[en] The authors describe the routine method for preparing BZM and IBZM. ^*I-IBZM was prepared by the chloramine-T method and was purified by TLC. The radiochemical purity was better than 90%. (S)-(-)-¹²⁵I-IBZM can specificaly bound with rat striatal in vitro

[en] Using ³H-Bepridil as a radioligand and calmodulin (CaM, an intracellular calcium receptor) as a receptor, the characteristics of ³H-Bepridil binding to CaM from bovine brain were analyzed with equilibrium column binding technique. The ³H-Bepridil radioreceptor binding assay is also established. Binding of ³H-Bepridil to CaM specific, saturable and reversible only in the presence of calcium. Scatchard analysis revealed that K_D was 2.52 ± 0.44 μmol/1 (n = 5) and B_max was 13.95 ± 2.33 nmol/mg protein (n = 5). Hill analysis demonstrated that nH was was 0.96 ± 0.03 (n = 5). The intra-CV or inter-CV of this method was about 10% (n = 22), indicating good stability and reproducibility. The results of competitive inhibition experiments of newly synthesized compounds indicates that the affinity of all Bepridil analogs to CaM was similar with that of Bepridil

[en] The radioiodinated AIBZM was prepared, its binding characteristics with dopamine D₂ receptor was analyzed. The levorotatory precursor AIBZM was synthesized through two organic reactions and identified by ¹H NMR. AIBZM was radioiodinated to ¹²⁵I-AIBZM by the Chloramine-T method. Characteristics of ¹²⁵I-AIBZM binding to rat striatal membranes was analyzed by ligand binding assay. Labelling efficiency of ¹²⁵I-AIBZM was 90%, its radiochemical purity was 95%. Scatchard analysis of data revealed a single binding component with a dissociation constant of 3.41 x 10^-11 mol/L. ¹²⁵I-AIBZM was a dopamine D₂ receptor ligand with potent affinity. Whether radiolabeled AIBZM can be used as a receptor imaging agent should be worthy of further investigation

[en] ⁹⁹Tc^m-labeled dopamine D₂ receptor imaging agent ⁹⁹Tc^m-mEBZM was prepared and the biological evaluation was studied. ECD (L,L-ethyl cysteinate dimer) was conjugated with the benzamide derivative, which has high affinity with dopamine D₂ receptor, to yield ⁹⁹Tc^m-mEBZM. The biodistribution of ⁹⁹Tc^m-mEBZM in rats and mice was studied. The results showed that ⁹⁹Tc^m-mEBZM has higher stability in vitro and higher lipophilicity. The brain uptake of ⁹⁹Tc^m-mEBZM in mice is high (2.97%ID·g^-1 at 2 min), and the ratios of striatum/cerebellum both in rats and in mice were >1.55

[en] Objective: To explore the coronary artery showing capacity of coronary angiography by 16-detector row spiral CT with various methods under different heart rates. Methods: Forty subjects underwent coronary angiography by 16-detector row CT. Firsthand data were gathered by TOSHIBA Aqulition 16-detector row spiral CT and were reconstructed with Half and Segement methods through Vitrea II imaging workstation. Reconstructions were carried out with multi-position, multi-angle, 2D and 3D by SSD, VR, MPR, CVR, VE and blood vessel analysis. Results: All branches of coronary artery were showed clearly by both Half and Segement methods when heart rates were lower than 70 bpm. 70%-80% of R-R interval with Half method was more satisfactory. All branches of coronary artery showed clearly when heart rates were between 70 and 90 bpm. 50%-60% of R-R interval by segement method was better. All branches can be showed when heart rates were higher than 90 bpm. 50%-60% of R-R interval by segement method was more satisfactory. Right coronary artery was showed worse than left. Coronary artery showed unclearly by Half method. Conclusion: Under various heart rates, images of coronary artery trunks and branches can be gained satisfactorily with coronary angiography by 16-detector row spiral CT with different reconstruction methods,scan references and high concentration contrast medium. It is a unwounding and unreplaceable examination method for sieving, return visit of coronary heart disease. It has a broad prospect. (authors)

[en] Objective: To prepare and label the ¹²⁵I-β-CIT and study its biological distribution in animal. Methods: ¹²⁵I-β-CIT was prepared by the peracetic acid method and the chloramine-T method, and dopamine transporter (DAT) binding properties of ¹²⁵I-β-CIT were examined by in vivo biodistribution and inhibition studies in mice and whole body autoradiography in rats. Results: The radiolabelling yields of the peracetic acid and the chloramine-T methods were (53.4 +- 7.9)% and (88.4 +- 3.49)%, respectively. Following intravenous injection in mice, ¹²⁵I-β-CIT showed high accumulation in striatum, time to peak level uptake was 2 h after injection. GBR12909 significantly inhibited ¹²⁵I-β-CIT binding in striatum, while clomipramine significantly inhibited ¹²⁵I-β-CIT binding in hippocampus and cerebral cortex. The rat whole body autoradiography showed that the clearance of the tracer occurred through the hepatobiliary route. Conclusions: The results indicate β-CIT is an agent suitable for DAT imaging and can be used for the study of Parkinson's disease

[en] [¹²³I]AIBZM, (S)-5-[¹²³I]-Iodo-N-[(1-ethyl-2-pyrrolidinyl)] methyl-4-amine-2-methoxybenzamide is a derivative with high affinity for the D2 receptor. Labeling was achieved by the Iodogen^TM method. The in vivo affinity for the D2 receptor and the biological characteristics were performed in rats. The brain uptake of [¹²³I]AIBZM was significantly lower, however the striatum/cerebellum ratio (2h p.i.) was higher than that of [¹²³I]IBZM. Because of the high affinity and its possibly lower unspecific binding compared to [¹²³I]IBZM, [¹²³I]AIBZM may be a potential imaging agent for the D2 dopamine receptor

[en] Eleven (RS)-amino substituted benzamide compounds were synthesized. Radioligand competitive binding assay using ³H-sulpiride as the radioligand proved that these compounds were dopamine D₂ receptor antagonists. Determination of IC₅₀ showed that the affinity for D₂ receptor of the amino substituted and halogen-containing benzamide compounds were about ten times higher than that of sulpiride

[en] To observe the density changes of the dopamine transporters (DAT) and receptors in MPTP treated mouse model. Mice (n = 30) were given i.v. injections of 30 mg/kg MPTP for 1, 3, 5, 7 days respectively, and in vivo autoradiographic experiments were performed in the striatum using β-CIT for DAT, and IBZM for D₂R. Results showed that a significant decrease of ¹²⁵I-β-CIT binding was observed in the early phase, while no dramatic change occurred in ¹²⁵I-IBZM binding, but D₂R showed supersensitivity in the later stage. Thus combined imaging of DAT and D₂R may provide a valuable information for clinical and differential diagnosis of PD and assessment of the magnitude of degeneration of nigro-striatum

[en] Objective: To detect the activity of striatal dopamine transporters (DAT) in lesions of different order of severity of MPTP-induced mice model of parkinsonism by autoradiography with ¹²⁵I-β-CIT and to evaluate the clinical use of the β-CIT imaging for DAT detection. Methods: With regard to the different duration (days) of MPTP treatment, the C57BL mice were randomly divided into 5 groups, that is MPTP 1, 3, 5 and 7 day groups and control group treated with normal saline instead of MPTP. Two hours after intravenous administration with ¹²⁵I-β-CIT of 148 kBq, the brain tissue sections were imaged by autoradiography. The levels of dopamine (DA) and its metabolites were measured by high performance liquid chromatography and electrochemical detection (HPLC-ECD). The tyrosine hydroxylase (TH)-positive cells and fibres in the substantia nigra and striatum of the mice were observed by means of immunohistochemical technique. Results: As compared with control group, the radioactivity ratios of striatum to cortex (ST/CX) in 4 MPTP-treated groups were significantly reduced, by 20%, 42%, 45% and 52%, respectively. The concentrations of DA in the striatum of 4 MPTP-treated groups were remarkably decreased, by 47%, 75%, 95% and 95%, respectively. The gradual loss of DA neurons and fibres in the substantia nigra and striatum in 4 MPTP-treated groups was observed under microscopy. Conclusions: The functional abnormality of DAT paralleled the changes observed in neurochemistry and neuropathology studies in the lesions of different order of injury of the MPTP-treated mice. The β-CIT scanning for the activity of DAT may be useful for diagnosing PD at earlier phase and for monitoring the progression of the disease