动物造模,药效评价,肺损伤 z-bio 2024-07-25 529

　　1. Modeling material animals: Adult Wistar rats, male, weighing 230-270g; Medications: pentobarbital, physiological saline, heparin, lactate Ringer's solution; Equipment: Syringes, surgical instruments, electric blankets, micro infusion pumps, multi-channel physiological recorders.

　　2. Method of modeling: Fasting for 12 hours before surgery, drinking water freely, and intraperitoneal injection of 1% pentobarbital (40mg/kg). After the animal is anesthetized, it is fixed in a supine position on the rat operating table and the rectal temperature is maintained at (36.0 ± 0.5) ℃ using an electric blanket. Expose the right internal carotid artery and use a 22G arterial puncture needle to continuously monitor mean arterial pressure (MAP) and heart rate (HR); Expose the right femoral artery and femoral vein and place tubes together for the extraction of blood and fluid infusion; Tail vein puncture catheterization. And connect a micro infusion pump for infusion of drugs or physiological saline. All surgeries are performed strictly under aseptic conditions, and after completion, they are stabilized for 30 minutes. Then, slowly extract 2.0ml/min (kg · min) of blood from the femoral artery, store it with heparin for reinfusion, and continue to extract or reinfuse blood to stabilize the MAP at around 5.32kPa for 60 minutes to create a hemorrhagic shock model. During resuscitation, all autologous blood will be returned and lactate Ringer's solution will be added to maintain a MAP of 10.64-13.33kPa. The control group animals only had their neck and thigh blood vessels exposed by incision.

　　3. The principle of modeling is that severe hemorrhagic shock can cause acute lung injury.

　　4. Compared with the control group, the changes after modeling showed that CD11b/CD18 expression on the surface of polymorphonuclear neutrophils (PMNs) at various time points (2, 4, 8, and 12 hours) after resuscitation in the modeling group [2h: (50 ± 6)%, 4h: (57 ± 9)%, 8h: (60 ± 10)%, 12h: (47 ± 8)%]; The control group showed an increase of (23 ± 4)% in MPO activity in lung tissue [modeling group 2h: (1.12 ± 0.08) U/g, 4h: (1.76 ± 0.11) U/g, 8h: (2.34 ± 0.13) U/g, 12h: (2.31 ± 0.12) U/g]; The control group showed an increase of (0.43 ± 0.04) U/g.

　　Under light microscopy, the control group had uniform size and morphology of alveoli, clear structure, and no bleeding or PMN infiltration in the alveolar cavity. The modeling showed severe damage to the alveolar wall, significant thickening of the vascular wall and alveolar septum, and worsening of lung injury with prolonged resuscitation time. Under electron microscopy, the ultrastructure of lung tissue in the control group was normal. Severe lung tissue damage was observed in the model, characterized by swelling and disappearance of septa in type I epithelial cells, decreased synthesis and secretion of surfactant in type II epithelial cells, degranulation of endoplasmic reticulum, and significant reduction in free ribosomes.