title: Sodium challenge does not support an acute gastrointestinal-renal natriuretic signaling axis in humans.
abstract: A gastrointestinal-renal natriuretic signaling axis has been proposed to regulate sodium excretion in response to acute sodium ingestion. Such an axis is thought to be regulated by a gastrointestinal sodium sensor coupled to the activation/release of a natriuretic signal and could have important clinical and scientific implications. Here we systematically tested for this putative axis and the potential involvement of the gastrointestinal-derived natriuretic prohormones prouroguanylin and proguanylin in 15 healthy volunteers. There was no difference in sodium excretion following equivalent oral or intravenous sodium loads during either high- or low-sodium diets. Furthermore, serum concentrations of prouroguanylin and proguanylin did not increase, did not differ following oral or intravenous sodium, and did not correlate with sodium excretion. Thus, our results do not support an acute gastrointestinal-renal natriuretic axis or a central role for prouroguanylin or proguanylin in humans. If such an axis does exist, it is not characterized by a significant difference in the pattern of sodium excretion following either an oral or intravenous sodium load.
authors.affiliation: Clinical Pharmacology Research Unit, Division of Clinical Pharmacology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida 33136, USA. rpreston@med.miami.edu
authors.forename: Richard A
authors.initials: RA
authors.lastname: Preston
authors.forename: David
authors.initials: D
authors.lastname: Afshartous
authors.forename: Leonard R
authors.initials: LR
authors.lastname: Forte
authors.forename: Rolando
authors.initials: R
authors.lastname: Rodco
authors.forename: Alberto B
authors.initials: AB
authors.lastname: Alonso
authors.forename: Dyal
authors.initials: D
authors.lastname: Garg
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Raij
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000450:Aldosterone / Q000097:blood; D001794:Blood Pressure; D003404:Creatinine / Q000097:blood; D004039:Diet, Sodium-Restricted; D005260:Female; D005431:Florida; D005768:Gastrointestinal Hormones / Q000097:blood; D041981:Gastrointestinal Tract / Q000378:metabolism*; D006801:Humans; D007262:Infusions, Intravenous; D007668:Kidney / Q000378:metabolism*; D008297:Male; D009318:Natriuresis; D011498:Protein Precursors / Q000097:blood; D015398:Signal Transduction; D012965:Sodium Chloride / Q000008:administration & dosage / Q000097:blood*; D017673:Sodium Chloride, Dietary / Q000097:blood; D013607:Tablets; D013997:Time Factors; D055815:Young Adult
chemical_list: D005768:Gastrointestinal Hormones; D011498:Protein Precursors; D017673:Sodium Chloride, Dietary; D013607:Tablets; C083435:preproguanylin; C097400:prouroguanylin; D012965:Sodium Chloride; D000450:Aldosterone; D003404:Creatinine