File Archive - Fentanyl Documents - Active transport of fentanyl by the blood-brain barrier (1999)

News Groups Blog Forum Chat Video Audio Images Documents Wiki Home

		Drugs Forum > File Archive > Documents > VARIOUS DRUGS > Opium, Opiate & Opioids Documents > Fentanyl Documents
Active transport of fentanyl by the blood-brain barrier (1999)

Tags

FAQ n Rules

Mark Forums Read

Notices

Create a FREE account now to get access to more forums, more videos, more music, more documents, more images, more reviews, more news about drugs and much more functionality.
Start posting now, join our groups or create your unique profile.

links

Fentanyl Documents

Documents about China White, Sublimaze, Duragesic, Actiq, Fentora

New entries announced in forum Opium, Opiates & Opioids

Allowances: 4.88 Mbytes/0 bytes used

[RSS Feed]

Entries

Active transport of fentanyl by the blood-brain barrier (1999)

Left click: open entry/Right click: save entry

J Pharmacol Exp Ther. 1999 May;289(2):1084-9

Henthorn TK, Liu Y, Mahapatro M, Ng KY.

Previous studies have shown that uptake of the lipophilic opioid, fentanyl, by pulmonary endothelial cells occurs by both passive diffusion and carrier-mediated processes. To evaluate if the latter mechanism also exists in brain endothelium, transport of [3H]fentanyl was examined in primary cultured bovine brain microvessel endothelial cell (BBMEC) monolayers. Uptake of fentanyl appears to occur via a carrier-mediated process as uptake of [3H]fentanyl by BBMECs was significantly inhibited in a dose-dependent manner by unlabeled fentanyl. Fentanyl uptake was also significantly inhibited by either 4 degrees C or sodium azide/2-deoxyglucose, suggesting that carrier-mediated uptake of fentanyl was an active process. Fentanyl was also tested to determine whether it might be a substrate of the endogenous blood-brain barrier efflux transport system, P-glycoprotein (P-gp). Release of [3H]fentanyl or rhodamine 123, a known substrate of P-gp, previously loaded in the BBMECs was studied in the presence or absence of either fentanyl or verapamil, a known competitive inhibitor of P-gp. Both fentanyl (10 microM) and verapamil (100 microM) decreased release of rhodamine 123 from BBMECs, indicating that fentanyl is a substrate of P-gp in the BBMECs. This was further supported by the observation that uptake of [3H]fentanyl was significantly increased in Mg2+-free medium, a condition known to reduce P-gp activity. However, release of [3H]fentanyl was significantly increased when incubated with either unlabeled fentanyl or verapamil. These results suggest that the active P-gp-mediated extrusion of fentanyl in these cells is overshadowed by an active inward transport process, mediated by an as yet unidentified transporter. In addition, verapamil was shown to be a substrate of both P-gp and the fentanyl uptake transporter.

Discussion Thread

Category Fentanyl Documents

Submitted by Jatelka

27-01-2008
167.10 Kbytes Hits 23
Keywords: fentanyl pharmacology

Category

Forum Jump

Sitelinks:	Site Functions:
Homepage Wiki Documents Image Gallery Audio Video Forum Blog Groups News	Site Rules Frequently Asked Questions Register to Participate Did you forget your password? All Threads

All times are GMT +1. The time now is 21:04.