Parathyroid hormone-related protein regulates intestinal calcium transport in sea bream (Sparus auratus). | - CCMAR -

Journal Article

TítuloParathyroid hormone-related protein regulates intestinal calcium transport in sea bream (Sparus auratus).
Publication TypeJournal Article
AuthorsFuentes, J, Figueiredo, J, Power, DM, Canario, AVM
Year of Publication2006
JournalAm J Physiol Regul Integr Comp Physiol
Date Published2006 Nov
Palavras-chaveAnimals, Biological Transport, Calcium, Electrophysiology, Glycoproteins, Intestinal Mucosa, Intestines, Parathyroid Hormone-Related Protein, Sea Bream

Parathyroid hormone-related protein (PTHrP) is a factor associated with normal development and physiology of the nervous, cardiovascular, immune, reproductive, and musculoskeletal systems in higher vertebrates. It also stimulates whole body calcium uptake in sea bream (Sparus auratus) larvae with an estimated 60% coming from intestinal uptake in seawater. The present study investigated the role of PTHrP in the intestinal calcium transport in the sea bream in vitro. Unidirectional mucosal-to-serosal and serosal-to-mucosal 45Ca fluxes were measured in vitro in duodenum, hindgut, and rectum mounted in Ussing chambers. In symmetric conditions with the same saline, bathing apical and basolateral sides of the preparation addition of piscine PTHrP 1-34 (6 nM) to the serosal surface resulted in an increase in mucosal to serosal calcium fluxes in duodenum and hindgut and a reduction in serosal to mucosal in the rectum, indicating that different mechanisms are responsive to PTHrP along the intestine. In control asymmetric conditions, with serosal normal and mucosal bathed with a saline similar in composition to the intestinal fluid, there was a net increase in calcium uptake in all regions. The addition of 6 nM PTHrP 1-34 increased net calcium uptake two- to threefold in all regions. The stimulatory effect of PTHrP on net intestinal calcium absorption is consistent with a hypercalcemic role for the hormone. The results support the view that PTHrP, alone or in conjunction with recently identified PTH-like peptides, counteracts in vivo the hypocalcemic effects of stanniocalcin.


Alternate JournalAm. J. Physiol. Regul. Integr. Comp. Physiol.
PubMed ID16763076
CCMAR Authors