Effectors of metabolic depression in an estivating pulmonate snail (Helix aspersa): whole animal and in vitro tissue studies

J Comp Physiol B. 1996;166(6):375-81. doi: 10.1007/BF02336920.

Abstract

We have examined metabolic depression in the land snail (Helix aspersa) during estivation, and have developed a tissue model of metabolic depression using an in vitro mantle preparation. The metabolic rate of H. aspersa is depressed by 84% in vivo within 4 weeks of onset of estivation, and this metabolic depression is accompanied by a decrease in haemolymph PO2 and pH, and an increase in haemolymph PCO2. The in vitro mantle preparation has a stable O2 consumption and energy charge, and an energy charge similar to that of mantle in vivo. The in vitro mantle is an O2-conforming tissue, with VO2 varying curvilinearly with PO2. Consequently, we have developed a mathematical method of calculating tissue VO2 at any PO2. These calculations show that under appropriate incubation conditions of pH and PO2, the mantle from estivating animals shows a stable in vitro metabolic depression of 48% compared to mantle from control snails. The extrinsic effects of PO2 and pH account for 70% of the total in vitro metabolic depression of mantle tissue; intrinsic effectors contribute a further 30%.

MeSH terms

  • Adenosine Diphosphate / metabolism
  • Adenosine Monophosphate / metabolism
  • Adenosine Triphosphate / metabolism
  • Analysis of Variance
  • Animals
  • Biotransformation
  • Helix, Snails / physiology*
  • Hemolymph / metabolism
  • Hemolymph / physiology*
  • Hydrogen-Ion Concentration
  • In Vitro Techniques
  • Models, Theoretical
  • Osmolar Concentration
  • Oxygen Consumption / physiology*
  • Partial Pressure
  • Spectrophotometry, Ultraviolet
  • Temperature
  • Tissue Preservation

Substances

  • Adenosine Monophosphate
  • Adenosine Diphosphate
  • Adenosine Triphosphate