[Effects of propofol on expression of hippocampal survivin and Caspase-3 in newborn rats].

OBJECTIVE: Intravenous anesthetics, such as propofol, are widely used in general anesthesia. Neurodegeneration and neurocognitive impairment after exposure to propofol in neonatal rats have raised concerns regarding the safety of pediatric anesthesia. We examined the effects of neonatal propofol exposure on brain cell viability, as well as expression of hippocampal survivin and Caspase-3 mRNA and protein. METHODS: One hundred male Sprague-Dawley rats aged 7 d that were weighed 10-15 g were randomly divided into 4 groups (n = 25 each group). Group A: the rats were injected with no drugs. Group B: the rats were intraperitoneally injected with 50 mg/kg propofol. Group C: the rats were first intraperitoneally injected with 50 mg/kg propofol and another 50 mg/kg propofol was used when the dynamic response of rats appeared again. Group D: the rats were first intraperitoneally injected with 50 mg/kg propofol and another 50 mg/kg propofol was used three times once the dynamic response of rats appeared. To study the effects of propofol exposure on respiratory and metabolic function, arterial blood was aspirated from the left ventricle of neonatal rats 2 h after discontinuation of propofol. pH, PaO(2), PaCO(2), HCO(3)(-), BE and SaO(2) were detected by blood gas analyzer. Moreover, to examine the effects of propofol exposure on short-term cellular viability, the ultrastructure of neurons was observed by transmission electron microscope and Fluoro-Jade B (FJB) staining was performed to examine neuronal degeneration in hippocampal CA1 region of neonatal rats. Survivin and Caspase-3 mRNA and protein expression in hippocampus were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting 2 h after discontinuation of propofol. RESULTS: The time of anesthesia maintaince in newborn rats was the longest in Group D and the time of anesthesia maintaince in Group C was longer than that in Group B. Two hours after discontinuation of propofol, pH, PaO(2), PaCO(2), HCO(3)(-), BE and SaO(2) of arterial blood in rats were not significantly different among groups A, B, C and D (P > 0.05). The structure of hippocampal neurons was normal in Group A and Group B while 100 mg/kg propofol resulted in nuclear blebbing and 200 mg/kg propofol led to nuclear fragmentation, chromatin condensation and apoptotic bodies. Cellular degeneration, as measured by Fluoro-Jade B staining, significantly increased in hippocampal CA1 region in the anesthesia groups compared with littermates in the no anesthesia group. FJB-positive stained degenerative neurons in groups B, C and D were (2.5 ± 1.3), (7.1 ± 2.3) and (9.4 ± 2.6), which were different from that in Group A (0.6 ± 0.3) (P < 0.05). Moreover, the number of FJB-positive neurons was the highest in Group D, that in Group C was more than that in Group B. At the same time point, apoptosis was measured by expression of Caspase-3 and Survivin mRNA and protein in hippocampus of rats. Caspase-3 mRNA in groups A, B and C was (0.78 ± 0.12), (0.84 ± 0.17) and (0.89 ± 0.19), while Caspase-3 protein in groups A, B and C was (0.22 ± 0.05), (0.26 ± 0.07) and (0.21 ± 0.06). Survivin mRNA in groups A, B and C was (0.56 ± 0.12), (0.58 ± 0.15) and (0.53 ± 0.16), while Survivin protein in these 3 groups was (0.24 ± 0.07), (0.21 ± 0.05) and (0.23 ± 0.06). Compared with that in Group A, Caspase-3 and Survivin mRNA and protein were not significantly different among Group B and Group C (P > 0.05). However, Caspase-3 mRNA and protein in Group D were (1.21 ± 0.14) and (0.42 ± 0.12), which were higher than that in the other 3 groups (P < 0.05). Survivin mRNA and protein in Group D were lower than that in the other 3 groups (P < 0.05). CONCLUSIONS: A high dose of propofol exposure may destroy the structure of neurons, induce neurodegeneration, increase Caspase-3 activity and inhibit survivin expression in hippocampus of newborn rats in vivo.

Exogenous morphine inhibits human gastric cancer MGC- 803 cell growth by cell cycle arrest and apoptosis induction.

Morphine is not only an analgesic treating pain for patients with cancer but also a potential anticancer drug inhibiting tumor growth and proliferation. To gain better insight into the involvement of morphine in the biological characteristics of gastric cancer, we investigated effects on progression of gastric carcinoma cells and the expression of some apoptosis-related genes including caspase-9, caspase-3, survivin and NF-κB using the MGC-803 human gastric cancer cell line. The viability of cells was assessed by MTT assay, proliferation by colony formation assay, cell cycle progression and apoptosis by flow cytometry and ultrastructural alteration by transmission electron microscopy. The influences of morphine on caspase-9, caspase-3, survivin and NF-κB were evaluated by semi-quantitative RT-PCR and Western blot. Our data showed that morphine could significantly inhibit cell growth and proliferation and cause cell cycle arrest in the G2/M phase. MGC-803 cells which were incubated with morphine also had a higher apoptotic rate than control cells. Morphine also led to morphological changes of gastric cancer cells. The mechanism of morphine inhibiting gastric cancer progression in vitro might be associated with activation of caspase-9 and caspase-3 and inhibition of survivin and NF-κB.