from the global fit, we calculated isothermal susceptibilities in agreement with the ac susceptibilities measured with small applied dc magnetic fields. However, the ac susceptibility measured with applied dc fields larger than 1 T lie between the values calculated for the isothermal and adiabatic susceptibilities. At 0.16 K for Cu(II)Tyr-Leu and 0.53 K for Cu(II)Trp-Gly, the observed specific heat and magnetic susceptibility display peaks associated to three-dimensional magnetic phase transitions. The interchain exchange couplings 2J(1) producing the 3D magnetic order are ferromagnetic and have magnitudes 2J(1)/k(B) approximately 0.015 and 0.073 K for Cu(II)Tyr-Leu and Cu(II)Trp-Gly, respectively.

Weak exchange interaction supported by a biologically relevant long chemical bridge in a Cu-peptide model compound.

The copper complex of the dipeptide L-alanyl-L-phenylalanine, catena-(L-alaninate-L-phenylalaninate-copper(II) monohydrate), identified as Cu(II)Ala-Phe, provides a convenient system to study a weak exchange interaction between unpaired spins transmitted through a biologically relevant long chemical bridge (18.34 A). In this complex, the copper ions are arranged in two symmetry-related anisotropic layers parallel to the ab plane at 13.17 A, separated by a double layer of water molecules. The equatorial-equatorial bridge considered as the most relevant path for exchange interactions between copper ions in neighbor layers contains 11 diamagnetic atoms (including three hydrogens), with two covalent amidate bridges plus three weak and moderate H bonds that go across the water layer. This interaction was studied using electron paramagnetic resonance in single-crystal samples, at 9.5 and 34.5 GHz. The measured magnitude of the interlayer interaction, |J3|/kB = 1.7(2) x 10(-3) K, is discussed in terms of values obtained for similar paths in other model compounds and in proteins. These results in model systems provide information that may be important in understanding biological functions at the molecular level.

Heterochromatin and chromosome evolution: a FISH probe of Cebus apella paraguayanus (Primate: Platyrrhini) developed by chromosome microdissection

Neotropical Primate karyotypes are highly variable, particularly in the heterochromatic regions, not only regarding the amount of heterochromatin, but also the composition. G and C banding and FISH techniques provide useful information to characterize interspecific relationships. We used chromosome microdissection to develop a FISH probe of the chromosome 11 heterochromatic block (11qHe+) of Cebus apella paraguayanus (CAPp). Fragments of the 11qHe+ microdissected from fibroblast cell culture were collected in a PCR tube, amplified by degenerate oligonucleotide primer-PCR and subsequently labeled. The specificity of the FISH probe was confirmed in metaphases of some Ceboidea species. Signals were located in the He+ of chromosomes 4, 11, 12, 13, and 19 of CAPp and in the He+ of chromosomes 4, 12 and 13 of C. a. nigritus (CAPn); no signals were observed when other Ceboidea species were analyzed. We propose that the heterochromatin observed in CAPp and CAPn is specific for these species. We consider this C. apella heterochromatin identity as a possible key for the interpretation of chromosomal evolution in these Ceboidea.

Treatment of stage I and II Hodgkin's lymphoma with ABVD chemotherapy: results after 7 years of a prospective study.

BACKGROUND: Chemotherapy with ABVD (doxorubicin, bleomycin, vinblastine and darcarbacine) schedule is the standard treatment for advanced Hodgkin's lymphoma. Certain facts, including a low toxicity compared with MOPP/ABV (mechlorethamine, vincristine, procarbazine, prednisone, doxorubicin, bleomycin and vinblastine) and minimal potential for inducing second neoplasias or patient sterility, support the use of ABVD to treat early disease stages. In the present study, we prospectively evaluated the long-term efficacy and toxicity of six cycles of ABVD as treatment for early-stage Hodgkin's lymphoma. PATIENTS AND METHODS: From January 1990 to June 2002, 95 patients with stage I and II Hodgkin's lymphoma were treated with six ABVD cycles. Fifteen patients who met the criteria for mediastinal bulky disease also received further radiotherapy on the mediastinum. RESULTS: After six cycles, 89 patients (94%) showed a complete response (CR) and six patients (6%) showed a partial response (PR). These PRs became CRs after radiotherapy. After a median follow-up of 78 months, 14 patients had relapsed and three had died. Overall survival and progression-free survival rates at 7 years were 96% and 84%, respectively. For patients with stage IA and IIA without mediastinal bulky disease, the survival rates were 97% and 88%, respectively. CONCLUSIONS: The administration of six ABVD cycles is an effective and safe treatment in patients with stage I and II Hodgkin's lymphoma.

Normalización de la medición de la actividad de la Na+/K+-ATPasa en glóbulos rojos humanos / Normalization of the measurement activity of the Na+/K+-ATPase in human erythrocytes

Los fantasmas de glóbulos rojos (FGR) humanos obtenidos de sujetos sanos muestran actividad de la Na+/K+-ATpasa de 1,68 ñ 0,08 nmoles Pi/mg proteína x min (n=65; edad: 30 a 60 años). No hubo diferencias entre sexos, tampoco entre muestras obtenidas en ayuno o postprandiales. Comprobamos que la sangre debe mantenerse en frío (0ºC) si no es procesada de inmediato. Obtenidos los FGR a 0ºC, la actividad enzimática no varía entre el momento de la toma y las 4 h; pero si varía significativamente a las 24 y 48 h. Los FGR conservados a -40ºC, mantienen la actividad por 48 h. En dos voluntarios sanos tratados con digoxina por una semana observamos una disminución en la actividad enzimática el primer día (17 por ciento y 22 por ciento de control, respectivamente). Los niveles de digoxina en suero no mostraron paralelismo con la actividad enzimática y fueron siempre menores de 0,7 ng/ml. Conclusión: Se dan las pautas metodológicas para obtener muestras útiles en clínica

Secondary prophylactic G-CSF (filgrastim) administration in chemotherapy of stage I and II Hodgkin's lymphoma with ABVD.

UNLABELLED: The purpose of this study was to determine the effect of granulocyte colony-stimulating factor (filgrastim, G-CSF) for maintenance of chemotherapy dose-intensity in patients with stage I or II Hodgkin's lymphoma treated with six cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD). Fifty-six patients with stage I or II Hodgkin's lymphoma treated with ABVD were eligible for secondary prophylactic G-CSF administration because of neutropenia (absolute neutrophil count < 1 x 10(9) /L) causing treatment delay or febrile neutropenia. Patients received 300 microg (total dose) of G-CSF (filgrastim) subcutaneously on days 3 to 7 and 17 to 21 of each cycle in order to prevent dose reduction or delay in subsequent cycles of treatment continuing the G-CSF until completion of chemotherapy. Results showed that 30 (54%) of the patients required the use of G-CSF, 26 (47%) during the first or second cycle. After G-CSF administration delay in chemotherapy did not occur in 25 patients, whereas delays in the fifth or sixth cycle occurred in four patients. Despite treatment with G-CSF, one patient had febrile neutropenia. Dose intensity greater than 90% of that planned was delivered to more the 85% of patients. IN CONCLUSION: Secondary prophylactic G-CSF administration was necessary in more than half of patients with stage I or II Hodgkin's lymphoma during chemotherapy with ABVD. The use of G-CSF allowed maintenance of chemotherapy schedule and dose intensity in the majority of patients.

Efecto de la amilorida y su derivado diclorobenzamil sobre la auricula aislada del acure (Cavia porcellus): interaccion con otras maniobras inotropicas / Effect of amiloride and dichlorobenzamil derivative in the guinea pig atria: interaction with other inotropic mechanisms

Se estudiaron los efectos cronotrópico e inotrópico de la Amilorida (AMI) y la dicloro-benzamil-Amilorida (DCB-AMI) sobre las aurículas aislada del acure, así como la interacción de estas drogas con la beta-metil-digoxina (BM_DIGO), la epinefrina y la disminución del potasio extracelular (de 4 a 1 mM). La AMI (1 mM) causa un efecto inotrópico positivo y cronotrópico negativo, independientes del sistema autonómico. La DCB-AMI causa um efecto bimodal sobre la fuerza de contracción: la aumenta a bajas dosis pero la disminuye a concentraciones mayores de 10(-6) M. También disminuye levemente la frecuencia sinusal. El efecto de la AMI sobre el automatismo sinusal no es alterado por la BM-DIGO. En cambio, la AMI ((10(-3 M) disminuye el efecto inotrópico positivo de la BM-DIGO e incrementa la dosis tóxica en preparaciones aisladas. La curva dosis-respuesta a la epinefrina no varía en presencia de AMI. Resultados similares se obtuvieron con DCB-AMI (2 x 10(-7 M). El incremento de contractilidad que se observa al disminuir la concentración extracelular de potasio a 1 mM no se altera en presencia de AMI. La actividad de la Na+/K+ ATPasa dependiente de Mg++ de la fracción microsomal obtenida del corazón del acure disminuye en 10 por ciento aproximadamente en presencia de AMI (1nM). Por otra parte, el efecto inhibitorio sobre la enzima obtenido con ouabaína no varía con esta droga. En conclusión, nuestros resultados sugieren múltiples efectos de la AMI y DCB-AMI sobre el corazón del acure. La inhibición del intercambiador Na+/Ca++ explica solo parte de ellos; el bloqueo de los canales lentos parece fundamental para explicar nuestras observaciones.