Neurotensin reduces the affinity of dopamine D2 receptors in membranes from post mortem human caudate-putamen.
The effects of neurotensin in vitro were investigated on the binding characteristics of N-[3H]propylnorapomorphine [( 3H]NPA) binding sites in crude membrane preparations from post mortem human caudate-putamen, obtained within 10 h after death from 3 patients without reported neurological or psychiatric diseases. Neurotensin (0.1-30 nM) was found to increase the KD value of [3H]NPA binding sites with a maximal increase of about 50% (420 +/- 45 pM) at 3 nM of neurotensin, without significantly affecting the Bmax value (123 +/- 20 pmol/g protein). These results indicate the existence of an intramembrane regulation by neurotensin receptors of D2 receptors in the human caudate-putamen.
von Euler
G
G
Department of Histology and Neurobiology, Karolinska Institutet, Stockholm, Sweden.
Mailleux
P
P
Vanderhaeghen
J J
JJ
Fuxe
K
K
D000368:Aged; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D009496:Neurotensin / Q000494:pharmacology*; D011180:Postmortem Changes; D011954:Receptors, Dopamine / Q000187:drug effects / Q000378:metabolism*; D017448:Receptors, Dopamine D2
D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D009496:Neurotensin