Effects of central and peripheral injections of apelin on fluid intake and cardiovascular parameters in rats

Physiol Behav. 2006 Sep 30;89(2):221-5. doi: 10.1016/j.physbeh.2006.06.006. Epub 2006 Jul 12.


Previous studies have indicated that apelin, a novel peptide suggested to have some actions related to angiotensin peptides, has either a dipsogenic or an antidipsogenic effect and either increases or decreases blood pressure. The present study attempts to provide replication or understanding of these disparate effects. Neither central (lateral or third cerebral ventricle) nor peripheral (intravenous) administration of apelin induced water intake in sated rats, nor did it decrease water intake in deprived rats. It also had no effect on sodium appetite. Peripherally injected apelin had a hypotensive action in anesthetized rats, but had no consistent effect in awake, unrestrained rats. We conclude that apelin does not have reliable or robust effects on fluid intake or blood pressure in Sprague-Dawley rats under normal conditions, but discuss the possibility for a role of apelin in fluid homeostasis in selected physiological states.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Apelin
  • Blood Pressure / physiology
  • Carrier Proteins / administration & dosage
  • Carrier Proteins / physiology*
  • Dose-Response Relationship, Drug
  • Drinking / physiology*
  • Injections, Intravenous
  • Injections, Intraventricular
  • Intercellular Signaling Peptides and Proteins
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Water-Electrolyte Balance / physiology*


  • Apelin
  • Apln protein, rat
  • Carrier Proteins
  • Intercellular Signaling Peptides and Proteins