OBJECTIVETo establish the patent ductus arteriosus model in preterm rats using the improved natural development method.

METHODSIn the light of the flaws of the natural development method in establishing the patent ductus arteriosus model, the experimental technology was modified to avoid the influence of fixation, dehydration, and section method on blood vessel diameter. Cesarean section was performed for a Wistar rat pregnant for 19 days, and 8 neonatal rats were obtained. After they were sacrificed by dislocation, they were embedded as a whole to avoid dehydration, and the microsection and horizontal section were made. After hematoxylin and eosin staining, a microscope was used to measure the inner diameters of the ductus arteriosus, the main pulmonary artery, and the descending aorta.

RESULTSAfter the cesarean section for the rat pregnant for 19 days, patent ductus arteriosus occurred in all the 8 neonatal rats. The measurements of the inner diameters of blood vessels were as follows: the long diameter and short diameter of the descending aorta were 354±106 and 182±140 μm, respectively; the short diameter of the ductus arteriosus was 155±122 μm, and its area was 36,847±42,582 μm(2); the long axis and short axis of the main pulmonary artery were 589±150 and 174±170 μm, respectively.

CONCLUSIONSThe improved natural development method can help to successfully establish the patent ductus arteriosus model in preterm rats.