Propofol is known to cause vasorelaxation of several systemic vascular beds. However, its effect on the pulmonary vasculature remains controversial. In the present study, we investigated the effects of propofol on human pulmonary arteries obtained from patients who had undergone surgery. Arterial rings were mounted in a Multi-Myograph system for measurement of isometric forces. U46619 was used to induce sustained contraction of the intrapulmonary arteries, and propofol was then applied (in increments from 10–300 µM). Arteries denuded of endothelium, preincubated or not with indomethacin, were used to investigate the effects of propofol on isolated arteries. Propofol exhibited a bifunctional effect on isolated human pulmonary arteries contracted by U46619, evoking constriction at low concentrations (10–100 µM) followed by secondary relaxation (at 100–300 µM). The extent of constriction induced by propofol was higher in an endothelium-denuded group than in an endothelium-intact group. Preincubation with indomethacin abolished constriction and potentiated relaxation. The maximal relaxation was greater in the endothelium-intact than the endothelium-denuded group. Propofol also suppressed CaCl₂-induced constriction in the 60 mM K⁺-containing Ca²⁺-free solution in a dose-dependent manner. Fluorescent imaging of Ca²⁺ using fluo-4 showed that a 10 min incubation with propofol (10–300 µM) inhibited the Ca²⁺ influx into human pulmonary arterial smooth muscle cells induced by a 60 mM K⁺-containing Ca²⁺-free solution. In conclusion, propofol-induced arterial constriction appears to involve prostaglandin production by cyclooxygenase in pulmonary artery smooth muscle cells and the relaxation depends in part on endothelial function, principally on the inhibition of calcium influx through L-type voltage-operated calcium channels.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid ; Arteries ; Calcium ; Calcium Channels ; Constriction ; Endothelium ; Humans* ; Indomethacin ; Myocytes, Smooth Muscle ; Propofol* ; Prostaglandin-Endoperoxide Synthases ; Pulmonary Artery* ; Relaxation ; Vasoconstriction* ; Vasodilation

Objective: To perform lymphocyte micronucleus analysis on radiation workers with long-term exposure to low doses ionizing radiation, Evaluate the health condition of radiation workers, and provide the evidence for strengthening surveillance of radiation workers. Methods: From January 1, 2013 to December 21, 2016, a statistical analysis and evaluation was conducted of the peripheral lymphocytes micronucleus rate in 5 901 radiation workers who had undergone medical examinations of employees at Chinese Academy of Medical Sciences Institute of Radiation Medicine. Results: The micronucleus rates in radiation workers of the on-job group were higher than the pre-job group (P<0.01) . Significant difference was found among the different sex (t=5.97) , different types (χ²=378.69) , different levels of work units (χ²=115.48) . Significant difference was found among the micronucleus rates of 672 radiation workers of the on-job group from 2013 to 2016 (χ²=92.57, P<0.01) . Conclusion The peripheral lymphocytes micronucleus rate of radiation workers were significantly higher than non-contact workers. Significant increasing trend of micronucleus rates was noted among the radiation worker with increasing exposure time. The peripheral lymphocytes micronucleus rates of interventional therapy workers were highest. The peripheral lymphocytes micronucleus rates of Private hospitals workers were highest. This phenomenon deserves attention. Protection needs to be strengthened to ensure the health of radiation workers.