Guerreiro, P. M.Fuentes, T.Power, DeborahIngleton, P. M.Flik, G.Canario, Adelino V. M.2014-05-172014-05-172001-09Guerreiro, P. M.; Fuentes, T.; Power, D. M.; Ingleton, P. M.; Flik, G.; Canario, A. V. M.Parathyroid hormone-related protein: a calcium regulatory factor in sea bream (Sparus aurata L.) larvae, American Journal of Physiology-Regulatory Integrative and Comparative Physiology, 281, 3, R855-R860, 2001.0363-6119AUT: ACA00258; DPO00386;http://hdl.handle.net/10400.1/3992Texto integral disponível através do editorThe effects of an N-terminal peptide (amino acids 1-38) of Fugu parathyroid hormone-related protein (PTHrP 1-38) on calcium regulation of larval sea bream were investigated in seawater (36 per thousand) and after transfer to dilute seawater (12 per thousand). Exposure to PTHrP 1-38 evoked a 1.5-fold increase in calcium influx in both full-strength and dilute seawater. Calcium influx in dilute seawater-adapted larvae was roughly one-half that observed in full-strength seawater controls. PTHrP 1-38 also reduced drinking of fish in seawater but, at all concentrations tested, was without effect in dilute seawater. The amount of water imbibed was 55% lower in dilute seawater than in seawater. PTHrP 1-38 exposure affected the calcium influx route: the main contribution of calcium uptake shifted from intestinal absorption to extraintestinal uptake, probably by the induction of a dose-dependent increase in branchial (active) transport. Moreover, seawater-adapted fish exposed to 1 nM and 10 mM PTHrP 1-38 experienced a 2.5-fold reduction in overall calcium efflux. Overall, the calciotropic action of PTHrP 1-38 resulted in a dose-dependent increase in net calcium balance.engHormoneN-terminalCalcium regulationjournal article2014-05-13