Can the Immune System Protect after Repeated Myocardial Injury? Blog post by Jasmin Skinner Regardless of the cause and specific etiology, cardiomyopathies impair the hearts ability to pump blood (1). Possible consequences include arrhythmia, heart failure, and death, and in some instances a recurrence of cardiac injury can occur. This may result in a chronically enlarged heart, known as dilated cardiomyopathy (2). While the immune response to a single cardiomyopathic injury has been extensively studied, the immune response after repeated injury has not been as thoroughly characterized (3). If the immune response to recurring cardiomyopathy can adapt and reduce the effects of repeated cardiac injury, it may represent a potential target for preventative treatment in high risk individuals. A recent publication from Tiwary et al., investigated this pathway in a murine model, and is discussed in this blog (3). https://insidescientific.com/wp-content/uploads/2023/01/Cardiovascular-autonomic-dysfunction-in-the-post-COVID-landscape-detection-and-management_F1.jpg Cardiovascular Autonomic Dysfunction in the Post-COVID Landscape: Detection and Management This webinar features Artur Fedorowski, MD, PhD, as he describes the relationship between cardiovascular dysautonomia after COVID-19, and the diagnostics behind detecting Long COVID or Post-acute Sequalae of COVID-19. WATCH HERE.

Study parameters and repeated cardiac injury protocol

To determine whether the mouse immune system is capable of adapting and mounting a cytoprotective response to repeated cardiac injury, 10 week old male and female mice were injected with isoproterenol (ISO), a drug used to treat bradycardia conditions that causes increased heart rate and contractility, peripheral vasodilation, and relaxation of the bronchial, gastrointestinal, and uterine smooth muscle (4); control mice received vehicle injections. All mice were allowed to recover for 7 days after injection, before receiving a second dose of either ISO or the vehicle solution. Additionally, to determine whether this cytoprotective response was maintained, they reinjected the ISO-pretreated mice with a second ISO injection 21 and 42 days after the initial injection (3). To assess the severity of cardiac injury, Evans blue dye uptake and serum troponin I levels were monitored. Troponin, as well as other biomolecules, is released when the heart muscle has been damaged, making it an excellent indicator to determine whether ISO-induced cardiac injury is lessened after pre-exposure. Additionally, 2D echocardiographic studies were performed to determine left ventricular (LV) regional wall motion, and LV contractility by Langendorff perfusion (3). [fusion_builder_column type="1_1" layout="1_1" align_self="auto" content_layout="column" align_content="flex-start" valign_content="flex-start" content_wrap="wrap" spacing="" center_content="no" column_tag="div" link="" target="_self" link_description="" min_height="" hide_on_mobile="small-visibility,medium-visibility,large-visibility" sticky_display="normal,sticky" class="" id="" background_image_id="" type_medium="" type_small="" order_medium="0" order_small="0" spacing_left_medium="" spacing_right_medium="" spacing_left_small="" spacing_right_small="" spacing_left="" spacing_right="" margin_top_medium="" margin_bottom_medium="" margin_top_small="" margin_bottom_small="" margin_top="" margin_bottom="" padding_top_medium="" padding_right_medium="" padding_bottom_medium="" padding_left_medium="" padding_top_small="" padding_right_small="" padding_bottom_small="" padding_left_small="" padding_top="" padding_right="" padding_bottom="0px" padding_left="" hover_type="none" border_sizes_top="" border_sizes_right="" border_sizes_bottom="" border_sizes_left="" border_color="" hue="" saturation="" lightness="" alpha="" border_style="solid" border_radius_top_left="" border_radius_top_right="" border_radius_bottom_right="" border_radius_bottom_left="" box_shadow="no" box_shadow_vertical="" box_shadow_horizontal="" box_shadow_blur="0" box_shadow_spread="0" box_shadow_color="" box_shadow_style="" z_index_subgroup="regular" z_index="" z_index_hover="" overflow="" background_type="single" gradient_start_color="" gradient_end_color="" gradient_start_position="0" gradient_end_position="100" gradient_type="linear" radial_direction="center center" linear_angle="180" background_color="" background_image="" lazy_load="avada" skip_lazy_load="" background_position="left top" background_repeat="no-repeat" background_blend_mode="none" render_logics="" sticky="off" sticky_devices="small-visibility,medium-visibility,large-visibility" sticky_offset="" absolute="off" absolute_top="" absolute_right="" absolute_bottom="" absolute_left="" filter_type="regular" filter_hover_element="self" filter_hue="0" filter_saturation="100" filter_brightness="100" filter_contrast="100" filter_invert="0" filter_sepia="0" filter_opacity="100" filter_blur="0" filter_hue_hover="0" filter_saturation_hover="100" filter_brightness_hover="100" fi