Evidence for an endocannabinoid system in the central nervous system of the leech Hirudo medicinalis
Molecular Brain Research. 2001-03-01; 87(2): 145-159
DOI: 10.1016/S0169-328X(00)00290-4
Read on PubMed
1. Brain Res Mol Brain Res. 2001 Mar 5;87(2):145-59. doi:
10.1016/s0169-328x(00)00290-4.
Evidence for an endocannabinoid system in the central nervous system of the
leech Hirudo medicinalis.
Matias I(1), Bisogno T, Melck D, Vandenbulcke F, Verger-Bocquet M, De
Petrocellis L, Sergheraert C, Breton C, Di Marzo V, Salzet M.
Author information:
(1)Laboratoire d’Endocrinologie et immunité des Annélides UPRES-A CNRS 8017,
SN3-USTL, 59655 Villeneuve d’Ascq, France.
In invertebrates, like Hydra and sea urchins, evidence for a functional
cannabinoid system was described. The partial characterization of a putative CB1
cannabinoid receptor in the leech Hirudo medicinalis led us to investigate the
presence of a complete endogenous cannabinoid system in this organism. By using
gas chromatography-mass spectrometry, we demonstrate the presence of the
endocannabinoids anandamide (N-arachidonoylethanolamine, 21.5+/-0.7 pmol/g) and
2-arachidonoyl-glycerol (147.4+/-42.7 pmol/g), and of the biosynthetic precursor
of anandamide, N-arachidonylphosphatidyl-ethanolamine (16.5+/-3.3 pmol/g), in
the leech central nervous system (CNS). Anandamide-related molecules such as
N-palmitoylethanolamine (32.4+/-1.6 pmol/g) and N-linolenoylethanolamine (5.8
pmol/g) were also detected. We also found an anandamide amidase activity in the
leech CNS cytosolic fraction with a maximal activity at pH 7 and little
sensitivity to typical fatty acid amide hydrolase (FAAH) inhibitors. Using an
antiserum directed against the amidase signature sequence, we focused on the
identification and the localization of the leech amidase. Firstly, leech nervous
system protein extract was subjected to Western blot analysis, which showed
three immunoreactive bands at ca. approximately 42, approximately 46 and
approximately 66 kDa. The former and latter bands were very faint and were also
detected in whole homogenates from the coelenterate Hydra vulgaris, where the
presence of CB1-like receptors, endocannabinoids and a FAAH-like activity was
reported previously. Secondly, amidase immunocytochemical detection revealed
numerous immunoreactive neurons in the CNS of three species of leeches. In
addition, we observed that leech amidase-like immunoreactivity matches to a
certain extent with CB1-like immunoreactivity. Finally, we also found that
stimulation by anandamide of this receptor leads, as in mammals, to inhibition
of cAMP formation, although this effect appeared to be occurring through the
previously described anandamide-induced and CB1-mediated activation of nitric
oxide release. Taken together, these results suggest the existence of a complete
and functional cannabinoid system in leeches.
DOI: 10.1016/s0169-328x(00)00290-4
PMID: 11245916 [Indexed for MEDLINE]