title: Food composition influences metabolism, heart rate and organ growth during digestion in Python regius.
abstract: Digestion in pythons is associated with a large increase in oxygen consumption (SDA), increased cardiac output and growth in visceral organs assisting in digestion. The processes leading to the large postprandial rise in metabolism in snakes is subject to opposing views. Gastric work, protein synthesis and organ growth have each been speculated to be major contributors to the SDA. To investigate the role of food composition on SDA, heart rate (HR) and organ growth, 48 ball pythons (Python regius) were fed meals of either fat, glucose, protein or protein combined with carbonate. Our study shows that protein, in the absence or presence of carbonate causes a large SDA response, while glucose caused a significantly smaller SDA response and digestion of fat failed to affect metabolism. Addition of carbonate to the diet to stimulate gastric acid secretion did not increase the SDA response. These results support protein synthesis as a major contributor to the SDA response and show that increased gastric acid secretion occurs at a low metabolic cost. The increase in metabolism was supported by tachycardia caused by altered autonomic regulation as well as an increased non-adrenergic, non-cholinergic (NANC) tone in response to all diets, except for the lipid meal. Organ growth only occurred in the small intestine and liver in snakes fed on a high protein diet.
authors.affiliation: Zoophysiology, Department of Bioscience, Aarhus University, Denmark.
authors.forename: Poul Secher
authors.initials: PS
authors.lastname: Henriksen
authors.affiliation: Zoophysiology, Department of Bioscience, Aarhus University, Denmark. Electronic address: sanneenok@gmail.com.
authors.forename: Sanne
authors.initials: S
authors.lastname: Enok
authors.affiliation: Zoophysiology, Department of Bioscience, Aarhus University, Denmark.
authors.forename: Johannes
authors.initials: J
authors.lastname: Overgaard
authors.affiliation: Zoophysiology, Department of Bioscience, Aarhus University, Denmark.
authors.forename: Tobias
authors.initials: T
authors.lastname: Wang
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure; D017821:Boidae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D002254:Carbonates / Q000494:pharmacology; D004044:Dietary Proteins / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006003:Glycogen / Q000032:analysis; D006339:Heart Rate; D008055:Lipids / Q000032:analysis; D009929:Organ Size; D010101:Oxygen Consumption; D019518:Postprandial Period
chemical_list: D002254:Carbonates; D004044:Dietary Proteins; D008055:Lipids; D006003:Glycogen; D005947:Glucose
keywords: Cardiovascular; Digestion; Gastric work; Organ growth; Postprandial response; Python regius; Regulation; Specific dynamic action