Abstract
Organ culture is an in vitro method for investigating cellular mechanisms involved in upregulation of vasocontractile G-protein coupled receptors. We hypothesize that mitogen-activated-protein kinase (MEK) and/or extracellular-signal-regulated kinase (ERK) specific inhibitors will attenuate the G-protein coupled receptor expression following organ culture. Rat cerebral arteries were incubated 48 h in the presence of MEK/ERK specific inhibitors U0126, PD98059, SL327, or AG126 for different time periods. Contractile responses by activation of endothelin receptor type A and type B. serotonin receptor 5-FIT18, prostanoid TP receptor, and angiotensin II receptor type 1 and type 2 were investigated. Results were verified by measurement of mRNA with real time PCR and by protein immunohistochemistry. Organ culture induced transcriptional upregulation of endothelin ETB receptor and of serotonin 5-HTIB receptor on translational level and increased respective contractions. The prostanoid TP receptor mediated contraction curve was left-wards shifted by organ culture. Organ culture was associated with elevated pERK1/2 in the vascular smooth muscle cells: the MEK1/2 inhibitor U0126 attenuated the endothelin ETB receptor mediated contraction at post-translational level or by changing the receptor affinities. The serotonin 5-HT,B receptor and prostanoid TP receptor mediated contractions were abolished by U0126. Administration of U0126 6 h after start of incubation blocked the receptor upregulation. In conclusion, MEK specific inhibitor U0126 is a potent inhibitor of G-protein coupled receptor alteration seen during organ culture. Given the ability to inhibit G-protein coupled receptor alteration at the clinically relevant time-point 6 h post incubation makes it an attractive therapeutic agent for in vivo studies. (C) 2010 Elsevier By. All rights reserved.
Original language | English |
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Pages (from-to) | 128-137 |
Journal | European Journal of Pharmacology |
Volume | 644 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - 2010 |
Subject classification (UKÄ)
- Pharmacology and Toxicology
Free keywords
- MEK/ERK pathway
- U0126
- Cerebral arteries
- Organ culture
- G-protein coupled receptor upregulation
- Vascular smooth muscle cells