The potential influence of gastric acid secretion during fasting on digestion time in leopard sharks (Triakis semifasciata) Article

Papastamatiou, YP. (2007). The potential influence of gastric acid secretion during fasting on digestion time in leopard sharks (Triakis semifasciata) . COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY, 147(1), 37-42. 10.1016/j.cbpa.2006.11.012

cited authors

  • Papastamatiou, YP

authors

abstract

  • Vertebrates are known to differ in their response of gastric acid secretion during periods of fasting, yet the reasons for these differences remain unclear. Previously, continuous measurements of gastric pH in leopard sharks (Triakis semifasciata) had determined that acid secretion in this species is continuous. In order to determine if maintaining an empty acidic stomach may reduce digestion time of a subsequent meal, a simple descriptive model based on acid secretion rates was developed. In vivo gastric acid secretion rates were measured using an auto-titration technique. Acid secretion rates were pH dependent, with rates of 6.1 ± 3.0 (± 1 SD) mmol/h when gastric pH was > 2.5, and 1.7 ± 0.8 mmol/h when pH was 2.0-2.5. Analysis by Western blots suggests that pepsin secretion occurs within 1 h of feeding, and that there is a de-coupling of acid and pepsin secretion. The model estimates that digestion time can be reduced by 5.7 ± 1.3 h and pepsin activity increased by 10-100% during that time if the stomach is acidic before feeding. Gastric acid secretion during fasting is hypothesized to reduce digestion time of a subsequent meal in frequently feeding sharks, which may be advantageous for exploiting resources that are spatially and temporally unpredictable. © 2006 Elsevier Inc. All rights reserved.

publication date

  • January 1, 2007

published in

Digital Object Identifier (DOI)

start page

  • 37

end page

  • 42

volume

  • 147

issue

  • 1