[Enhancement of NMDA receptor sensitivity by thrombin and its relationship with tissue transglutaminase].

OBJECTIVE: To explore the possible relationship between the thrombin induced potentiation of rat cerebellum granular cell N-methyl-D-aspartate (NMDA) receptor function and the change of intracellular tissue transglutaminase (tTG). METHODS: Primary cultured rat cerebellum granular cells were pretreated by using thrombin (0.01 U/ml) with or without co-pretreatment of 0.5 x 10(-4) mol/L MDC (monodansylcadaverine, a tTG inhibitor) 30 minutes. Induce cells mentioned above to undergo apoptosis with different concentration of NMDA (0.1 x 10(-4) mol/L, 0.25 x 10(-4) mol/L and 0.5 x 10(-4) mol/L). Flowcytometer was applied 3 hours later to detect the changed function of NMDA receptor by counting percentage of apoptotic cells. RT-PCR was used to compare the tTG mRNA level in the cerebellum granular cells treated with NMDA of same dosage with/without thrombin pretreatment. RESULTS: Thrombin pretreatment increased the percentage of apoptosis cells induced by NMDA [(8.3 +/- 0.5)% to (15.1 +/- 0.8)% at 0.1 x 10(-4) mol/L, (14.1 +/- 1.1)% to (23.8 +/- 0.7)% at 0.25 x 10(-4) mol/L, (26.8 +/- 1.9)% to (33.7 +/- 2.1)% at 0.5 x 10(-4) mol/L)]; and this effect was inhibited by co-pretreatment MDC with thrombin, cell apoptosis decreased to (5.8 +/- 1.2)%, (11.5 +/- 1.5)% and (19.0 +/- 1.7)%; Thrombin increased intracellular tTG mRNA levels comparing with those without thrombin pretreatment. CONCLUSION: Thrombin potentiates rat cerebellum granular cell NMDA receptor function by increasing intracellular tissue transglutaminase.

Effects of extracellular Ca(2+) influx and intracellular Ca(2+) release on ethanol-induced cytoplasmic Ca(2+) overload in cultured superior cervical ganglion neurons.

The present research was designed to investigate the interference of Ca(2+) homeostasis by ethanol on the primary cultured superior cervical ganglion (SCG) neurons. (1) Using the whole cell patch clamp recording, the amplitudes of voltage-dependent Ca(2+) channel (VDCC) currents could be reduced by ethanol in a concentration-dependent manner. Ethanol (100mM) inhibited about 25% of Ca(2+) channel current. However, the activation of Ca(2+) channel was not affected by ethanol at those concentrations. (2) The similar extent inhibitions of 100mM ethanol on the increments of intracellular Ca(2+) concentration ([Ca(2+)](i)) induced by 40 mM KCl and 1 microM A23187 were also observed in the fluo-3-AM loaded superior cervical ganglia (SCG) via detecting the change of [Ca(2+)](i) with a laser scanning confocal microscopy. In contrast, the basal [Ca(2+)](i) was significantly increased by ethanol alone in a concentration-dependent manner. These phenomena were also observed even under Ca(2+) free bath solution or the solution added 300 microM cadmium chloride conditions. Together with above results, our data suggest that ethanol increases basal [Ca(2+)](i), but it also inhibits the extracellular Ca(2+) influx through VDCC and ionophore channel. And the augment of basal [Ca(2+)](i) induced by ethanol might attribute to the Ca(2+) releasing from intracellular Ca(2+) pools.

[Content of nitric oxide in cerebrospinal fluid from patients with neurocysticercosis].

OBJECTIVE: To evaluate the relationship between the concentration of nitric oxide (NO) and cytological change in cerebrospinal fluid (CSF) and the onset of neurocysticercosis in patients. METHODS: NO Level in CSF was detected in 30 cases of neurocysticercosis, 20 cases of tuberculous meningitis (TBM) and 20 healthy people as control by using Griess method. The cytological components in CSF were also examined. RESULTS AND CONCLUSION: Griess method was proved to be a rapid and accurate technique for the detection of NO content in CSF. The NO concentration in cases of neurocysticercosis and TBM was significantly higher than that of control(P < 0.01). The neurocysticercosis cases showed the highest CST NO level which was considerably higher than that of TBM cases(P < 0.05). Among the cytological changes, the neurocysticercosis cases also showed a higher count of eosinophils than that of TBM cases and control (P < 0.01). The NO level and eosinophils count in CSF increased significantly in patients with neurocysticercosis.