Effects of feeding and digestion on myocardial contractility and expression of calcium-handling proteins in Burmese pythons (Python molurus)

Autor(es)

Vasconcelos, Eliton da Silva ^[1] ; Kalinin, Ana Lucia ^[1] ; Cipriano, Rafael Correa ^[1] ; Beserra, Samuel dos Santos ^[2] ; Lopes, Andre Guelli ^[1] ; Costa Leite, Cleo Alcantara ^[1] ; Monteiro, Diana Amaral ^[1]

Afiliação do(s) autor(es)

^[1] Fed Univ Sao Carlos UFSCar, Dept Physiol Sci, Sao Carlos, SP - Brazil

^[2] Fed Univ Sao Paulo UNIFESP, Dept Biophys, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY; v. 240, FEB 2020.
• Citações Web of Science: 1

Resumo

Pythons are important models of studies on postprandial metabolism because their physiological responses are exacerbated when digesting large prey. Prior studies of these animals have shown hypertrophy of the cardiac tissue 2 to 3 days after feeding, coinciding with the peak of the specific dynamic action (SDA), but the consequences of this remodeling in myocardial contractility have not been studied, which is the purpose of this work. Specimens of Python molurus were divided into two groups: a Digesting group (2 days after feeding, at the peak of SDA), and a Fasting group (28 days after feeding). When compared to the Fasting group, the Digesting group showed higher relative ventricular mass and calcium-handling protein expression such as sarcoplasmic reticulum Ca2+-ATPase (SERCA), phospholamban (PLB), and the Na+/Ca2+ exchanger (NCX). Digesting pythons also exhibited significant increases in the cardiac contraction force (Fc), rates of force development and relaxation, and cardiac pumping capacity. Therefore, the higher SERCA, PLB and NCX expression levels increased cytosolic Ca2+ transient amplitude, improving myofilament force. These changes are crucial to maintain cardiac output and a relatively high and continuous blood flow required by metabolic expenditure that occurs in postprandial animals. (AU)

• Processo FAPESP: 08/57712-4 - Instituto Nacional de Pesquisas em Fisiologia Comparada
• Beneficiário: Augusto Shinya Abe
• Modalidade de apoio: Auxílio à Pesquisa - Temático