Hormonal regulation of lipid metabolism in developing coho salmon, Oncorhynchus kisutch
Lipid metabolism in juvenile coho salmon is characterized, and adaptive changes in lipid mobilization are described in relation to development and hormonal influences. The rates of lipogenesis and lipolysis were determined in selected tissues of juvenile salmon during the period of seawater preadaptive development (smoltification). Neutral lipid (sterol) and fatty acid synthesis in the liver and mesenteric fat was measured by tritium incorporation. Fatty acid synthesis in the liver and mesenteric fat decreased by 88% and 81%, respectively, between late February (parr) and early June (smolt). To assess the role of hormones in smoltification-associated lipid depletion, growth hormone, prolactin, thyroxin and cortisol were administered in vivo early in development (parr) to determine if any of these factors could initiate the metabolic responses normally seen later in development (smolt). Growth hormone stimulated lipid mobilization from coho salmon parr. Prolactin strongly stimulated lipid mobilization in coho parr. Thyroxin and cortisol also stimulated lipid mobilization for coho salmon parr. The direct effect of hormones was studied by in vitro pH-stat incubation of liver slices. These data suggest that norepinephrine stimulates fatty acid release via ..beta..-adrenergic pathways. Somatostatin and its partial analogue from the fish caudal neurosecretory system, urotensin II, also affect lipid mobilization. These results establish the presence of hormone-sensitive lipase in salmon liver and suggest that the regulation of lipid metabolism in salmon involves both long-acting and short-acting hormonal agents.
- Research Organization:
- California Univ., Berkeley (USA)
- OSTI ID:
- 6792085
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HORMONES
BIOCHEMISTRY
LIPIDS
BIOSYNTHESIS
METABOLISM
SEASONAL VARIATIONS
TRITIUM COMPOUNDS
ANIMAL GROWTH
CARBOXYLIC ACIDS
HYDROCORTISONE
IN VITRO
LIVER
LTH
SALMON
STH
THYROXINE
ADRENAL HORMONES
AMINO ACIDS
ANADROMOUS FISHES
ANIMALS
AQUATIC ORGANISMS
BODY
CHEMISTRY
CORTICOSTEROIDS
DIGESTIVE SYSTEM
FISHES
GLANDS
GLUCOCORTICOIDS
GONADOTROPINS
GROWTH
HYDROXY COMPOUNDS
KETONES
LABELLED COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PREGNANES
STEROID HORMONES
STEROIDS
SYNTHESIS
THYROID HORMONES
VARIATIONS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques