Selected regulation of gastrointestinal acid-base secretion and tissue metabolism for the diamondback water snake and Burmese python

Stephen M. Secor, Josi R. Taylor, Martin Grosell

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Snakes exhibit an apparent dichotomy in the regulation of gastrointestinal (GI) performance with feeding and fasting; frequently feeding species modestly regulate intestinal function whereas infrequently feeding species rapidly upregulate and downregulate intestinal function with the start and completion of each meal, respectively. The downregulatory response with fasting for infrequently feeding snakes is hypothesized to be a selective attribute that reduces energy expenditure between meals. To ascertain the links between feeding habit, whole-animal metabolism, and GI function and metabolism, we measured preprandial and postprandial metabolic rates and gastric and intestinal acid-base secretion, epithelial conductance and oxygen consumption for the frequently feeding diamondback water snake (Nerodia rhombifer) and the infrequently feeding Burmese python (Python molurus). Independent of body mass, Burmese pythons possess a significantly lower standard metabolic rate and respond to feeding with a much larger metabolic response compared with water snakes. While fasting, pythons cease gastric acid and intestinal base secretion, both of which are stimulated with feeding. In contrast, fasted water snakes secreted gastric acid and intestinal base at rates similar to those of digesting snakes. We observed no difference between fasted and fed individuals for either species in gastric or intestinal transepithelial potential and conductance, with the exception of a significantly greater gastric transepithelial potential for fed pythons at the start of titration. Water snakes experienced no significant change in gastric or intestinal metabolism with feeding. Fed pythons, in contrast, experienced a near-doubling of gastric metabolism and a tripling of intestinal metabolic rate. For fasted individuals, the metabolic rate of the stomach and small intestine was significantly lower for pythons than for water snakes. The fasting downregulation of digestive function for pythons is manifested in a depressed gastric and intestinal metabolism, which selectively serves to reduce basal metabolism and hence promote survival between infrequent meals. By maintaining elevated GI performance between meals, fasted water snakes incur the additional cost of tissue activity, which is expressed in a higher standard metabolic rate.

Original languageEnglish
Pages (from-to)185-196
Number of pages12
JournalJournal of Experimental Biology
Volume215
Issue number1
DOIs
StatePublished - Jan 1 2012

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Colubridae
Boidae
Python
snake
secretion
snakes
metabolism
stomach
Stomach
Acids
acids
acid
fasting
meals (menu)
Meals
Snakes
Fasting
Gastric Acid
water
gastric acid

Keywords

  • Digestion
  • Electrophysiology
  • Gastric acid
  • Intestinal base
  • Nerodia rhombifer
  • Postprandial
  • Python molurus
  • Reptile
  • Snake
  • Specific dynamic action
  • Tissue metabolism

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Ecology, Evolution, Behavior and Systematics
  • Molecular Biology
  • Physiology
  • Insect Science
  • Aquatic Science

Cite this

Selected regulation of gastrointestinal acid-base secretion and tissue metabolism for the diamondback water snake and Burmese python. / Secor, Stephen M.; Taylor, Josi R.; Grosell, Martin.

In: Journal of Experimental Biology, Vol. 215, No. 1, 01.01.2012, p. 185-196.

Research output: Contribution to journalArticle

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