Background: Nicotine can affect the development of Atherosclerosis (AS). Monocytes/macrophages are the important cells hi the AS lesions.
Objective: We studied the mechanisms of smoking on AS. The effects of nicotine on macrophage were investigated hi this study.
Methods: Different concentration of nicotine (6 × 10-9~-5 mol/L), different incubation time (3, 6, 9, 12, 18, and 24 horn s) and 7 β-hydroxycholesterol (50 μg ml) were schemed in this study. After exposure of macrophage to those different conditions, lactate dehydrogenase (LDH) activity and tumor necrosis factor-⃞ (TNF-α) content in the supernatant were assayed.
Results: Nicotine (6 × 10-9mol/L~-6×10-5mol/L) treatment resulted in a marked reduction of LDH in the supernatant (131,0±9.6 U/L. 129.7±6.2 U/L, 129.4±5.3 U/L, 134.2±8.4 U/L, and 138.3+9.7 U/L vs. 151.3+8.1 U/L, p <0.05 respectively, q-test). The same change trend was seen when co-treated with 7β-hydroxycholestrol and nicotine (135.7±7.6U/L, 135.6±6.6U/L, 136.1±6.7 U/L, 142.9±4.5 U/L, and 146.4±4.4 U/L vs. 152.4⃞6.2U/L, P<0.05 respectively, q-test). The peak effects occurred at the nicotine concentration of 6 × 10-7mol/L and the first 18-hours incubation. Nicotine (6 ×10-9mol/L~6 × 10-6mol L) treatment result in the increase of TNF-α in the supernatant (0.28±0.06 ng/mL, 0.32±0.05 ng/mL, 0.40±0.07 ng/mL. and 0.30±0.08 ng/mL vs. 0.17±0.05 ng/mL, p <0.05 respectively, q-test). Nicotine (6 × 10-5mol/L) treatment have no significant hicrease compared to the control group (0.21±0.08 ng/mL vs. 0.17+0.05 ng/mL, p >0.05, q-test). The peak effects occurred at the nicothie concentration of 6 × 10-7mol/L.
Conclusions: Nicotine can produce the beneficial effect on macrophage. Nicotine treatment can activate macrophage to produce TNF-α. Thus, nicotine can be a mechanism on the development of atherosclerosis.
The rapid global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the coronavirus disease 2019 (COVID-19) pandemic. Although COVID-19 is a class B infectious disease, the prevention and control measures used for it in China are commonly used for class A infectious diseases. In the process of the spread of the disease, hospitals will be a key point to influence this pandemic. To prevent and control nosocomial infection of SARS-CoV-2, methods and measures were formulated from the relevant laws and regulations of the National Health Commission of the People's Republic of China, practical experience of the pandemic, and evidence-based medicine in the hospitals fighting this disease. Thus, this report may provide useful recommendations for the prevention and control of COVID-19 in hospitals and clinics.