To characterize further the α2-adrenoceptor subtypes in terms of their regulation, monolayers of cells expressing either the α2A (CHO-A2AR cells) or α2C (OK cells) subtype were preincubated with norepinephrine for various times and the extent of receptor down-regulation was assessed. Exposure to 30 μM norepinephrine caused a similar time course and extent of down-regulation (approximately 50%) in both cells lines. The extent of down-regulation caused by 0.3 μM norepinephrine in OK cells was similar to that with 30 μM norepinephrine in CHO-A2AR cells, although the time course was somewhat slower. Reversal of the down-regulation of the α2-adrenoceptor caused by 30 μM norepinephrine was more rapid in the CHO-A2AR than in the OK cell. With 0.3 μM norepinephrine, reversal of down-regulation of the α2-adrenoceptor in the OK cell was slightly faster than that of the CHO-A2AR cell with 30 μM norepinephrine. These data indicate that although norepinephrine is more potent in causing down-regulation of the α2C (OK cells) as compared to the α2A subtype (CHO-A2AR cells), the time courses for down-regulation and its reversal are similar for the two subtypes.
|Original language||English (US)|
|Number of pages||5|
|Journal||European Journal of Pharmacology: Molecular Pharmacology|
|State||Published - Jan 15 1993|
- Kidney cells (opossum)
- Transfected CHO cells
ASJC Scopus subject areas