Associated alterations of striatal dopamine D2/D3 receptor and transporter binding in drug-naive patients with schizophrenia: a dual-isotope SPECT study.
OBJECTIVE
In vivo imaging studies have revealed deregulated presynaptic or postsynaptic function of the midbrain dopaminergic system in patients with schizophrenia. To further delineate the neuropathological involvement of the presynaptic and postsynaptic dopamine neurons in schizophrenia, the authors examined brain D(2)-family receptor and dopamine transporter binding simultaneously in patients with drug-naive schizophrenia using the dual-isotope single photon emission computed tomography (SPECT) imaging technique.


METHODS
Eleven patients with schizophrenia and 12 healthy comparison subjects were recruited. Striatal dopamine D(2)/D(3) receptor was measured with SPECT and [(123)I]iodobenzamide ([(123)I]IBZM), while dopamine transporter was measured with SPECT and [(99m)Tc]TRODAT-1.


RESULTS
Striatal D(2)/D(3) receptor and dopamine transporter binding were unaltered in these drug-naive patients with schizophrenia. Nonetheless, D(2)/D(3) receptor binding measures were positively correlated with dopamine transporter binding measures in these patients but not in the comparison subjects.


CONCLUSIONS
The associated presynaptic and postsynaptic disturbances of midbrain dopamine neurons could be clinically relevant in drug-naive patients with schizophrenia.
Department of Psychiatry, Institute of Behavioral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan 704, ROC. ykyang1960@ms81.url.com.tw
Yen Kuang
YK
Yang
Lung
L
Yu
Tzung Lieh
TL
Yeh
Nan Tsing
NT
Chiu
Po See
PS
Chen
I Hui
IH
Lee
D000293:Adolescent; D000328:Adult; D001549:Benzamides; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000502:physiology; D018492:Dopamine Antagonists; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000000981:diagnostic imaging / Q000378:metabolism; D015609:Organotechnetium Compounds; D011759:Pyrrolidines; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods / Q000706:statistics & numerical data; D014326:Tropanes
D001549:Benzamides; C493593:DRD3 protein, human; D018492:Dopamine Antagonists; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D015609:Organotechnetium Compounds; D011759:Pyrrolidines; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide; D004298:Dopamine