[en] The Pharmacokinetics local model for studying kinetic action of pharmaceuticals in the specific part of the body is established on the basis of the compartment model. A series of formulae is deduced, and with them the pharmacokinetic equation and several important parameters can be obtained. The local model successfully expanded the area of pharmacokinetics from the compartment model, which is mainly dealing with kinetic action of pharmaceuticals in blood, to the local model, which can study kinetic action of pharmaceuticals in any organ, tissue or fluid

[en] Human gastric inhibitory polypeptide (GIP) was labelled with the conjunction method. The results showed that the conjunction method succeeds in protecting the immunoactivity of human GIP. The ¹²⁵I-GIP was able to combine with its GIP antibody specifically. The binding rate was 50% at an antiserum dilution of 1.3 x 10⁴

[en] Objectives: The in vivo binding analysis of vesicular monoamine transporter type 2 (VMAT2) to radioligand has provided a means of investigating related disorders. Anesthesia is often inevitable when the investigations are performed in animals. In the present study, we tested effects of four commonly-used anesthetics: isoflurane, pentobarbital, chloral hydrate and ketamine, on in vivo VMAT2 binding to "1"8F-FP-(+)-DTBZ, a specific VMAT2 radioligand, in rat brain. Methods: The transient equilibrium time window for in vivo binding of "1"8F-FP-(+)-DTBZ after a bolus injection was firstly determined. The brain biodistribution studies under anesthetized and awake rats were then performed at the equilibrium time. Standard uptake values (SUVs) of the interest brain regions: the striatum (ST), hippocampus (HP), cortex (CX) and cerebellum (CB) were obtained; and ratios of tissue to cerebellum were calculated. Results: Isoflurane and pentobarbital did not alter distribution of "1"8F-FP-(+)-DTBZ in the brain relative to the awake group; neither SUVs nor ratios of ST/CB and HP/CB were altered significantly. Chloral hydrate significantly increased SUVs of all the brain regions, but did not significantly alter ratios of ST/CB and HP/CB. Ketamine significantly increased SUVs of the striatum, hippocampus and cortex, and insignificantly increased the SUV of the cerebellum; consequently, ketamine significantly increased ratios of ST/CB and HP/CB. Conclusions: It is concluded that in vivo VMAT2 binding to "1"8F-FP-(+)-DTBZ are not altered by isoflurane and pentobarbital, but altered by chloral hydrate and ketamine. Isoflurane and pentobarbital may be promising anesthetic compounds for investigating in vivo VMAT2 binding. Further studies are warranted to investigate the interactions of anesthetics with VMAT2 binding potential with in vivo PET studies.

[en] Rate constants are important pharmacokinetic parameters and very useful in study of radiopharmaceuticals, nuclide therapy and internal radiation. In the situation of small number of compartments, solution of rate constants is not too difficult. But with increasing compartment number, the calculation is tending to more complex, which makes solving rate constants very difficult. Therefore, according to a general principle a series of formulae is established to simplify the process of solving rate constants

[en] Solid phase exchange radioiodination method was used to label the compound. Pharmacokinetics was studied in rats and the data were dealt with by computer. The results indicate that the compound would be a potential myocardial imaging agent

[en] The pharmacokinetics local model was used to evaluate renal function. Some typical kinds of renal function cases, normal or disorder, were selected to be imaged with SPECT and those data measured were treated by the pharmacokinetics local model computer program (PLM). The results indicated that parameters, including peak value, peak time, inflexion time, half-excretion time, and kinetic equation played an important role in judging renal function. The fact confirms that local model is very useful in evaluating renal function

[en] Tissue plasminogen activator (tPA), due to its stability in acidic solution, could be conveniently labeled with ^99mTc by using stannous chloride method. More than 90% of biochemical activity was remained after the process of labeling and separation. The stability of ^99mTc-tPA was studied at different time and different pH values, respectively. The study indicates that ^99mTc-tPA would be a potential imaging agent for thrombus and tumor

[en] PLAP was isolated and purified from human placenta and the antiserum was obtained by immunizing the rabbits. A radioimmunoassay of PLAP (PLAP RIA) was established by labelling the antigen using the chloramine-T method. Its sensitivity was 1.54 μg/L, the recovery rate was between 96.7% and 105.2%, the intra- and inter-assay CV were 8.94% and 9.43%, respectively, the antiserum provided a linear response from 2 to 1000 μg/L. The assay has no cross-reactivity with liver AP. Serum level of PLAP were measured by PLAP RIA in 649 cases of normal pregnancy and 164 cases of high-risk pregnancy. The results indicated that the PLAP level increased proportionally with the advance of gestational age (r = 0.9843). In 33 cases of pregnancy induced hypertension and 21 cases of intrauterine fetal growth retardation, the PLAP were at significantly low level. In 7 cases of neonatal asphyxia and 26 cases of fetal distress, the PLAP level in the mother's serum were also low. In 53 cases of intrahepatic cholestasis of pregnancy, the PLAP level were similar to those of normal pregnancy. This study illustrated that PLAP RIA can play an important role in evaluation of placental function and fetal prognosis for cases of high-risk pregnancy

[en] The purpose is to investigate the characteristics of APRPGY peptide labeled with radioiodine homing to tumor angiogenesis. The preparation of radioiodinated APRPGY was carried out by Ch-T method. Radiochemical purity was determined by the paper chromatographic system. Biodistribution studies were accomplished using wound healing model and tumor bearing model ICR mice. At 5, 10, 30, 60, 120 and 240 min after radiopharmaceutical administration (174 kBq/200 μL of ¹³¹I-APRPGY), the animals were sacrificed. Blood samples and other interested tissues were collected, weighted and counted (n=6 animals each time). The percent injected dose per gram of organ (%ID/g) and the ratio of tumor/muscle for each animal were calculated. The radiochemical purity of the ¹³¹I-APRPGY was above 95%. The biodistribution of the radiolabeled peptide showed higher levels in both blood and kidneys than in other tissues. In all other organs, the radioactivity was rapidly excreted mainly by kidneys. The accumulation of radioactivity in the tumor was 6.7%ID/g at 10 min and decreased within 240 min to 2.1 %ID/g. The ratios of tumor/muscle of ¹³¹I-APRPGY were 2.1, 6.2, 3.3, 3.5 and 3.2 at 5, 10, 60, 120 and 240 min, respectively. In would healing model, the radios of would-healing tissue/muscle were 0.8, 1.3, 1.8, 1.9 and 1.4 at 10, 30, 60, 120 and 240 min, respectively. The high specific tumor uptake and predominantly renal excretion make ¹³¹I-APRPGY a potential candidate for tumor angiogenesis imaging. This peptide is therefore worthy of further investigation. (authors)

[en] Objective: To study the impact of all-trans-retinoic acid (ATRA) on the expression of sodium/iodide symporter (NIS) mRNA and the level of radioiodine uptake in thyroid cancer cell lines (FTC-133, K1, 8505C) in vitro. Methods: The expression level of NIS mRNA was determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The rate of radioiodine uptake was determined using γ-counter. Results: ATRA up-regulated the expression level of NIS mRNA with the concentration from 10^-7 to 10^-4 mol/L in FTC-133 and 10^-6 to 10^-4 mol/L in K1 cell lines, but not in 8505C cell line. ATRA increased the rate of radioiodine uptake in both FTC-133 and K1 cell lines. Conclusion: ATRA can up-regulate the expression level of NIS mRNA and increase the rate of radioiodine uptake in FTC-133 and K1 cell lines, and this may be useful for clinical treatment of some thyroid cancers. (authors)