Anandamide activity and degradation are regulated by early postnatal aging and follicle-stimulating hormone in mouse Sertoli cells.

Anandamide (AEA), a prominent member of the endogenous ligands of cannabinoid receptors (endocannabinoids), is known to adversely affect female fertility. However, a potential role of AEA in male reproductive functions is unknown. Here we report evidence that immature mouse Sertoli cells have the biochemical tools to bind and inactivate AEA, i.e. a functional type-2 cannabinoid receptor (CB2R), a selective AEA membrane transporter, and an AEA-degrading enzyme fatty acid amide hydrolase. We show that, unlike CB2R, the activity of AEA membrane transporter and the activity and expression of FAAH decrease, whereas the apoptosis-inducing activity of AEA increases with age during the neonatal period. We also show that FSH reduces the apoptotic potential of AEA, but not that of its nonhydrolyzable analog methanandamide. Concomitantly, FSH enhances FAAH activity in a manner dependent on mRNA transcription and protein synthesis and apparently involving cAMP. These data demonstrate that Sertoli cells partake in the peripheral endocannabinoid system, and that FSH reduces the apoptotic potential of AEA by activating FAAH. Taken together, it can be suggested that the endocannabinoid network plays a role in the hormonal regulation of male fertility.

Binding, degradation and apoptotic activity of stearoylethanolamide in rat C6 glioma cells.

Stearoylethanolamide (SEA) is present in human, rat and mouse brain in amounts comparable with those of the endocannabinoid anandamide (arachidonoylethanolamide; AEA). Yet, the biological activity of SEA has never been investigated. We synthesized unlabelled and radiolabelled SEA to investigate its binding, degradation and biological activity in rat C6 glioma cells. We report that SEA binds to a specific site distinct from known cannabinoid or vanilloid receptors, and that AEA and capsazepine partly (approx. 50%) antagonized this binding. Treatment of C6 cells with SEA inhibits cellular nitric oxide synthase and does not affect adenylate cyclase, whereas treatment with cannabinoid type 1 agonist 2-arachidonoylglycerol activates the former enzyme and inhibits the latter. C6 cells also have a specific SEA membrane transporter, which is inhibited by NO, and a fatty acid amide hydrolase capable of cleaving SEA. In these cells, SEA shows pro-apoptotic activity, due to elevation of intracellular calcium, activation of the arachidonate cascade and mitochondrial uncoupling. NO further enhances SEA-induced apoptosis. Moreover, the cannabinoid type 1 receptor-mediated decrease in cAMP induced by AEA in C6 cells is potentiated by SEA, suggesting that this compound also has an 'entourage' effect. Taken together, this study shows that SEA is an endocannabinoid-like compound which binds to and is transported by new components of the endocannabinoid system. It seems noteworthy that degradation and pro-apoptotic activity of SEA are regulated by NO in a way opposite to that reported for AEA.