Study on the relation between expression of angiotensin II receptor and apoptosis in myocardium in rats of endotoxemia / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To analyze the expression of angiotensin II (ANG II) receptor and apoptosis in myocardium in rats of endotoxemia.</p><p><b>METHODS</b>Model of endotoxemia was induced by intraperitoneal injection with lipopolysaccharide (LPS) 10 mg/kg in male Wistar rats and saline was injected into control group. The rats were killed at 2 h or 6 h after saline (control) or LPS . Expression of the correlation factors related to apoptosis of Bcl-2, Bax, AT1 and AT2 receptor in myocardial tissue were detected with immunohistochemistry (IHC), and changes of myocardial cells apoptosis was detected by the method of TUNEL. The gene expression of AT1 and AT2 receptor was examined by RT-PCR. The pathological changes of myocardial tissue were observed by electron microscope.</p><p><b>RESULTS</b>Compared with control group , the expression of AT1 and AT2 receptor were significantly decreased, especially in 6 h group; and the expression of Bcl-2 and Bax were decreased, the ratio of Bcl-2/Bax had the downtrend as well as the apoptosis of myocardial cells.</p><p><b>CONCLUSION</b>Interfered by LPS, the down regulation of AT1 and AT2 receptor expression has the negative relation with apoptosis of myocardial cells, this result indicated that down regulation of AT1 and AT2 receptor expression maybe related to cardiac functional impairment, which maybe help us to find a new protective path to prevent myocardial damage induced by systemic inflammatory.</p>

Mesenchymal stem cells exist in the compact bones from four species of mammals / 中国实验血液学杂志

The biological properties of cultured mesenchymal stem cells (MSC) have been intensively investigated, while there is still a paucity of information about the definite in vivo sites that harbor these stem cells due to the lack of specific surface markers. Previous data have demonstrated that human and murine MSC can be isolated from the compact bones. To investigate if it is the case for other species, the femurs from Wistar rats, Beagles, C57 mice and New Zealand rabbits were collected, minced and digested with collagenase type I. The digested bone fragments were seeded into the medium for human bone marrow culture after removal of the suspended cells in the digestion. The results showed that the fibroblast-like cells were observed to migrate from the bone fragments after several days of culture, and they gradually formed an adherent confluent layer. The adherent cells could be passaged and expressed homogenously the mesenchymal cell marker vimentin. Differentiation assays showed that these cells had the capacity to differentiate into osteoblasts and adipocytes. In conclusion, the results here provide new information for the further investigations on the in vivo biological features of MSC in the context of the simplicity of the compact bone structure.