Membrane transport of anandamide through resealed human red blood cell membranes

Bojesen, Inge N.; Hansen, Harald S.

doi:10.1194/jlr.m400498-jlr200

Cited by 39 publications

(47 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Linear kinetics have also been observed in neuroblastoma, astrocytoma, and P19 embryonic carcinoma cells where uptake of total AEA occurred through rapid and unsaturable processes from 25 s to 45 s (19,22). A recent report examining the movement of AEA through a membrane (erythrocyte ghosts) lends further credence to this assertion (20). However, when we plotted uptake using unbound AEA, calculated from the K d for the dissociation of AEA from BSA (31), the resulting curves are saturating at 37°C (Fig.…”

Section: Discussionmentioning

confidence: 56%

“…14 -16). However, in platelets, neuroblastoma, astrocytoma, primary cortical neurons, and erythrocyte ghost membranes it has been suggested that uptake occurs by passive diffusion (13,(17)(18)(19)(20). Experimental variables such as incubation times, inclusion of bovine serum albumin (BSA) in the incubation medium and cell type differences may account for the disparities in results between laboratories (19, 21, 22).…”

Section: Arachidonoyl Ethanolamide (Aea)mentioning

confidence: 97%

“…For other cell types, it has been shown that incubation times longer than 1 min cannot isolate AEA uptake occurring at the plasma membrane from downstream processes, including FAAH activity and intracellular sequestration (11,12,19,20,49).…”

Section: Discussionmentioning

confidence: 99%

“…In order to study uptake in the absence of FAAH activity, cells were preincubated for 15 min with 100 nM CAY10400 prior to the addition of AEA. Unbound AEA concentrations were calculated based on the formula (20,31,37 3 H]HT and non-labeled 5-HT at a concentration range of 31.5-1000 nM. Cells were then washed three times with 750 l of ice-cold buffer, 2 ml of liquid scintillation mixture was added, and plates were placed on a shaker overnight.…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Anandamide Uptake Is Consistent with Rate-limited Diffusion and Is Regulated by the Degree of Its Hydrolysis by Fatty Acid Amide Hydrolase

Kaczocha

Hermann

Glaser

et al. 2006

Journal of Biological Chemistry

Self Cite

113

View full text Add to dashboard Cite

The uptake of arachidonoyl ethanolamide (anandamide, AEA) in rat basophilic leukemia cells (RBL-2H3) has been proposed to occur via a saturable transporter that is blocked by specific inhibitors. Measuring uptake at 25 s, when fatty acid amide hydrolase (FAAH) does not appreciably affect uptake, AEA accumulated via a nonsaturable mechanism at 37°C. Interestingly, saturation was observed when uptake was plotted using unbound AEA at 37°C. Such apparent saturation can be explained by rate-limited delivery of AEA through an unstirred water layer surrounding the cells (1). In support of this, we observed kinetics consistent with rate-limited diffusion at 0°C. Novel transport inhibitors have been synthesized that are either weak FAAH inhibitors or do not inhibit FAAH in vitro (e.g. UCM707, OMDM2, and AM1172). In the current study, none of these purported AEA transporter inhibitors affected uptake at 25 s. Longer incubation times illuminate downstream events that drive AEA uptake. Unlike the situation at 25 s, the efficacy of these inhibitors was unmasked at 5 min with appreciable inhibition of AEA accumulation correlating with partial inhibition of AEA hydrolysis. The uptake and hydrolysis profiles observed with UCM707, VDM11, OMDM2, and AM1172 mirrored two selective and potent FAAH inhibitors CAY10400 and URB597 (at low concentrations), indicating that weak inhibition of FAAH can have a pronounced effect upon AEA uptake. At 5 min, the putative transport inhibitors did not reduce AEA uptake in FAAH chemical knock-out cells. This strongly suggests that the target of UCM707, VDM11, OMDM2, and AM1172 is not a transporter at the plasma membrane but rather FAAH, or an uncharacterized intracellular component that delivers AEA to FAAH. This system is therefore unique among neuro/immune modulators because AEA, an uncharged hydrophobic molecule, diffuses into cells and partial inhibition of FAAH has a pronounced effect upon its uptake. Arachidonoyl ethanolamide (AEA)2 is a neuromodulatory lipid that belongs to a family of molecules collectively termed the endocannabinoids. Like ⌬ 9 -tetrahydracannabinol, many of the actions of AEA are mediated through the G-protein-coupled cannabinoid (CB 1 and CB 2 ) and vanilloid (TRPV1) receptors (2-7). AEA signaling is terminated by a rapid reuptake mechanism followed by its hydrolysis into arachidonic acid and ethanolamine primarily by the intracellular enzyme FAAH (8 -10). By metabolizing AEA, FAAH maintains an inward gradient that drives the continued cellular accumulation of AEA (11-13).There is some controversy regarding the processes mediating AEA uptake. It was widely accepted that AEA transport is a selective, saturable process of facilitated diffusion for which there are selective transport inhibitors (For review, see Refs. 14 -16). However, in platelets, neuroblastoma, astrocytoma, primary cortical neurons, and erythrocyte ghost membranes it has been suggested that uptake occurs by passive diffusion (13,(17)(18)(19)(20). Experimental variables such as incubation times, inclusion ...

show abstract

Section: Discussionmentioning

confidence: 56%

Section: Arachidonoyl Ethanolamide (Aea)mentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Anandamide Uptake Is Consistent with Rate-limited Diffusion and Is Regulated by the Degree of Its Hydrolysis by Fatty Acid Amide Hydrolase

Kaczocha

Hermann

Glaser

et al. 2006

Journal of Biological Chemistry

Self Cite

113

View full text Add to dashboard Cite

show abstract

“…Once inside cells, they freely diffuse through the cytosol to their sites of catabolism. In contrast, AEA is an uncharged lipid capable of traversing the bilayer unaided (10). Accordingly, several studies concluded that AEA uptake occurs by passive diffusion (10)(11)(12)(13)(14)(15), although facilitated diffusion and/or endocytosis have also been proposed (16)(17)(18)(19)(20).…”

mentioning

confidence: 99%

Identification of intracellular carriers for the endocannabinoid anandamide

Kaczocha¹,

Glaser

Deutsch³

2009

Proc. Natl. Acad. Sci. U.S.A.

311

332

View full text Add to dashboard Cite

The endocannabinoid anandamide (arachidonoyl ethanolamide, AEA) is an uncharged neuromodulatory lipid that, similar to many neurotransmitters, is inactivated through its cellular uptake and subsequent catabolism. AEA is hydrolyzed by fatty acid amide hydrolase (FAAH), an enzyme localized on the endoplasmic reticulum. In contrast to most neuromodulators, the hydrophilic cytosol poses a diffusional barrier for the efficient delivery of AEA to its site of catabolism. Therefore, AEA likely traverses the cytosol with the assistance of an intracellular carrier that increases its solubility and rate of diffusion. To study this process, AEA uptake and hydrolysis were examined in COS-7 cells expressing FAAH restricted to the endoplasmic reticulum, mitochondria, or the Golgi apparatus. AEA hydrolysis was detectable at the earliest measurable time point (

show abstract

Endocannabinoids

Hansen¹,

Petersen²,

Artmann³

et al. 2006

Eur. J. Lipid Sci. Technol.

Self Cite

View full text Add to dashboard Cite

EndocannabinoidsThe endocannabinoid system embraces a group of lipid molecules, enzymes and receptor proteins. This system appears to be involved in the modulation of neurotransmitter release thereby modifying learning and memory, in the regulation of food intake, and in the modulation of inflammation and pain and several other physiological/ pathophysiological conditions. Furthermore, naturally occurring structural analogues of one of the endocannabinoids also appear to have beneficial biological activity in animal models of pain and obesity, although these endogenous compounds cannot activate cannabinoid receptors. The intention of this short review is to give an updated overview of this very large field from a biochemical and pharmacological point of view.

show abstract

Membrane transport of anandamide through resealed human red blood cell membranes

Cited by 39 publications

References 42 publications

Anandamide Uptake Is Consistent with Rate-limited Diffusion and Is Regulated by the Degree of Its Hydrolysis by Fatty Acid Amide Hydrolase

Anandamide Uptake Is Consistent with Rate-limited Diffusion and Is Regulated by the Degree of Its Hydrolysis by Fatty Acid Amide Hydrolase

Identification of intracellular carriers for the endocannabinoid anandamide

Endocannabinoids

Contact Info

Product

Resources

About