The radioassay of glutamic decarboxylase (GAD) was modified by taking NaOH as trapped agent instead of phenylethylamine. The results showed that the coefficient of variation (CV) within same sample was 9.6 % and the radioactivity remains stable after 72 hours if use NaOH as trap agent. It is significantly stable than use phenylethylamine as trap agent, which the CV was 31.9 % and the radioactivity decreased 47% within the first hour and decreased to background after 6 hours. The reabsorption experiment shows over 80 % of 14CO2 can be reabsorption by NaOH within 6 hours. It is suggested that NaOH is a much better trap agent than phenylethylamine and the sensitivity can increase 1.66 folds. Using this method the GAD activity in 0.39～ 17.8 rng of brain tissue can be measured and it is success in determine the GAD activity both in rat brain tissue and cultured neurons.

Objective To study the effect of hypoxial endothelia cell conditional medium(HECCM)on the proliferation of pulmonary arterial muscle cell(PASMC).Methods MTT assay was used to test the proliferation,immuno-cytochemistry was used to identify the expression of ?-SM-actin.Results(1)HECCM could promote the proliferation of PASMC,down-regulate their expression of ?-SM-actin.(2)DDPH could up-regulate the expression of ?-SM-actin in PASMC which was time-dependant.Conclusions DDPH could reverse the phenotype transformation of PASMC exposed to HECCM,the action was time-dependant.After some time DDPH could reversly transform PASMC to the normal contractile phenotype.

Whether melatonin not only inhibits the growth of H22 hepatocarcinoma cells but also induces apoptosis in vitro was assessed. The anti-proliferative effects of melatonin on tumor cells was observed by MTT assay and tumor cells growth curve assay. And the apoptosis of the cells was studied by acridine orange fluorescence assay and flow cytometry. The cell cycle of the tumor cells was also observed by flow cytometry. It was found that melatonin could significantly inhibit the growth of H22 hepatocarcinoma cells. Incubated with melatonin, chromatin condensation of the tumor cells was observed by fluorescence microscopy. Compared with control, the percentage of apoptotic cells was increased, and the proportion of G0/S increased but that of G2/M decreased. It was suggested that melatonin could directly inhibit the growth of H22 hepatocarcinoma cells by inducing apoptosis and extending the length of cell cycle of the tumor cells.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Cycle ; drug effects ; Cell Division ; drug effects ; Flow Cytometry ; Humans ; Liver Neoplasms ; pathology ; Melatonin ; pharmacology ; Tumor Cells, Cultured

To investigate the role of mitochondria in neuronal apoptosis, ischemia-reperfusion mediated neuronal cell injury model was established by depriving of glucose, serum and oxygen in media. DNA fragmentation, cell viability, cytochrome C releasing, caspase3 activity and mitochondrial transmembrane potential were observed after N2a cells suffered the insults. The results showed that N2a cells in ischemic territory exhibited survival damage, classical cell apoptosis change, DNA ladder and activation of caspase3. Apoptosis-related alterations in mitochondrial functions, including release of cytochrome C and depression of mitochondrial transmembrane potential (deltapsim) were testified in N2a cells after mimic ischemia-reperfusion. Moreover, activation of caspase3 occurred following the release of cytochrome C. However, the inhibitor of caspase3, Ac-DEVD-CHO, couldn't completely rescue N2a cells from apoptosis. Administration of cyclosporine A, an inhibitor of mitochondria permeability transition pore only partly inhibited caspase3 activity and reduced DNA damage. Interestingly, treatment of Z-IETD-FMK, an inhibitor of caspase8 could completely reverse DNA fragmentation, but can't completely inhibit caspase3 activity. It was concluded that there were caspase3 dependent and independent cellular apoptosis pathways in N2a cells suffering ischemia-reperfusion insults. Mitochondria dysfunction may early trigger apoptosis and amplify apoptosis signal.
Animals ; Apoptosis ; physiology ; Caspase 3 ; Caspases ; biosynthesis ; Cytochromes c ; biosynthesis ; Mice ; Mitochondria ; physiology ; Neuroblastoma ; pathology ; Neurons ; pathology ; Reperfusion Injury ; metabolism ; pathology ; Tumor Cells, Cultured