Patterns of lipid storage and utilization reflect the special life histories of the animal group. Poikilothermic vertebrates (fish, amphibians, reptiles) have evolved a number of life history patterns (smoltification, metamorphosis, hibernation) which present problems for lipid storage regulation. A general theme among poikilotherms is to store lipids among several sites (mesenteric fat, liver, muscle) as opposed to a single depot type (adipose tissue) as in homeotherms; lipids are stored primarily as triacylglycerols, but various other lipid classes also are stored and constituent fatty acids tend to be more complex (longer chain, polyunsaturated). Lipid storage is influenced by de novo lipid synthesis and by lipid deposition from various plasma lipoproteins. Lipid accumulation generally occurs in most poikilotherms during periods of feeding when plasma insulin levels are elevated. Lipid mobilization is controlled by an intracellular lipase enzyme. Lipid depletion occurs during transitional and non-feeding periods and is especially apparent during salmonid smoltification and amphibian metamorphosis.
|Number of pages||14|
|Journal||Comparative Biochemistry and Physiology -- Part B: Biochemistry and|
|State||Published - Apr 1994|
- Lipid metabolism