Calcium is an equipotent stimulator of stanniocalcin secretion in freshwater and seawater salmon.

Stanniocalcin (STC) is a calcium- and phosphate-regulating hormone produced by the corpuscles of Stannius in fishes. A rise in ion calcium (Ca2+) levels is the principal stimulus for secretion, and the hormone acts on the gills, gut, and kidneys to restore normocalcemia. The STC-producing cells in marine fishes are metabolically more active and secrete more hormone than those in freshwater fishes, which has been attributed to the higher calcium content of seawater placing a greater burden on the organ systems governing Ca2+ homeostasis.

The gill calcium transport cycle in rainbow trout is correlated with plasma levels of bioactive, not immunoreactive, stanniocalcin.

Stanniocalcin (STC) is an inhibitor of gill Ca2+ transport that is produced by the corpuscles of Stannius, endocrine glands in bony fish. In young rainbow trout (Oncorhynchus mykiss), there are cyclical changes in the rate of gill Ca2+ transport, with alternating phases of accelerated and reduced uptake every 14 days. Previous studies by our laboratory have established that the responsiveness of young trout to the inhibitory effects of exogenous STC is dependent on this cycle.

Salmon stanniocalcin and bovine parathyroid hormone have dissimilar actions on mammalian bone.

Stanniocalcin (STC), a calcium-regulating glycoprotein hormone isolated from the corpuscles of Stannius of salmon, was tested for effects on bone and calcium metabolism in mammalian species (rats and mice). STC generally failed to alter serum calcium of parathyroidectomized rats at concentrations equimolar with effective concentrations of parathyroid hormone (PTH). STC did not increase cAMP in ROS 17/2.

Differential response of plasma prolactin to freshwater transfer of smolts and postsmolts of seawater-adapted coho salmon (Oncorhynchus kisutch).

Prolactin (PRL) was purified from chum salmon, Oncorhynchus keta, pituitary glands and was used to develop a homologous radioimmunoassay for the measurement of PRL from salmon. The plasma PRL response to freshwater (FW) transfer differed in seawater (SW)-adapted postsmolt (250 g) and smolts (15 g) of coho salmon. Postsmolts had a pronounced and prolonged elevation of plasma titers of PRL with hypercalcemia and stable plasma sodium levels.

Effects of synthetic peptide fragments of teleocalcin (hypocalcin) on calcium uptake in juvenile rainbow trout (Salmo gairdneri).

A rainbow trout fry bioassay based on 45Ca uptake was used to compare the effects of pure coho salmon teleocalcin (TC) and several synthetic peptide fragments of TC. Calcium uptake in the fry exhibited a cycle, with an amplitude variation of 3.3 to 48.