BACKGROUND:Pulmonary hypertension stil lacks effective treatment measures. The effects of alprostadil in the treatment of pulmonary hypertension remain controversial. OBJECTIVE:To observe the effect of alprostadil in the treatment of pulmonary hypertension induced by chronic hypoxia. METHODS:24 experimental rats were randomly and evenly divided into control group, model group, and treatment group. The rats of model and treatment groups were fed in the hypoxic box to establish the animal model of pulmonary hypertension, and the rats of control group were fed in the normal air. After pulmonary hypertension induction, rats from the treatment group were intraperitonealy administered alprostadil injection (5 μg/kg per day) for 4 consecutive weeks. RESULTS AND CONCLUSION:Compared with the model group, the mean pulmonary artery pressure, right ventricular systolic pressure, pulmonary vascular thickness, size of blood vessels and alveolar wal thickness of rats in the treatment group were obviously decreased. The results suggest that alprostadil can decrease pulmonary artery pressure and prevent lung injury.

Methods: (i) Animal experiments. This study conducted experiments using specific pathogen-free (SPF) grade male C57BL/6J wild-type (WT) mice and APP/PS1 double transgenic mice. The animals were divided into three groups: WT group (WT mice, n = 5, receiving distilled water daily), APP/PS1 group (APP/PS1 double transgenic mice, n = 5, receiving distilled water daily), and BSTSD group [APP/PS1 double transgenic mice, n = 5, treated with BSTSD suspension at a dosage of 27 g/(kg·d) for 90 d]. Cognitive function was assessed using the Morris water maze (MWM). Post-experiment, hippocampal tissues were collected for analysis of pyramidal cell and synaptic morphology through hematoxylin-eosin (HE) staining and transmission electron microscopy (TEM). (ii) Cell experiments. The HT-22 cells were divided into control group (untreated), Aβ25-35 group (treated with 20 μmol/L Aβ25-35 for 24 h), icariin group (pre-treated with 20 μmol/L icariin for 60 min, followed by 20 μmol/L Aβ25-35 for an additional 24 h), and icariin + LY294002 group [treated with 20 μmol/L icariin and 20 μmol/L LY294002 (an inhibitor of the phosphoinostitide 3-kinases (PI3K) signaling pathway) for 60 min, then exposed to 20 μmol/L Aβ25-35 for 24 h], and cell viability was measured. Western blot was used to detect the expression levels of synapse-associated proteins [synaptophysin (SYP) and postsynaptic density-95 (PSD-95)] and PI3K signaling pathway associated proteins [phosphorylated (p)-PI3K/PI3K, p-protein kinase B (Akt)/Akt, and p-mechanistic target of rapamycin (mTOR)/mTOR]. Results: (i) Animal experiments. Compared with APP/PS1 group, BSTSD group showed that escape latency was significantly shortened (P < 0.01) and the frequency of crossing the original platform was significantly increased (P < 0.01). Morphological observation showed that pyramidal cells in the hippocampal CA1 region were arranged more regularly, nuclear staining was uniform, and vacuole-like changes were reduced after BSTSD treatment. TEM showed that the length of synaptic active zone in BSTSD treatment group was increased compared with APP/PS1 group (P < 0.01), and the width of synaptic gap was decreased (P < 0.01). (ii) Cell experiments. Icariin had no obvious toxicity to HT-22 cells when the concentration was not more than 20 μmol/L (P > 0.05), and alleviated the cell viability decline induced by Aβ25-35 (P < 0.01). Western blot results showed that compared with Aβ25-35 group, the ratios of p-PI3K/PI3K, p-Akt/Akt and p-mTOR/mTOR in icariin group were significantly increased (P < 0.01), while the protein expression levels of SYP and PSD-95 were increased (P < 0.01). These effects were blocked by LY294002 (P < 0.01). Conclusion BSTSD and icariin enhance cognitive function and synaptic integrity in AD models and provide potential therapeutic strategies through activation of the PI3K/Akt/mTOR pathway.