Changes In Lung Tissue Apoptosis Of Rats From High Altitude Pulmonary Hypertension After Returning To Plains And The Interference Effect Of 5-HT Inhibitors

Objective In this paper, intervention effect of fluoxetine drugs and the impact ofreturning to plains on lung tissue apoptosis of rats from high altitude pulmonaryhypertension are observed. This paper also explores the efficacy from the twoapproaches.Methods 220 male Wistar rats were randomly divided into 22 groups: the normalcontrol group (N,10 rats), non-intervention group(W1-7,10 rats), fluoxetine druggroup (F1-7 ,10 rats), distilled water group (C1-7,10 rats) and 7 phases: plateau 10days , plateau 20 days, plateau 30 days and returned to plain 10 days, plain 20 days,plain 30 days, plain 90 days. Rats in the normal control group were raised in anorthobaric environment. Rats in the blank control,experimental group andexperimental control groups were kept in a hypobaric chamber, which simulated theenvironment of the 5000m altitude . Apoptosis of lung tissue was detected by flowcytometry.Results 1. Compared with group N, with the prolonged high altitude hypoxia and low pressure, early apoptosis in lung tissue in group W was observed in a progressively increasing tendency while the proportion of living cells showing a progressively decreased tendency. In the plateau periods, comparison of all groups presented significant difference (P < 0.05). 2. When separated from low altitude hypoxia and low pressure, early apoptosis in lung tissue in group W gradually transferred to late apoptosis and apoptosis. The proportion of living cells showed progressive recovery. Early apoptosis, late apoptosis and apoptosis have been significantly reduced in group W6, presenting significant difference from W3, 4, 5 (P <0.05), and insignificant difference from between W7. 3. Indexes in W7 showed no statistical difference from group N. 4. Comparison between group F and C at every period showed no significant difference.Conclusion 1. Low pressure and hypoxia will induce the increased early apoptosis of lung tissue and the proportion of apoptosis was positively correlated with hypoxia time. 2. When returning to plains, as the time away from hypoxia and low pressure conditions, the apoptosis of lung tissues was weakened, and eventually recovered. 3. Fuoxetine presented no intervention effect or long‐term effect on lung tissue apoptosis from high altitude pulmonary hypertension.