Video Experimental Relacionado

Updated: May 6, 2026

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes

Published on: September 18, 2017

La insulina causa efectos inotrópicos positivos [Ca2+]i-dependientes y [Ca2+]i-independientes en el miocardio humano

Dirk von Lewinski¹, Sebastian Bruns, Stefanie Walther

¹Abteilung Kardiologie und Pneumologie, Georg-August-Universität Göttingen, Göttingen, Germany.

|May 11, 2005

Resumen

La insulina mejora la contracción del músculo cardíaco en los corazones humanos con insuficiencia a través de una vía de la PI-3-cinasa. Esto implica un mayor manejo de calcio y puede ser clínicamente relevante para el tratamiento de la insuficiencia cardíaca.

Área de la Ciencia:

Cardiología Cardiología.
Biología Molecular Biología Molecular
Fisiología Fisiología Fisiología.

Sus antecedentes:

Se conocen los efectos inotrópicos positivos de la insulina, pero la transducción de la señal y la dependencia del sustrato no están claros.
Este estudio investiga las respuestas inotrópicas de la insulina y la señalización en el miocardio humano.

Objetivo del estudio:

Aclarar los mecanismos de transducción de señales y la dependencia del sustrato de los efectos inotrópicos positivos de la insulina en el miocardio humano.
Identificar las vías específicas involucradas en la acción de la insulina sobre la contractilidad cardíaca.

Principales métodos:

Los experimentos utilizaron trabéculas aisladas de corazones humanos con fallas.
Se evaluó la fuerza de contracción isométrica, los transitorios intracelulares de Ca2+, el contenido de Ca2+ en SR y la sensibilidad al Ca2+ del miofillamento.
Caminos de señalización probados mediante la inhibición de enzimas y receptores clave, incluida la PI-3-cinasa y el intercambiador Na+/Ca2+.

Principales resultados:

La insulina demostró efectos inotrópicos positivos dependientes de la concentración y dependientes del sustrato.
La inhibición de la fosfatidilinositol-3-cinasa (PI-3-cinasa) y el intercambiador Na+/Ca2+ previene parcial o completamente los efectos de la insulina.
La insulina aumentó los transitorios intracelulares de Ca2+, el contenido de Ca2+ de la SR y la sensibilidad al Ca2+ del miofillamento.

Conclusiones:

La insulina ejerce efectos inotrópicos positivos Ca2 + dependientes e independientes a través de una vía dependiente de la PI-3-cinasa en el miocardio humano fallido.
El aumento del calcio intracelular se origina en parte por el aumento del intercambio de Na + / Ca2 + en modo inverso, lo que lleva a un aumento de la carga de Ca2 + SR.
Estos efectos no genómicos de la insulina pueden tener importancia clínica, particularmente en contextos como las infusiones de insulina-glucosa-potasio.

Más Videos Relacionados

Contractions of Human-iPSC-derived Cardiomyocyte Syncytia Measured with a Ca-sensitive Fluorescent Dye in Temperature-controlled 384-well Plates

Contractions of Human-iPSC-derived Cardiomyocyte Syncytia Measured with a Ca-sensitive Fluorescent Dye in Temperature-controlled 384-well Plates

Published on: October 18, 2018

Implantation of an Isoproterenol Mini-Pump to Induce Heart Failure in Mice

Implantation of an Isoproterenol Mini-Pump to Induce Heart Failure in Mice

Published on: October 3, 2019

Videos de Conceptos Relacionados

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers

Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which...

Heart Failure Drugs: Inotropic Agents

Heart Failure Drugs: Inotropic Agents

Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long...

Heart Failure Drugs: Inhibitors of Renin-Angiotensin System

Heart Failure Drugs: Inhibitors of Renin-Angiotensin System

The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral...

Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are...

Insulin: Dosing Regimen and Adverse Effects

Insulin: Dosing Regimen and Adverse Effects

Insulin-replacement therapy usually includes both long-acting insulin (basal) and short-acting insulin (to cater to postprandial needs). In a diverse group of type 1 diabetes patients, the average daily insulin dose is typically 0.5-0.7 units/kg body weight. However, obese patients and pubertal adolescents may need more due to insulin resistance.
The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror...

Myocarditis I: Introduction

Myocarditis I: Introduction

Myocarditis is inflammation of the myocardium, which is the muscular layer of the heart.EtiologyMyocarditis has a diverse etiology, including a wide range of infectious and non-infectious causes:Infectious CausesViral: Common viruses include Coxsackie A and B, adenovirus, parvovirus B19, enteroviruses, and influenza A.Bacterial: Examples include infections caused by Streptococcus, Staphylococcus, and Mycoplasma species.Rickettsial: Infections like Rocky Mountain spotted fever can result in...