Gastrointestinal osmoreceptors and renal sodium excretion in humans

Autor: Morten H. Bestle, Peter Bie, Thomas Ulrik Skram Jensen, Lars Juel Andersen
Rok vydání: 2000
Předmět:
Zdroj: Andersen, L J, Jensen, T U, Bestle, M H & Bie, P 2000, ' Gastrointestinal osmoreceptors and renal sodium excretion in humans ', American Journal of Physiology: Regulatory, Integrative and Comparative Physiology . https://doi.org/10.1152/ajpregu.2000.278.2.r287
ISSN: 0363-6119
DOI: 10.1152/ajpregu.2000.278.2.r287
Popis: The hypothesis that natriuresis can be induced by stimulation of gastrointestinal osmoreceptors was tested in eight supine subjects on constant sodium intake (150 mmol NaCl/day). A sodium load equivalent to the amount contained in 10% of measured extracellular volume was administered by a nasogastric tube as isotonic or hypertonic saline (850 mM). In additional experiments, salt loading was replaced by oral water loading (3.5% of total body water). Plasma sodium concentration increased after hypertonic saline (+3.1 +/- 0.7 mM), decreased after water loading (-3.8 +/- 0.8 mM), and remained unchanged after isotonic saline. Oncotic pressure decreased by 9.4 +/- 1.2, 3.7 +/- 1.2, and 10.7 +/- 1.3%, respectively. Isotonic saline induced an increase in renal sodium excretion (104 +/- 15 to 406 +/- 39 micromol/min) that was larger than seen with hypertonic saline (85 +/- 15 to 325 +/- 39 micromol/min) and water loading (88 +/- 11 to 304 +/- 28 micromol/min). Plasma ANG II decreased to 22 +/- 6, 35 +/- 6, and 47 +/- 5% of baseline after isotonic saline, hypertonic saline, and water loading, respectively. Plasma atrial natriuretic peptide (ANP) concentrations and urinary excretion rates of endothelin-1 were unchanged. In conclusion, stimulation of osmoreceptors by intragastric infusion of hypertonic saline is not an important natriuretic stimulus in sodium-replete subjects. The natriuresis after intragastric salt loading was independent of ANP but can be explained by inhibition of the renin-angiotensin system.
Databáze: OpenAIRE