Nicotine-evoked cytosolic Ca2+ increase and cell depolarization in capillary endothelial cells of the bovine adrenal medulla

Endothelial cells are directly involved in many functions of the cardiovascular system by regulating blood flow and blood pressure through Ca2+ dependent exocitosis of vasoactive compounds. Using the Ca2+ indicator Fluo-3 and the patch-clamp technique, we show that bovine adrenal medulla capillary endothelial cells (B AMCECs) respond to acetylcholine (ACh) with a cytosolic Ca2+ increase and depolarization of the membrane potential (20.3±0.9 mV; n=23). The increase in cytosolic Ca2+ induced by 10µM ACh was mimicked by the same concentration of nicotine but not by muscarine and was blocked by 100 µM of hexamethonium. On the other hand, the increase in cytosolic Ca2+ could be depressed by nifedipine (0.01 -100 µM) or withdrawal of extracellular Ca2+. Taken together, these results give evidence for functional nicotinic receptors (nAChRs) in capillary endothelial cells of the adrenal medulla. It suggests that nAChRs in B AMCECs may be involved in the regulation of the adrenal gland's microcirculation by depolarizing the membrane potential, leading to the opening of voltage-activated Ca2+ channels, influx of external Ca2+ and liberation of vasoactive compounds.

Polylactic acid nanoparticles targeted to brain microvascular endothelial cells / 华中科技大学学报（医学）（英德文版）

In this work, blank polylactic acid (PLA) nanoparticles with unstained surface were prepared by the nano-deposition method. On the basis of the preparation, the effect of surface modification on brain microvascular endothelial cells (BMECs) targeting was examined by in vivo experiments and fluorescence microscopy. The results showed that PLA nanoparticles are less toxic than PACA nanoparticles but their BMECs targeting is similar to PACA nanoparticles. The experiments suggest that drugs can be loaded onto the particles and become more stable through adsorption on the surface of PLA nanoparticles with high surface activity. The surface of PLA nanoparticles was obviously modified and the hydrophilicity was increased as well in the presence of non-ionic surfactants on PLA nanoparticles. As a targeting moiety, polysobate 80 (T-80) can facilitate BMECs targeting of PLA nanoparticles.

Fixation Methods for Implantable Port Chamber: Comparative Study Using Glue, Self-stabilizing Leg and Suture Fixations in Rabbits

OBJECTIVE: To evaluate the fixation strength and tissue reaction of the glue fixation and self-stabilizing leg fixation methods and to compare the results with those of the conventional tagging suture fixation method. MATER AND METHODS: Twelve healthy rabbits were selected and three different methods of implanting the port chamber were employed on the back of each rabbit. A total of thirty six port chambers were implanted with these three different methods, viz. the glue fixation method using tissue adhesive, the self-stabilizing leg method using a self-expandable stabilizing leg, and the suture fixation method. The fixation strength and the gross and histopathologic changes of each fixation method were evaluated at three days, one week, two weeks and four weeks after port implantation. RESULTS: The glue fixation method showed a good fixation strength, which was similar to that of the tagging suture method (p=0.3486). Five of the six ports (83%) implanted with the glue fixation method which were examined after two weeks showed cracks on the external surface, but this had no adverse effects on their function. A large amount of granulation tissue reaction was found at the bottom of the chamber (p=0.0025). The fixation with the self-stabilizing leg showed relatively lower fixation strength (p=0.0043), but no turning-over of the chamber occurred. The fixation strength improved with time after the first week, and minimal granulation tissue reaction was observed with this method. CONCLUSION: The glue fixation method exhibited equal fixation strength compared to the suture fixation, but showed cracking and a large amount of granulation tissue, whereas the fixation with a self-stabilizing leg showed weaker fixation strength.

Angiogenesis: characterization of a cellular model

Endothelial cell proliferation and differentiation into blood capillaries (i.e., angiogenesis) are essential for growth and development, wound healing, osetogenesis, etc. But abnormal angiogenesis during tumor progression could lead to serious consequences. Angiogenesis is a complex biochemical process, and is often difficult to study the molecular mechanism in vivo due to interference by multitude of factors. Here, I present a non-transformed capillary endothelial cell line as a model which has been extensively characterized morphologically and biochemically to study the fundamentals of the angiogenic process. Studies completed in our laboratory also evidenced that expression of Glc3Man9GlcNAc2-PP-Dol is intricately connected with the balance between the cellular proliferation and apoptosis during angiogenesis.