STEREOSELECTIVITY OF 8-OH-DPAT ENANTIOMERS AT CLONED HUMAN 5-HT1D RECEPTOR-SITES

The cAMP responses of (+/-)-8-hydroxy-2-(di-n-propylamino)tetralin (8- OH-DPAT) and its enantiomers were measured at cloned human 5-HT1D alph a and 5-HT1D beta receptors in transfected C6-glial cells. R(+)-8-OH-D PAT demonstrated potent intrinsic activity (EC(50) value: 30 nM) at 5- HT1D alpha receptor sites, its maximal effect being comparable to that of sumatriptan. Racemic 8-OH-DPAT and S(-)-8-OH-DPAT showed similar a gonist efficacy but were respectively 2 and 75 times less potent than R(+)-8-OH-DPAT. This differs from the lack of stereoselectivity of the 8-OH-DPAT enantiomers for 5-HT1A receptors.