Anandamide can be metabolized by cyclooxygenase-2 to produce prostaglandin E(2) (PGE(2)) ethanolamide. The purpose of this study was to investigate the pharmacology of this novel compound. Radioligand binding experiments in membranes from human embryonic kidney cells transfected with PGE(2) receptor subtypes EP(1), EP(2), EP(3), and EP(4) revealed that PGE(2) ethanolamide has pK(i) values of 5.61 +/- 0.1, 6.33 +/- 0.01, 6.70 +/- 0.13, and 6.29 +/- 0.06, respectively, compared with 8.31 +/- 0.16, 9.03 +/- 0.04, 9.34 +/- 0.06, and 9.10 +/- 0.04 for PGE(2). PGE(2) inhibits electrically evoked contractions of the guinea pig vas deferens (EP(3) receptor-mediated), with a pEC(50) value of 9.09 +/- 0.06, compared with that of 7.38 +/- 0.09 for PGE(2) ethanolamide. In the guinea pig trachea, 100 nM PGE(2) and 1 microM PGE(2) ethanolamide produced contractions of 51.8 +/- 10.6 and 38.9 +/- 5.6% (of the histamine E(max)), respectively. The EP(1) receptor antagonist SC-51089 (10 microM) prevented the contractions induced by both compounds. In the presence of 10 microM 8-chlorodibenz[b,f][1,4]oxazepine-10(11H)-carboxylic acid, 2-[1-oxo-3-(4-pyridinyl)propyl]hydrazide, monohydrochloride (SC-51089), PGE(2) caused a concentration-related relaxation of histamine-induced contractions of this tissue (EP(2) receptor-mediated), the pEC(50) value being 8.29 +/- 0.17 compared with that of 7.11 +/- 0.18 for PGE(2) ethanolamide. In the rabbit jugular vein, PGE(2) induces relaxation (EP(4) receptor-mediated) with a pEC(50) of 9.35 +/- 0.25, compared with 7.05 +/- 0.4 for PGE(2) ethanolamide. In dorsal root ganglion neurons in culture, 3 microM PGE(2) ethanolamide evoked an increase in intracellular calcium concentration in 21% of small-diameter capsaicin-sensitive neurons. We conclude that this compound is pharmacologically active, however its physiological relevance has yet to be established.
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http://dx.doi.org/10.1124/jpet.301.3.900 | DOI Listing |
Protopanaxadiol (PPD) has potential immunomodulatory effects, but the underlying mechanism remains unclear. Here, we explored the potential roles of gut microbiota in the immunity regulation mechanisms of PPD using a cyclophosphamide (CTX)-induced immunosuppression mouse model. Our results showed that a medium dose of PPD (PPD-M, 50 mg/kg) effectively ameliorated the immunosuppression induced by CTX treatment by promoting bone marrow hematopoiesis, increasing the number of splenic T lymphocytes and regulating the secretion of serum immunoglobulins and cytokines.
View Article and Find Full Text PDFJ Pharmacol Exp Ther
July 2016
Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia
Recent studies have demonstrated that l-homocysteine (Hcys)-induced podocyte injury leading to glomerular damage or sclerosis is attributable to the activation of the nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome. Given the demonstrated anti-inflammatory effects of endocannabinoids, the present study was designed to test whether anandamide (AEA) or its metabolites diminish NLRP3 inflammasome activation and prevent podocyte injury and associated glomerular damage during hyperhomocysteinemia (hHcys). AEA (100 μM) inhibited Hcys-induced NLRP3 inflammasome activation in cultured podocytes, as indicated by elevated caspase-1 activity and interleukin-1β levels, and attenuated podocyte dysfunction, as shown by reduced vascular endothelial growth factor production.
View Article and Find Full Text PDFBiochim Biophys Acta
November 2015
UCIBIO, REQUIMTE, Laboratory of Biochemistry, Biological Sciences Department, Faculty of Pharmacy, University of Porto, Portugal.
Recently, endocannabinoids have emerged as signalling mediators in reproduction. It is widely accepted that anandamide (AEA) levels must be tightly regulated, and that a disturbance in AEA levels may impact decidual stability and regression. We have previously characterized the endocannabinoid machinery in rat decidual tissue and reported the pro-apoptotic action of AEA on rat decidual cells.
View Article and Find Full Text PDFTrends Pharmacol Sci
June 2014
Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Avenue Emmanuel Mounier 72 (B1.72.01), 1200 Bruxelles, Belgium. Electronic address:
Cyclooxygenase-2 (COX-2) is an enzyme that plays a key role in inflammatory processes. Classically, this enzyme is upregulated in inflammatory situations and is responsible for the generation of prostaglandins (PGs) from arachidonic acid (AA). One lesser-known property of COX-2 is its ability to metabolize the endocannabinoids, N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG).
View Article and Find Full Text PDFBiochim Biophys Acta
June 2013
Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, UK.
Background And Purpose: Prostaglandin ethanolamides or prostamides are naturally occurring neutral lipid derivatives of prostaglandins that have been shown to be synthesised in vivo following COX-facilitated oxygenation of arachidonoyl ethanolamine (anandamide). Although the actions of prostaglandins have been extensively studied, little is known about the physiological or pathophysiological effects of prostamides. Since prostaglandin E2 has potent immunosuppressive/immunomodulating actions, the aim of the present study was to determine whether the derivative, prostaglandin E2 ethanolamide (PGE2-EA), could modulate the production of the pro-inflammatory cytokine tumour necrosis factor-α in human blood and human monocytic cells and indicate whether this action involved the same receptor systems/signals as PGE2.
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