| Co-Investigator(Kenkyū-buntansha) |
UEDA Keiko HOKKAIDO UNIVERSITY HOSPITAL, fellow, 医学部・歯学部附属病院, 医員
UCHIDA Masaya HOKKAIDO UNIVERSITY HOSPITAL, fellow, 医学部・歯学部附属病院, 医員
OKAJIMA Satoru HOKKAIDO UNIVERSITY HOSPITAL, fellow, 医学部・歯学部附属病院, 医員
松田 直 北海道大学, 医学部・歯学部附属病院, 医員
|
|---|
| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2003: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2002: ¥1,600,000 (Direct Cost: ¥1,600,000)
|
|---|
| Research Abstract |
BPD is still a major problem for extremely premature infants. BPD is characterized as having a small number of alveoli with relatively large radius, and is considered as a consequence of intrauterine infection/inflammation. Our aim is to establish an animal model for BPD in rat. Pregnant rats (term 22.5day) were divided into four groups based on their treatment. Following treatments were given on the 21st gestational day. Group 1 was given an intra-amniotic injection of 1μg LPS together with an intra-peritoneal injection to fetus of 0.25μg hrG-CSF. Every pup was obtained by Cesarean section on the 22nd pregnant day. Neither mechanical ventilation nor supplemental oxygen was applied to the newborn pups. Lung specimens were obtained on the 1st,3 id,7th,14th,21st,45th, and 60th postnatal day, and were analyzed by photomicroscopy and by morphometry (Morphometrix, Davis CA, U.S.A.). Morphometrical parameters of Sv, (surface density), r (radius of alveoli), nv (number of alveoli) of group 1 and 2 were essentially the same but were evidently different from those of group 3 and 4 (group 3 and 4 exhibited no significant difference), indicating that LPS but not hrG-CSF affects the alveolar development. Alveoli in groups 1 and 2 pups showed smaller Sv, and larger r than those in groups 3 and 4 throughout the experimental course (60th days). The nv remained quite low in groups 1 and 2, while that of group 3 and 4 increased along their development. Photomicroscopically no sign of alveolar destruction was noted in lungs from every group, indicating that the lung structural changes seen in the group 1 and 2 pups are consistent with BPD. A single intra-amniotic injection of LPS to pregnant rats on the 21st gestational day induced lung structural changes consistent with BPD in pups. This would be the first rat model for BPD occurring independent of mechanical ventilation and oxygen supplement.
|
