Downregulation of Cellular Metabolism During Environmental Stress: Mechanisms an

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Annu Rev Physiol. 1996;58:539-63. Related Articles, Links

Downregulation of cellular metabolism during environmental stress:

mechanisms and implications.

Hand SC, Hardewig I.

Department of EPO Biology, University of Colorado, Boulder 80309-

0334, USA.

Survival time of organisms during exposure to environmental stresses

that limit energy availability is, in general, directly related to

the degree of metabolic depression achieved. The energetic cost

savings realized by the organism is a consequence primarily of the

ability to depress ion pumping activities of cells, macromolecular

synthesis, and macromolecular turnover. Evidence supporting the

concept of channel arrest-the reduction in ion leakage across cell

membranes during hypometabolic states-has highlighted the energetic

benefits of limiting ATP turnover related to cellular ion

homeostasis. Depression of protein synthesis results in substantial

bioenergetic savings. However, when protein synthesis is arrested,

the preservation of macromolecules becomes increasingly important as

the duration of quiescence is extended because the cellular capacity

for replenishing these components is reduced. It is likely that the

rate of macromolecular degradation is a key feature that sets the

upper time limit for survival during chronic environmental stress.

Publication Types:

Review

PMID: 8815808 [PubMed - indexed for MEDLINE]