Isolation and characterization of a leech neuropeptide in rat brains: coupling to nitric oxide release in leech, rat and human tissues.
The osmoregulator peptide (leech osmoregulatory factor, LORF; IPEPYVWD) was first found in the leech central nervous system (CNS). Given the fact that certain peptides can be found in mammals and invertebrates, e.g., opioid, we examined rat brains to determine if LORF was present. This peptide was found and isolated by successive reversed-phase HPLC purification steps and characterized by electrospray mass spectrometry measurement. It was sequenced by Edman degradation and quantified in different tissues by ELISA. Our results demonstrate the presence of LORF in the hypothalamus, thalamus, and striatum (6 pmol/mg of protein extract) and in other brain areas at lower levels. This octapeptide is also present in the rat duodenum and liver (10 to 14 pmol/mg) and at lower levels in heart, lung, pancreas and caudal spinal cord (< 5 pmol/mg). The testes, adrenals and kidneys have the lowest levels of all the tissues examined (ca. 0.5 pmol/mg of protein). Furthermore, we also demonstrate that LORF is coupled to nitric oxide (NO) release in leech CNS, rat hypothalamus and human saphenous vein in a manner which is inhibited by a nitric oxide synthase inhibitor as well as an antibody directed toward LORF. The study demonstrates that LORF, and its function in relation to NO release, has been conserved over more than 400 million years of evolution.
Salzet
M
M
Centre de Biologie Cellulaire, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France. salzet@pop.univ-lille1.fr
Salzet
B
B
Sáutière
P
P
Lésage
J
J
Beauvillain
J C
JC
Bilfinger
T V
TV
Rialas
C
C
Bjenning
C
C
Stefano
G B
GB
D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D019143:Evolution, Molecular; D017952:Ganglia, Invertebrate / Q000737:chemistry; D006801:Humans; D007865:Leeches / Q000502:physiology*; D008297:Male; D013058:Mass Spectrometry; D009206:Myocardium / Q000737:chemistry; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000302:isolation & purification* / Q000502:physiology; D009479:Neuropeptides / Q000032:analysis / Q000302:isolation & purification* / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009842:Oligopeptides / Q000032:analysis / Q000302:isolation & purification* / Q000502:physiology; D009928:Organ Specificity; D051381:Rats / Q000502:physiology*; D017208:Rats, Wistar; D012501:Saphenous Vein / Q000737:chemistry / Q000378:metabolism; D013045:Species Specificity; D013116:Spinal Cord / Q000737:chemistry / Q000378:metabolism; D013737:Testis / Q000737:chemistry; D014781:Viscera / Q000737:chemistry
D004791:Enzyme Inhibitors; C099554:LORF protein, Erpobdella octoculata; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D009842:Oligopeptides; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase