The Changes Of Pulmonary Artery Pressure And Right Ventricle Hypertrophy Index Of The Rats With High Altitude Pulmonary Hypertension After Returning To The Plain And The Intervention Of Fluoxetine

Objective Observe the changes of pulmonary artery pressure and right ventricle hypertrophy index of the rats with high altitude pulmonary hypertension after returning to the plain and the intervention of fluoxetine on the rats.Methods 286 male Wistar rats were randomly divided into normal groups (N, n=13), nonintervention groups (W1-W7, n=13),fluoxetine treated groups(F1-7,n=13), distilled water treated groups(C1-7, n=13). The N groups were fed in the normal conditions , While the remaining groups were placed in a hypobaria and hypoxia chamber simulated to an altitude of 5000 meters. The F groups were gavaged with fluoxetine (3㎎·kg^-1.)for 30 days.The C group rats were gavaged with distilled water by weight for 30 days. TheW,C and F groups were placed in hypobaric hypoxia chamber for 30 days, and then placed in the plain.10 rats in each group were dected in 10,20,30days and 10,20,30,90days after returning to the plain. Mean pulmonary artery pressure (MPAP) and right ventricle /left ventricle + ventricular septum of the rats were examined by the Siemens-6002 blood pressure monitor system.Results①High altitude 3 periods: Along with the time extension in the hypobaria and hypoxia chamber ,MPAP and RV/LV+S gradually increased. MPAP: W2[(25.80±5.14)mmHg] and W3 [(28.45±3.0)mmHg] were higher than W1 [(19.06±0.68)mmHg] and W0 group[(18.60±2.80)mmHg, all P<0.01]; W3 group are higher than W2 group, but there wre no significantly difference ; High altitude 30d F group rat MPAP were lower than C group[(22.72±5.42/28.10±4.47) mmHg,P<0.05];Compared with F0[(18.60±2.80) mmHg],F1 group [(18.82±6.12) mmHg] and F3 group MPAP increased obviously ,all P<0.05。RV/LV+S: W2(0.52±0.07)and W3(0.52±0.11) RV/LV+S were obviously higher than W1(0.39±0.04)and W0 group(0.34±0.04),all P<0.05; Compared with W3 group , W2 group was higher,but there was no statistical significance ; High altitude 30d F group was lower than C group(0.45±0.04/0.52±0.06,P<0.05);Compared with F0(0.34±0.04)and F1 group (0.37±0.02),F3(0.43±0.05)and F4 group(0.45±0.04)RV/LV+S increased obviously ,P<0.01.②Returning to the plain 4 periods: Along with the extension in the plain ,MPAP and RV/LV+S gradually decreased . MPAP: W5[(23.36±2.16)mmHg],W6[(22.85±2.23) mmHg] and W7 [(20.53±3.61) mmHg] were lower than W3 and W4 [(27.83±2.74)mmHg)] , P<0.01;Returning to the plain 10d [(22.79±3.35/26.67±2.86)mmHg],20d [(19.37±2.93/23.55±2.68)mmHg] and 30d [(18.21±1.54/21.00±2.28) mmHg] F group rats MPAP were lower than same time C group,P<0.01;Compared with F3 and F4 group,MPAP,F6 and F7 group [(17.42±1.70)mmHg)] decreased obviously,P<0.05 . RV/LV+S:W5(0.36±0.05),W6 (0.35±0.03) and W7 (0.34±0.04) RV/LV+S were lower than W3 and W4 group (0.40±0.09),P<0.01;Return to plain 10d(0.38±0.06/0.44±0.09),20d(0.36±0.03/ 0.39±0.03)and 30d(0.35±0.01/0.38±0.03) F group RV/LV+S were lower than the same time C group ,P <0.05;Compared with the F3 group, F4,5,6 and F7 groups were lower, P<0.05.③Every group rats MPAP and RV/LV+S were nearly to normal control group level after returning to the plain 90 days.Conclusion MPAP and RV/LV+S ratio of the rats with high altitude pulmonary hypertension are reversibility after returning to the plain ; In the forming process of pulmonary hypertension, fluoxetine can reduce the pressure and right ventricular hypertrophy index of the rats with high altitude pulmonary hypertension; There is inversely proportional between level of pulmonary hypertension and right ventricular hypertrophy of the rats with HAPH and time returning to the plain.