The distribution and physiological effects of three evolutionarily and sequence-related neuropeptides in Rhodnius prolixus: Adipokinetic hormone, corazonin and adipokinetic hormone/corazonin-related peptide

Gen Comp Endocrinol. 2014 Jan 1:195:1-8. doi: 10.1016/j.ygcen.2013.10.012. Epub 2013 Oct 31.


We have examined the distribution and physiological effects of three evolutionarily and sequence-related neuropeptides in Rhodnius prolixus. These neuropeptides, adipokinetic hormone (RhoprAKH), corazonin (CRZ) and adipokinetic hormone/corazonin-related peptide (RhoprACP) are present in distinct, non-overlapping neuronal subsets in the central nervous system (CNS), as determined by immunohistochemistry. Corazonin-like immunoreactive cell bodies are present in the brain and ventral nerve cord, whereas ACP-like immunoreactive cell bodies are only present in the brain, and AKH-like immunoreactive cell bodies only present in the corpus cardiacum (CC). The immunoreactivity to ACP, CRZ and AKH in R. prolixus suggests that ACP and CRZ are released within the CNS, and that CRZ and AKH are released as neurohormones from the CC. Injection of RhoprAKH into adult males elevated haemolymph lipid levels, but injection of CRZ or RhoprACP failed to have any effect on haemolymph lipid levels. Corazonin stimulated an increase in heart-beat frequency in vitro, but RhoprAKH and RhoprACP failed to do so. Thus, although all three neuropeptides share sequence similarity, the AKH and CRZ receptors only respond to their own ligand.

Keywords: Cardioaccelerator; Immunohistochemistry; Insect; Lipid mobilization; Neuropeptide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Central Nervous System / drug effects
  • Central Nervous System / metabolism
  • Evolution, Molecular*
  • Heart Rate / drug effects
  • Hemolymph / drug effects
  • Hemolymph / metabolism
  • Immunoenzyme Techniques
  • Insect Hormones / pharmacology*
  • Insect Proteins / metabolism*
  • Lipid Metabolism / drug effects
  • Muscle Contraction / drug effects
  • Neuropeptides / metabolism*
  • Neurosecretory Systems / drug effects
  • Neurosecretory Systems / metabolism
  • Neurotransmitter Agents / pharmacology*
  • Oligopeptides / pharmacology*
  • Peptide Fragments / pharmacology*
  • Pyrrolidonecarboxylic Acid / analogs & derivatives*
  • Pyrrolidonecarboxylic Acid / pharmacology
  • Rhodnius
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization


  • Insect Hormones
  • Insect Proteins
  • Neuropeptides
  • Neurotransmitter Agents
  • Oligopeptides
  • Peptide Fragments
  • adipokinetic hormone
  • corazonin protein, insect
  • Pyrrolidonecarboxylic Acid