Neuronal injury and tumor necrosis factor-alpha immunoreactivity in the rat hippocampus in the early period of asphyxia-induced cardiac arrest under normothermia

Low survival rate occurs in patients who initially experience a spontaneous return of circulation after cardiac arrest（CA）. In this study, we induced asphyxial CA in adult male Sprague-Daley rats, maintained their body temperature at 37 ± 0.5°C, and then observed the survival rate during the post-resuscitation phase. We examined neuronal damage in the hippocampus using cresyl violet（CV） and Fluore-Jade B（F-J B） staining, and pro-inflammatory response using ionized calcium-binding adapter molecule 1（Iba-1）, glial fibrillary acidic protein（GFAP）, and tumor necrosis factor-alpha（TNF-α） immunohistochemistry in the hippocampus after asphyxial CA in rats under normothermia. Our results show that the survival rate decreased gradually post-CA（about 63% at 6 hours, 37% at 1 day, and 8% at 2 days post-CA）. Rats were sacrificed at these points in time post-CA, and no neuronal damage was found in the hippocampus until 1 day post-CA. However, some neurons in the stratum pyramidale of the CA region in the hippocampus were dead 2 days post-CA. Iba-1 immunoreactive microglia in the CA1 region did not change until 1 day postCA, and they were activated（enlarged cell bodies with short and thicken processes） in all layers 2 days postCA. Meanwhile, GFAP-immunoreactive astrocytes did not change significantly until 2 days post-CA. TNF-α immunoreactivity decreased significantly in neurons of the stratum pyramidale in the CA1 region 6 hours post-CA, decreased gradually until 1 day post-CA, and increased significantly again 2 days post-CA. These findings suggest that low survival rate of normothermic rats in the early period of asphyxia-induced CA is related to increased TNF-α immunoreactivity, but not to neuronal damage in the hippocampal CA1 region.

Effects of ethanol on insulin-like growth factor-Ⅰ system in primary cultured rat hepatocytes: Implications of JNK1/2 and alcoholdehydrogenase

AIM: To evaluate the effects of ethanol on the insulin- like growth factor-Ⅰ (IGF-Ⅰ) system involved in c-Jun N-terminal kinase (JNK1/2) and alcoholdehydrogenase (ADH) activity in primary cultured rat hepatocytes. METHODS: Hepatocytes isolated from male Sprague-Dawley rats were incubated with various concentrations of ethanol for different durations of time. The cells were pretreated with SP600125 (10 μmol/L) and 4-MP (200 μmol/L), and then treated with ethanol (200 mmol/L). We then measured IGF-Ⅰ secretion, IGF-Ⅰ mRNA expression, cell viability and JNK1/2 activity by radioimmunoassay, RT-PCR, MTT assay and Western blot, respectively (n = 6). RESULTS: Ethanol induced the activity of phospho (p)-JNK1/2, reaching a maximum at 60 min and then decreasing at 180 min. The effects of ethanol on the IGF-Ⅰ system were increased at 60 min (secretion: 7.11 ± 0.59 ng/mg protein vs 4.91 ± 0.51 ng/mg, mRNA expression: 150.2% ± 10.2% vs 101.5% ± 11.3%, P = 0.045) and then decreased at 180 min (secretion: 3.89 ± 0.25 ng/mg vs 5.4 ± 0.54 ng/mg protein; mRNA expression: 41.5% ± 10.4% vs 84.7% ± 12.1%, P = 0.04), however cell viability was decreased in a dose- and time-dependent manner. SP600125 blocked the ethanol-induced changes (at 60 min). Additionally, 4-methylpyrazole prevented the ethanol-induced decreases in the IGF-Ⅰ system, cell viability and p-JNK1/2 activity (at 180 min). CONCLUSION: This study suggests that ethanol- induced p-JNK1/2 activation is associated with the IGF-Ⅰ system and cell viability in hepatocytes. Furthermore, alcohol dehydrogenase is involved in the relationship between ethanol-induced inactivation of p-JNK1/2 and the changes of the IGF-Ⅰ system and cell viability.

Ethyl acetate fraction of cynanchum peniculatum and bee venom therapy in experimental canine stifle osteoarthritis

This study evaluated the therapeutic effects of the phytomedicine,ethyl acetate fraction of the Cynanchum peniculatum (EACP) and bee venom (BV) of the honey bee (Apis mellifera) for the treatment of experimental stifle osteoarthritis (OA) in 24 skeletally mature mixed small breed dogs (age 2 to 6 years,weight 2. 8 to 9 kg). One year after induction of OA,the animals were randomly allocated in 2 groups; the EACP-group received 10% solution of EACP 0. 5mL plus 0. 2 mL lidocaine; and the BV-group received 10% solution of BV 0. 5 mL plus 0. 2 mL lidocaine intraarticularly twice in a week in the OA-induced stifles for one month. The joint tissue specimens,synovial fluid (SF) and blood samples were collected prior to and 12 months after induction of OA,and one month posttreatment. TRAP levels in SF and serum were measured using a spectrophotometer,and TRAP-positive cells in joint tissues were identified by enzyme histochemistry. TIMP-2 in SF and serum was detected by ELISA. Histochemistry revealed an increased number of TRAP positive cells in tissues from OA-affected joints which was decreased after one month treatment with BV and EACP. After one-month administration of EACP and BV,the levels of TRAP in SF of the index stifles as well as that in the serum were significantly decreased (P<0. 05),whereas,the levels of TIMP-2 in SF of the index stifles as well as that in the serum were increased indicating the therapeutic effects of the EACP and BV on improvement of the conditions of OA.The intraarticular administration of EACP and BV were found effective for the treatment of OA in the dog.