Regional CNS densities of monoamine receptors in alcohol-naive alcohol-preferring P and -nonpreferring NP rats.
The densities of subtypes of serotonin (5-HT) and dopamine (DA) receptors were determined in the CNS of alcohol-naive alcohol-preferring P and -nonpreferring NP lines of rats. Autoradiography studies were undertaken to measure the densities of 5-HT1B sites labelled with 100 pM [125I](-)-iodocyanopindolol, 5-HT3 sites labelled with 2 nM [3H]LY 278584, and D1 sites labelled with 1 nM[3H]SCH 23390. Membrane binding, using tissue combined from the olfactory bulb, olfactory tubercle, and nucleus accumbens, was carried out to determine Kd and B max values for the binding of 0.25-8.0 nM[3H]7-OH DPAT to D3 sites. Among the 48 regions measured for differences in 5-HT1B recognition sites, statistically significant differences (p < 0.05) were found only in the cingulate and retrosplenial cortices, in the lateral and medial septum, and in the lateral nucleus of the amygdala, with lower values being found in the P than the NP line. There were no significant differences in the regional CNS densities of D1 or 5-HT3 sites between the P and NP lines. There were also no differences between the rat lines in the Kd or Bmax values for [3H]7-OH DPAT binding to D3 sites. The lower densities of 5-HT1B sites in the CNS of the P compared to the NP rats may be a result of reduced numbers of 5-HT1B presynaptic autoreceptors as well as postsynaptic receptors in the P line. The observation that there are no differences in the amount of radioligand binding to D1, 5-HT3, and D3 sites between the P and NP lines suggests that the disparate alcohol drinking behaviors of these two lines is not associated with an innate alteration in the densities of these receptor subtypes.
McBride
W J
WJ
Department of Psychiatry, Indiana University School of Medicine, Indianapolis, USA.
Chernet
E
E
Russell
R N
RN
Wong
D T
DT
Guan
X M
XM
Lumeng
L
L
Li
T K
TK
D000818:Animals; D001345:Autoradiography; D001552:Benzazepines / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D018491:Dopamine Agonists / Q000378:metabolism; D000431:Ethanol / Q000008:administration & dosage*; D007191:Indazoles / Q000378:metabolism; D020120:Iodocyanopindolol; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism; D009830:Olfactory Bulb / Q000378:metabolism; D009833:Olfactory Pathways / Q000378:metabolism; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D051381:Rats; D017982:Receptors, Biogenic Amine / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D050637:Receptors, Dopamine D3; D011985:Receptors, Serotonin / Q000378:metabolism; D012702:Serotonin Antagonists / Q000378:metabolism; D013764:Tetrahydronaphthalenes / Q000378:metabolism; D014326:Tropanes / Q000378:metabolism
D001552:Benzazepines; D018491:Dopamine Agonists; C493595:Drd3 protein, rat; D007191:Indazoles; D017982:Receptors, Biogenic Amine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D013764:Tetrahydronaphthalenes; D014326:Tropanes; C061531:LY 278584; D000431:Ethanol; D020120:Iodocyanopindolol; D010869:Pindolol; C031349:7-hydroxy-2-N,N-dipropylaminotetralin