Changes of peptide growth factors on the development of lungs in rats / 中华围产医学杂志

ABSTRACT

Objective To investigate the role of insulin-like growth factor (IGF)-Ⅰ , ⅠⅠ , platelet-derived growth factors (PDGF)-AA,-BB and keratinocyte growth factor (KGF) in various stages of the pulmonary development in rats. Methods All lung tissues of fetal and neonatal rats were collected at the gestational age 18, 20, 21 d, and 1, 4, 7, 10 and 21 d after birth. The expression of IGF-Ⅰ , IGF- ⅠⅠ , PDGF-AA and PDGF-BB was detected by immunohistochemistry and Western blot, respectively. The levels of IGF- Ⅰ , IGF-ⅠⅠ , PDGF-A, PDGF-B and KGF mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Results The peak expression of IGF-Ⅰ was at 4, 7 and 10 d after birth. IGF-ⅠⅠ was detectable early in fetal lung development and decreased gradually until 21 d after birth. The changes of IGF- Ⅰ , ⅠⅠ mRNA were similar to IGF- Ⅰ , ⅠⅠ polypeptides. The PDGF-A,PDGF-B mRNA were abundant early in fetal lung development. The steady state of PDGF-A chain mRNA was significantly different only at 7 d (0. 97?0. 23,P0. 05). The PDGF-AA polypeptide was abundant early in fetal lung development, and the expression peak was found in 1, 4 and 7 d after birth. KGF mRNA was higher in the fetal samples than that of rats after birth, but no difference in postnatal rats at all time points. Conclusions Peptide growth factors may play a critical role in the development of lung in rats.