Adrenomedullin-like immunoreactivity in the nervous system of the starfish Marthasterias glacialis

Abstract

The nervous system of the starfish Marthasterias glacialis was investigated immunocytochemically using an antiserum specific for adrenomedullin (AM), a new regulatory peptide. Immunoreactivity was only found in nerves of the basiepithelial plexus of cardiac and pyloric stomachs and pyloric caeca, while the radial nerve cords and the other digestive organs were negative. The strongest AM-like immunoreactivity was located in the current-producing areas of the cardiac stomach. The distribution of this peptide suggests different functions in echinoderms involving regulation of muscle movement and neurotransmission. The presence of an AM-like substance in echinoderms points to an early phylogenetic origin for this regulatory system.

Adrenomedullin regulates intestinal physiology and pathophysiology

“…However, the presence of AM in the digestive tract is not exclusive for mammals, or even vertebrates ( Fig. 1), Martínez et al [135] demonstrated the presence of an AM-like substance in the nervous system of the digestive tract of the starfish Marthasterias glacialis. This immunoreactivity was only found in nerves of the basiepithelial plexus of cardiac and pyloric stomachs and pyloric ceca, suggesting that AM could be involved in the regulation of contraction of the muscle cell layer of the digestive wall.…”

“…This immunoreactivity was only found in nerves of the basiepithelial plexus of cardiac and pyloric stomachs and pyloric ceca, suggesting that AM could be involved in the regulation of contraction of the muscle cell layer of the digestive wall. The presence of an AM-like immunoreactivity in an invertebrate suggests that AM has been largely conserved throughout evolution [135].…”

The Mammalian Peptide Adrenomedullin Acts as a Growth Factor in Tobacco Plants

“…The last intermediate before fully mature AM is Gly-extended AM (or Gly-AM), which usually lacks physiological activity (Martinez et al, 2006). AM homologs have been found in all vertebrates, from humans to fish (Martinez et al, 2006), and immunoreactive epitopes were detected in invertebrates such as echinoderms (Martinez et al, 1996). No apparent homology is found between AM and any of the described plant peptide hormones.…”

Multiple roles of adrenomedullin revealed by animal models

“…The newly identified adrenomedullin (AM) gene encodes for a potent 52-amino acid peptide vasodilator that is highly conserved from starfish to humans (Martinez et al, 1996), and is expressed in many tissues. Because of this, many biological functions have been ascribed to AM, and it is currently viewed as a multifunctional peptide hormone (reviewed by Hinson et al, 2000).…”