| Objective:It aims at establishing experimental device for matching the nicotine concentration of cigarette smoke and investigating the effects of inhalation of nicotine on the cardiovascular function,oxidative stress and inflammation in rats and its mechanism.Methods:Study on the experimental device for matching the nicotine concentration of electronic cigarettes vapor by gas purge.The nicotine concentration and peak area linear equation were established by GC-MS.It was used to be determination of different flow rates of air for the carrier gas purge of liquid nicotine formation of aerosol nicotine concentration.Sixteen male clean animal SD rats were randomly divided into two groups:the control group and the nicotine group.The nicotine group inhaled 1 h/d for 12 consecutive days.Anesthesia was given intraperitoneally with 3%pentobarbital sodium(0.1 ml/100 g).The right common jugular vein was cannulated for blood collection and centrifuged to prepare serum.Serum cotinine concentration in rats was determined by ELISA.Effects of long-time inhalation of nicotine by gas-purge on cardiovascular function,oxidative stress and inflammation in rats.Forty clean male SD rats were randomly divided into four groups.The experimental group was inhaled by inhalation of nicotine by air-purging.The rats were exposed for 4h,2h and 1h per day,respectively,and were determined as high,medium and low dose groups.The control group was housed under standard conditions.Systolic blood pressure(SBP)was measured at the end of each month for 3 consecutive months.Three months later,the right carotid artery was cannulated to measure the right carotid systolic pressure and other hemodynamic parameters.Blood samples were collected,centrifuged at low temperature.Serum was obtained and stored at-80 ? inrefrigerator.Full exposure of the chest and abdominal cavity,take the heart,thoracic aorta,lung,liver and kidney accurate weight determination.Myocardium and thoracic aorta specimens were subjected to hematoxylin and eosin(HE)to observe the pathological changes.Each experimental group took the same part of the thoracic aorta(4-5)mm length in vitro endothelium-dependent vasodilation function experiments.Thiobarbituric acid(TBA),nitrate reductase,xanthine oxidase and colorimetric method were used to detect the content of malondialdehyde(MDA),nitric oxide(NO),superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px).MDA,T-SOD and GSH-Px of herat,pulmonary and thoracic aorta were detected by enzyme-linked immunosorbent assay(ELISA).The levels of endothelial nitric oxide synthase eNOS,IL-1?,TNF-? in heart,lung and serum were detected.Results:It is concluded from studying on the experimental device for matching the nicotine concentration of electronic cigarettes vapor by gas purge.The nicotine peak area was linearly correlated with nicotine concentration by GC-MS(r2 = 0.9937).Electronic cigarette smoke nicotine concentration is 0.584?g/ml.Conditions:25 ?,nicotine liquid height of 20CM,air flow 1.1L/min,the experimental device aerosol nicotine concentration matched electronic cigarette smoke.Compared with the control group(2.05 ± 0.83)ng/ml,the serum cotinine concentration in the nicotine group was significantly higher than that in the control group(5.31 ± 0.62)ng/ml(P<0.01).Effects of long-time inhalation of nicotine by gas-purge on cardiovascular function,oxidative stress and inflammation in rats.Long-term inhalation of low,middle and high nicotine groups,compared with the control group,each exposure to nicotine group tail artery systolic blood pressure and carotid systolic blood pressure was significantly increased after 3 months(P<0.01).Pathological results showed that some myocardial fibers in medium and high dose nicotine group were unclear in structure and sarcoplasmic collapse occurred after inhaled 3-month long-term nicotine,.Compared with the control group,the medial thickness(MT)and total aorta area(TAA)was significantly increased in low,medium and high dose nicotine groups(P<0.05,P<0.01).Compared with the control group,the activity of SOD in serum of all the exposed nicotine groups was significantly lower(P<0.01),MDA content was significantly higher(P<0.05,P<0.01),GSH-Px activity was lower in low and medium nicotine groups,high-dose nicotine group GSH-Px activity was significantly reduced.Compared with the control group,serum nitric oxide(NO)levels in each nicotine group decreased significantly(P<0.05,P<0.01).Serum,heart,lung eNOS levels were significantly lower(P<0.01).Compared with the control group,the serum IL-1(3 in each exposed nicotine group were not significantly increased,and the serum TNF-a increased to some extent(P<0.01).IL-1? and TNF-? of heart and lung were increased to varying degrees(P<0.01).Conclusion:An experimental setup was established to match the nicotine concentration of the cigarette smoke.Experimental device gas can make rats infected with nicotine.Chonic inhaled nicotine by air-purged impaired cardiac function and cause high blood pressure.Oxidative stress and cardiopulmonary inflammatory reaction occured.The mechanism may be related to endothelial disfunction and disorder of sympathetic activation of parasympathetic system. |
PDF Full Text Request