title: N-terminal and C-terminal fragments of the hormone stanniocalcin show differential effects in eels.
abstract: The effects of an N-terminal, a C-terminal, and a mid-fragment of stanniocalcin, the primary hypocalcemic hormone in fish, on plasma total and free (ionic) calcium levels and whole animal calcium influx were tested in eels. Both the N- and the C-terminal fragments were hypocalcemic, causing 18 and 12% reduction in plasma calcium in stanniectomized eels, respectively. With both fragments the hypocalcemic action is transient. The hypocalcemia caused by the C-terminal fragment, although more rapid, is not as pronounced as the hypocalcemic action of the N-terminal fragment. Only the C-terminal fragment reduced calcium influx. The hypocalcemic activity of the C-terminal fragment then can be explained by its effect on calcium influx. The N-terminal fragment appears to function in a different manner. The mid-fragment has no effect on plasma calcium or calcium influx. The different parts of the hormone are concluded to have different effects.
authors.affiliation: Department of Animal Physiology, University of Nijmegen, The Netherlands.
authors.forename: P M
authors.initials: PM
authors.lastname: Verbost
authors.forename: J C
authors.initials: JC
authors.lastname: Fenwick
mesh_terms: D000811:Anguilla / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000097:blood / Q000493:pharmacokinetics*; D002121:Calcium Channel Blockers / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D006023:Glycoproteins / Q000378:metabolism / Q000494:pharmacology*; D006728:Hormones / Q000378:metabolism / Q000494:pharmacology*; D006996:Hypocalcemia / Q000378:metabolism; D017136:Ion Transport / Q000187:drug effects; D008297:Male; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D014337:Trout
chemical_list: D002121:Calcium Channel Blockers; D006023:Glycoproteins; D006728:Hormones; D010446:Peptide Fragments; C051795:teleocalcin; D002118:Calcium