Cellular energy status of the gastric mucosa and gastric mucosal prevention by vitamin A in indomethacin-treated rats

To evaluate the cellular energy status of gastric mucosa during the development of gastric mucosal damage and its prevention by application of a cytoprotective scavenger (vitamin A) in rats treated with indomethacin, the tissue levels of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP) and lactate were measured enzymatically, while the concentration of cyclic adenosine monophosphate (cAMP) was measured by radioimmunoassay, 4 h after the treatment with indomethacin and vitamin A simultaneously. It was found that a) the tissue levels of ATP, cAMP, AMP and the ratio of ATP/ADP were increased dose-dependently in the gastric mucosa in connection with the development of gastric mucosal prevention produced by vitamin A, b) the tissue level of ADP was decreased dose-dependently by vitamin A in indomethacin-treated rats, and c) the value of "energy charge" and the ratio of the ATP-ADP was unchanged during the vitamin A treatment in indomethacin-treated rats. The presence of tissue hypoxia could not be proved either in the development of indomethacin-induced gastric mucosal damage nor in the prevention of gastric mucosal damage by vitamin A.     

Involvement of apoptosis in neurological injury after hypothermic circulatory arrest: a new target for therapeutic intervention?

BACKGROUND: This study was undertaken to evaluate the role of apoptosis in neurological injury after hypothermic circulatory arrest (HCA). METHODS: Twenty-one pigs (27 to 31 kg) underwent 90 minutes of HCA at 20 degrees C and were electively sacrificed at 6, 24, 48, and 72 hours, and at 7, 10, and 12 days after HCA, and compared with unoperated controls. In addition, 3 animals that had HCA at 10 degrees C, and 3 treated with cyclosporine A (CsA) in conjunction with HCA at 20 degrees C, were examined 72 hours after HCA. After selective perfusion and cryopreservation, all brains were examined to visualize apoptotic DNA fragmentation and chromatin condensation on the same cryosection of the hippocampus: fluorescent in situ end labeling (ISEL) was combined with staining with a nucleic acid-binding cyanine dye (YOYO). RESULTS: In addition to apoptosis, which was seen at a significantly higher level (p = 0.05) after HCA than in controls, two other characteristic degenerative morphological cell types (not seen in controls) were characterized after HCA. Cell death began 6 hours after HCA and reached its peak at 72 hours, but continued for at least 7 days. Compared with the standard protocol at 20 degrees C, HCA at 10 degrees C and CsA treatment both significantly reduced overall cell death after HCA, but not apoptosis. CONCLUSIONS: The data establish that significant neuronal apoptosis occurs as a consequence of HCA, but at 20 degrees C, other pathways of cell death, probably including necrosis, predominate. Although preliminary results suggest that the neuroprotective effects of lower temperature and of CsA are not a consequence of blockade of apoptotic pathways, inhibition of apoptosis nevertheless seems promising as a strategy to protect the brain from the subtle neurological injury that is associated with prolonged HCA at clinically relevant temperatures.     

Changes of placental syndecan-1 expression in preeclampsia and HELLP syndrome

Preeclampsia is characterized by maternal systemic anti-angiogenic and pro-inflammatory states. Syndecan-1 is a cell surface proteoglycan expressed by the syncytiotrophoblast, which plays an important role in angiogenesis and resolution of inflammation. Our aim was to examine placental syndecan-1 expression in preeclampsia with or without hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. Placentas were obtained from women in the following groups: (1) late-onset preeclampsia (n?=?8); (2) early-onset preeclampsia without (n?=?7) and (3) with HELLP syndrome (n?=?8); (4) preterm controls (n?=?5); and (5) term controls (n?=?9). Tissue microarrays (TMAs) were constructed from paraffin-embedded placentas. TMA slides were immunostained for syndecan-1 and evaluated using microscopy, virtual microscopy, and semi-automated image analysis. Maternal sera from patients with preeclampsia (n?=?49) and controls (n?=?32) were immunoassayed for syndecan-1. BeWo cells were treated with Forskolin or Latrunculin B or kept in ischemic conditions. SDC1 expression and syndecan-1 production were investigated with qRT-PCR, confocal microscopy, and immunoassays. Syndecan-1 was localized to the syncytiotrophoblast apical membrane in normal placentas. Syndecan-1 immunoscores were higher in late-onset preeclampsia (p?=?0.0001) and early-onset preeclampsia with or without HELLP syndrome (p?=?0.02 for both) than in controls. Maternal serum syndecan-1 concentration was lower in preeclampsia (median, 673 ng/ml; interquartile range, 459–1,161 ng/ml) than in controls (1,158 ng/ml; 622–1,480 ng/ml). SDC1 expression and syndecan-1 immunostainings in BeWo cells and syndecan-1 concentrations in supernatants increased during cell differentiation. Disruption of the actin cytoskeleton with Latrunculin B decreased syndecan-1 release, while ischemic conditions increased it. Syncytiotrophoblastic syndecan-1 expression depends on the differentiation of villous trophoblasts, and trophoblastic syndecan-1 release is decreased in preeclampsia and HELLP syndrome. This phenomenon may be related to the disturbed syncytiotrophoblastic cortical actin cytoskeleton and associated with maternal anti-angiogenic and pro-inflammatory states in these syndromes.