Department of Pediatrics, Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong 515041, China.
Chin Med J (Engl). 2009 Sep 5;122(17):2013-6.
Epidermal growth factor (EGF), a mitogenic polypeptide that binds to cell surface receptors, is an important regulator of cell differentiation and fetal lung surfactant synthesis. We investigated the preventive and therapeutic effects of EGF in respiratory distress syndrome, by administering EGF and dexamethasone (Dex) to mother rat before delivery.
Six female Sprague-Dawley (SD) rats were assigned to three groups (2 rats each); EGF or Dex was given to pregnant rats (EGF group and Dex group, respectively) from gestational day 16 to day 18 by intraperitoneal injection, while the group with normal saline injection was used as negative controls. Fetal rats were taken out of womb by hysterotomy on day 19 of pregnancy, then 24 fetal rats were randomly chosen from each group. Their body weights were measured, and pulmonary surfactant protein-A and -B (SP-A and SP-B) antigens were determined by immunohistochemical staining in each group. The histologic structure was examined under a light microscope, a light microscopic image system or an electron microscope.
The expressions of SP-A and SP-B could be detected in each group. A significant difference was observed for SP-A and SP-B in the EGF and Dex groups compared with the control group (P < 0.01). Image analysis showed that the relative values of air space area and interalveolar septa area in the EGF and Dex groups were significantly greater than those in the control group (P < 0.01), while no significant difference was found between the two groups (P > 0.05). The ultrastructural features of fetal lungs showed that the number of alveolar type II cells containing lamellar bodies in the EGF and Dex groups was apparently increased compared with that in the control group. The mean body weight of fetus from the Dex group was smaller than that from the control group ((1.3192 +/- 0.0533) g, (1.3863 +/- 0.0373) g), but there was no significant difference between the EGF group and the control group ((1.3986 +/- 0.0730) g, (1.3863 +/- 0.0373) g).
Maternal treatment with EGF and Dex on days 16 - 18 of gestation could promote morphogenesis and increase the surfactant levels in premature fetal lung. However, maternal treatment with Dex, not EGF, decreased the body weight.
表皮生长因子（EGF）是一种有丝分裂多肽，能与细胞表面受体结合，是细胞分化和胎儿肺表面活性剂合成的重要调节剂。我们通过在分娩前给母鼠注射 EGF 和地塞米松（Dex）来研究 EGF 在呼吸窘迫综合征中的预防和治疗作用。
将 6 只雌性 Sprague-Dawley（SD）大鼠分为三组（每组 2 只）；EGF 或 Dex 分别从妊娠第 16 天到第 18 天通过腹腔注射给予妊娠大鼠（EGF 组和 Dex 组），而生理盐水注射组作为阴性对照。在妊娠第 19 天通过剖腹产取出胎儿大鼠，然后从每组中随机选择 24 只胎儿大鼠。测量它们的体重，并通过免疫组织化学染色检测各组肺表面活性剂蛋白-A 和 -B（SP-A 和 SP-B）抗原。在光镜、光镜图像系统或电子显微镜下检查组织学结构。
各组均可检测到 SP-A 和 SP-B 的表达。EGF 和 Dex 组的 SP-A 和 SP-B 明显高于对照组（P<0.01）。图像分析显示，EGF 和 Dex 组的肺泡腔面积和肺泡间隔面积的相对值明显大于对照组（P<0.01），但两组之间无显著差异（P>0.05）。胎儿肺的超微结构特征显示，EGF 和 Dex 组含板层小体的Ⅱ型肺泡细胞数量明显增多。地塞米松组胎儿的平均体重小于对照组（（1.3192±0.0533）g，（1.3863±0.0373）g），但 EGF 组与对照组之间无显著差异（（1.3986±0.0730）g，（1.3863±0.0373）g）。
在妊娠第 16-18 天给母鼠注射 EGF 和 Dex 可促进早产胎儿肺的形态发生并增加表面活性剂水平。然而，母体用 Dex 处理而不是 EGF 处理会降低体重。
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