Aim To test the hypothesis that schizophrenia might be associated with alterations of the endogenous cannabinoid system in human blood. Results Blood from 20 healthy volunteers and 12 patients with schizophrenia, 5 of which both before and after a successful antipsychotic treatment, was analysed for: 1) the amounts of the endocannabinoid anandamide; 2) the levels of cannabinoid CB 1 and CB 2 receptor mRNAs, and 3) the levels of the mRNA encoding the enzyme fatty acid amide hydrolase (FAAH), responsible for anandamide degradation. The amounts of anandamide were significantly higher in the blood of patients with acute schizophrenia than in healthy volunteers (7.79 ± 0.50 vs. 2.58 ± 0.28 pmol/ml). Clinical remission was accompanied by a significant decrease of the levels of anandamide (3.88 ± 0.72 pmol/ml) and of the mRNA transcripts for CB 2 receptors and FAAH. Conclusion These findings indicate that endocannabinoid signalling might be altered during the acute phase of schizophrenia not only in the central nervous system but also in the blood. These changes might be related to the several immunological alterations described in schizophrenia.
Open Access Research Endocannabinoid signalling in the blood of patients with schizophrenia †1,2 †1,3 1,4 Nicola De Marchi , Luciano De Petrocellis* , Pierangelo Orlando , 5 1,6 1,6 Fabiana Daniele , Filomena Fezza and Vincenzo Di Marzo
1 2 Address: Endocannabinoid Research Group, Rochford Hospital, Rochford, UK, South Essex Partnership NHS Trust, Rochford Hospital, 3 4 Rochford, UK, National Research Council, Institute of Cybernetics, Via Campi Flegrei 34, Pozzuoli (NA), Italy, National Research Council, 5 6 Institute of Protein Biochemistry, Naples, Italy, Second University of Naples, Institute of Psychiatry, Naples, Italy and National Research Council, Institute of Biomolecular Chemistry, Via Campi Flegrei 34, Pozzuoli (NA), Italy Email: Nicola De Marchi Nicola.DeMarchi@southessextrst.nhs.uk; Luciano De Petrocellis* L.DePetrocellis@cib.na.cnr.it; Pierangelo Orlando orlando@dafne.ibpe.na.cnr.it; Fabiana Daniele fabianadaniele@libero.it; Filomena Fezza enia70@yahoo.it; Vincenzo Di Marzo vdimarzo@icmib.na.cnr.it * Corresponding author †Equal contributors
Abstract Aim:To test the hypothesis that schizophrenia might be associated with alterations of the endogenous cannabinoid system in human blood. Results:Blood from 20 healthy volunteers and 12 patients with schizophrenia, 5 of which both before and after a successful antipsychotic treatment, was analysed for: 1) the amounts of the endocannabinoid anandamide; 2) the levels of cannabinoid CB and CB receptor mRNAs, and 3) 1 2 the levels of the mRNA encoding the enzyme fatty acid amide hydrolase (FAAH), responsible for anandamide degradation. The amounts of anandamide were significantly higher in the blood of patients with acute schizophrenia than in healthy volunteers (7.79 ± 0.50 vs. 2.58 ± 0.28 pmol/ml). Clinical remission was accompanied by a significant decrease of the levels of anandamide (3.88 ± 0.72 pmol/ml) and of the mRNA transcripts for CB receptors and FAAH. 2 Conclusion:These findings indicate that endocannabinoid signalling might be altered during the acute phase of schizophrenia not only in the central nervous system but also in the blood. These changes might be related to the several immunological alterations described in schizophrenia.
Background The Endogenous Cannabinoid (EC) system comprises at least two cannabinoid receptors, the CB and CB recep 1 2 tors, a series of lipophilic endogenous ligands, the endo cannabinoids (ECs), and enzymes for EC biosynthesis and degradation [1]. Mounting evidence indicates that it is involved in the physiological modulation of many cru cial functions in both the peripheral and the central nerv
ous system [1]. It has been hypothesized that an alteration of EC neurotransmission could play a role in neurologi cal, psychiatric and immunological disorders [2,3]. In this context, it is possible that, along with other neurotrans mitter systems (i.e., dopaminergic, serotonergic), anoma lies of the ECs might take part in producing the clinical picture of schizophrenia. This hypothesis relies on the fol lowing considerations:
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