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

Publication date: Available online 30 October 2019Source: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular BiologyAuthor(s): Eliton da Silva Vasconcelos, Ana Lúcia Kalinin, Rafael Correa Cipriano, Samuel dos Santos Beserra, André Guelli Lopes, Cléo Alcântara da Costa Leite, Diana Amaral MonteiroAbstractPythons 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 chang...
Source: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology - Category: Molecular Biology Source Type: research