Myocardial Dysfunction after Severe Food Restriction Is Linked to Changes in the Calcium-Handling Properties in Rats

• Published in: Nutrients Vol. 11; no. 9; p. 1985
• Main Authors: Deus, Adriana Fernandes de, Silva, Vítor Loureiro da, de Souza, Sérgio Luiz Borges, Mota, Gustavo Augusto Ferreira, Sant'Ana, Paula Grippa, Vileigas, Danielle Fernandes, Lima-Leopoldo, Ana Paula, Leopoldo, André Soares, Campos, Dijon Henrique Salomé de, de Tomasi, Loreta Casquel, Padovani, Carlos Roberto, Kolwicz, Jr, Stephen C, Cicogna, Antonio Carlos
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 22.08.2019; MDPI
• Subjects: Adaptation; Adiposity; Animals; Body fat; Ca2+-transporting ATPase; Calcium; Calcium (reticular); Calcium - metabolism; Calcium channels (L-type); Calcium Channels, L-Type - metabolism; Calcium ions; Calcium Signaling; calcium transient proteins; Caloric Restriction; Calsequestrin; Cardiac function; Cardiac muscle; Contraction; Correlation analysis; Disease Models, Animal; Exercise; Fluorides; Food; Food availability; Food intake; Handling; Heart Diseases - etiology; Heart Diseases - metabolism; Heart Diseases - pathology; Heart Diseases - physiopathology; Heart failure; Heart function; heart impairment; L-type calcium channel; Laboratory animals; Male; Malnutrition; Malnutrition - complications; Malnutrition - metabolism; Malnutrition - pathology; Malnutrition - physiopathology; Mitochondria, Heart - metabolism; Mitochondria, Heart - pathology; Myocardial Contraction; Myocardium; Myocytes, Cardiac - metabolism; Myocytes, Cardiac - pathology; Na+/Ca2+ exchanger; papillary muscle assay; Papillary Muscles - metabolism; Papillary Muscles - pathology; Papillary Muscles - physiopathology; Phospholamban; Protein expression; Proteins; Rats, Inbred WKY; Ryanodine receptors; Sarcoplasmic reticulum; Sarcoplasmic Reticulum Calcium-Transporting ATPases - metabolism; SERCA2a; Weight Loss; Brazil; United States > US; malnutrition; papillary muscle assay; SERCA2a; L-type calcium channel; calcium transient proteins; heart impairment
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu11091985

Severe food restriction (FR) impairs cardiac performance, although the causative mechanisms remain elusive. Since proteins associated with calcium handling may contribute to cardiac dysfunction, this study aimed to evaluate whether severe FR results in alterations in the expression and activity of Ca -handling proteins that contribute to impaired myocardial performance. Male 60-day-old Wistar-Kyoto rats were fed a control or restricted diet (50% reduction in the food consumed by the control group) for 90 days. Body weight, body fat pads, adiposity index, as well as the weights of the soleus muscle and lung, were obtained. Cardiac remodeling was assessed by morphological measures. The myocardial contractile performance was analyzed in isolated papillary muscles during the administration of extracellular Ca and in the absence or presence of a sarcoplasmic reticulum Ca -ATPase (SERCA2a) specific blocker. The expression of Ca -handling regulatory proteins was analyzed via Western Blot. Severe FR resulted in a 50% decrease in body weight and adiposity measures. Cardiac morphometry was substantially altered, as heart weights were nearly twofold lower in FR rats. Papillary muscles isolated from FR hearts displayed mechanical dysfunction, including decreased developed tension and reduced contractility and relaxation. The administration of a SERCA2a blocker led to further decrements in contractile function in FR hearts, suggesting impaired SERCA2a activity. Moreover, the FR rats presented a lower expression of L-type Ca channels. Therefore, myocardial dysfunction induced by severe food restriction is associated with changes in the calcium-handling properties in rats.