Pulmonary vascular abnormalities in experimentally induced congenital diaphragmatic hernia in rats

doi:10.1016/0022-3468(92)90385-K

Journal of Pediatric Surgery

Volume 27, Issue 7, July 1992, Pages 862-865

https://doi.org/10.1016/0022-3468(92)90385-K Get rights and content

Abstract

In infants with congenital diaphragmatic hernia (CDH), abnormalities of the pulmonary arteries are present consisting of increased medial wall thickness and decreased external diameter. This forms the morphological substrate for persistent pulmonary hypertension, one of the leading causes of the high mortality in these patients. To elucidate the significance of these abnormalities, experimental models are required that mimic as close as possible the human situation. In our rat model we are able to study the hypoplastic CDH lungs extensively. In this study we performed a histological evaluation of the pulmonary arterial bed in the control group and the nitrofen-treated group in which the latter was divided into two subgroups, CDH and normal diaphragm. We examined the newborn rats after perfusion of the pulmonary arteries with barium gelatine and subsequent fixation. At the level of the respiratory bronchioles significant differences in the vessels were found consisting of decreased external diameter and increased wall thickness as percentage of the external thickness in CDH lungs compared with controls. Abnormal muscularization of the peripheral branches of the CDH pulmonary arteries was also found. We concluded that the rat model strongly resembles the human situation concerning the arterial bed in the lungs.

References (20)

FWJ Hazebroek et al.
Congenital diaphragmatic hernia: The impact of preoperative stabilization. A prospective study in 13 patients
J Pediatr Surg
(1988)
RL Geggel et al.
Congenital diaphragmatic hernia: Arterial structural changes and persistent pulmonary hypertension after surgical repair
J Pediatr
(1985)
D Levin
Morphologic analysis of the pulmonary vascular bed in congenital left-sided diaphragmatic hernia
J Pediatr
(1978)
D Bohn et al.
Ventilatory predictors of pulmonary hypoplasia in congenital diaphragmatic hernia, confirmed by morphologic assessment
J Pediatr
(1987)
KC Pringle et al.
Creation and repair of diaphragmatic hernia in the fetal lamb: Lung development and morphology
J Pediatr Surg
(1984)
NS Adzick et al.
Correction of congenital diaphragmatic hernia in utero. IV. An early gestational fetal lamb model for pulmonary vascular morphometric analysis
J Pediatr Surg
(1985)
C Lau et al.
Teratogenic effects on cellular and functional maturation of the rat lung
Toxicol Appl Pharmacol
(1988)
R Tenbrinck et al.
Experimentally induced congenital diaphragmatic hernia in rats
J Pediatr Surg
(1990)
D Kluth et al.
Nitrofen-induced diaphragmatic hernia in rats: An animal model
J Pediatr Surg
(1990)
RL Geggel et al.
Effects of chronic in utero hypoxemia on rat neonatal pulmonary arterial structure
J Pediatr
(1986)

There are more references available in the full text version of this article.

Cited by (50)

Vitamin D improves pulmonary function in a rat model for congenital diaphragmatic hernia
2021, Archives of Biochemistry and Biophysics
Citation Excerpt :
Therefore, it is important to investigate these aspects in future translational research. Pulmonary vascular changes caused by CDH are thought to appear during the embryonic stage, although PH develops after birth [32,33]. Therefore, the prevention of pulmonary artery remodeling is likely to reduce the severity of PH after birth in patients with CDH.
A congenital diaphragmatic hernia (CDH) is an anomaly caused by defects in the diaphragm; the resulting limited thorax cavity in turn restricts lung growth (pulmonary hypoplasia). This condition is related to pulmonary hypertension. Despite advances in neonatal CDH therapy, the mortality for severe pulmonary hypoplasia remains high. Therefore, it is essential to establish prenatal therapeutic interventions. Vitamin D was reported to have beneficial effects on adult pulmonary hypertension. This study aims to evaluate the efficacy of prenatal vitamin D administration for CDH. First, serum 25-hydroxyvitamin D [25(OH)D] levels in umbilical cord blood were evaluated among CDH newborns. Second, Sprague Dawley rat CDH models were exposed to nitrofen on embryo day 9 (E9). Randomly selected rats in the nitrofen-treated group were infused with calcitriol from E9 to E21. Samples from CDH pups diagnosed after birth were used for lung weight measurements, blood gas analysis, and immunohistochemical analysis. Third, microarray analysis was performed to examine the effect of vitamin D on gene expression profiles in CDH pulmonary arterial tissues. Serum 25(OH)D levels in the umbilical cord blood of newborns who did not survive were significantly lower than those who were successfully discharged. Prenatal vitamin D showed no significant effect on CDH incidence or lung weight but attenuated alveolarization and pulmonary artery remodeling accompanied the improved blood gas parameters. Vitamin D inhibited several gene expression pathways in the pulmonary arteries of CDH rats. Our results suggest that prenatal vitamin D administration attenuates pulmonary vascular remodeling by influencing several gene pathways in CDH.
Platelet-derived growth factor inhibition-a new treatment of pulmonary hypertension in congenital diaphragmatic hernia?
2008, Journal of Pediatric Surgery
Increased pulmonary vascular resistance causing pulmonary artery hypertension is a major problem in the treatment of congenital diaphragmatic hernia with a strong association to mortality. We here report a patient with intractable pulmonary hypertension at 4 weeks of age unresponsive to conventional treatment. After administration of the platelet-derived growth factor (PDGF) receptor antagonist imatinib, pulmonary artery pressure gradually decreased to acceptable levels and the patient's clinical condition gradually improved.
Effects of prenatal vitamins A, E, and C on the hypoplastic hearts of fetal rats with diaphragmatic hernia
2005, Journal of Pediatric Surgery
Nitrofen induces heart hypoplasia together with congenital diaphragmatic hernia (CDH) in rats. Intracellular oxidative stress might be one of the mechanisms of action of the teratogen, and vitamin A has been shown to reverse in part these effects when administered simultaneously or shortly after it. This study aims at testing the hypothesis that vitamin A and other antioxidant vitamins, such as E and C, could improve myocardial development even when administered late in gestation, a likely useful period for prenatal medication.
Time-mated Sprague-Dawley female rats were exposed to either vehicle (control) or 100 mg of nitrofen (experimental) on day 9.5 of gestation. In 3 additional groups, the animals were exposed to vitamin A (total 15 000 IU), vitamin E (total 150 IU), or vitamin C (total 150 IU) on days 16, 17, and 18. The fetuses were recovered on day 21, and randomly selected hearts of those with CDH were processed for histologic studies (hematoxylin-eosin and periodic acid-Schiff stainings), DNA and protein contents, and ki-67 (proliferation) and terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling (apoptosis) studies. The differences among groups were assessed by analysis of variance with Bonferroni/Dunn post hoc tests and a threshold of significance of P < .05.
Nitrofen induced heart hypoplasia in terms of decreased heart/body weight, cell mass (less DNA and protein), and proportion of proliferating cells with increased apoptosis. Vitamin C alleviated weight hypoplasia and the 3 vitamins were able to restore cell mass and to reestablish near-normal figures of proliferation and apoptosis.
Antioxidant vitamins A, E, and C given late in gestation alleviate heart hypoplasia that accompanies CDH in the rat model. This timing suggests that the beneficial effects are exerted on the maturational phase of development.
Congenital diaphragmatic hernia: Searching for answers
2005, American Journal of Surgery
Citation Excerpt :
In addition, either right-sided or left-sided CDHs can be induced by varying the timing of nitrofen exposure. This animal model is associated with PH, pulmonary vascular abnormalities [8], and pulmonary immaturity [9]. The teratogenic model of CDH has been used extensively to study the embryologic origins of defects in diaphragm and lung development as well as for studies of prenatal treatments designed to improve lung growth and function.
Pulmonary hypoplasia and hypertension are the primary causes of morbidity and mortality in infants with congenital diaphragmatic hernia (CDH). At present, the origin of CDH and the causes of pulmonary hypoplasia and hypertension are unknown.
This article reviews the available published data regarding the origin of CDH and the pathogenesis of the associated pulmonary hypertension and hypoplasia. These investigations have employed human tissues as well as two types of CDH animal models.
Investigations performed to date have not yet provided definitive answers regarding the pathogenesis of CDH. However, they have yielded many new and exciting discoveries and several opportunities for intervention. Ongoing research should open new possibilities to improve the outcome for these unfortunate babies with CDH.
Differential effects of vitamin A on fetal lung growth and diaphragmatic formation in nitrofen-induced rat model
2005, Pulmonary Pharmacology and Therapeutics
Congenital diaphragmatic hernia (CDH) is associated with high neonatal mortality and morbidity due to pulmonary hypoplasia and pulmonary hypertension. Antenatal interventions have been developed in an attempt to reduce the unacceptable mortality rate of CDH. The pathogenesis of pulmonary hypoplasia is not fully understood. It is not clear whether the increase of lung growth would be necessary for diaphragmatic closure. Vitamin A is important for various aspects of lung development. Therefore, the aim of this study was to examine whether antenatal treatment with vitamin A can increase lung growth and reduce the incidence of CDH in a nitrofen-treated rat model. The animals were randomly assigned to four groups: control, vitamin A, nitrofen, and nitrofen/vitamin A (NIP/Vit A). The incidence of CDH in the NIP/Vit A group (54%) was markedly lower than that in the nitrofen-treated group (85%). Although lung weight was decreased in the nitrofen-treated and NIP/vitamin A groups, the fetal lung weight-to-body weight ratio was slightly increased in the NIP/vitamin A group, compared to the nitrofen-treated group. The mRNA levels of lung surfactant proteins were decreased in the NIP/vitamin A group. We conclude that antenatal treatment with vitamin A reduced the incidence of CDH without lung maturation in the nitrofen-induced rat model.
Nitrofen-Induced Congenital Diaphragmatic Hernia in Rat Embryo: What Model?
2004, Journal of Pediatric Surgery
The aim of this study was to investigate the natural history of congenital diaphragmatic hernia (CDH) in rat embryos with special attention to the pathomorphologic changes of diaphragm, liver, intestines, and lungs at various stages of embryonic development.
Pregnant Sprague-Dawley rats were given, via a gavage tube, 100 mg nitrofen (Wako Chemicals, Neuss, Germany) on day 10.5 of gestation. Fetuses were harvested by laparotomy on day 15.5, 16.5, 18, and 21. Anatomic study of the diaphragm, herniated viscera, and lungs was performed under stereoscope with special attention to the diaphragmatic defect.
CDH occurred in 44 embryos on right, in 10 on the left, and in 34 bilateral. In the youngest embryos, the small defect was located in the dorsomedial portion of the diaphragm very close to the aortic hiatus. During pregnancy, the defect enlarged progressively to occupy more than half of the affected hemidiaphragm on day 21. In all animals, regardless of their age and side of the defect, the liver was found inside the chest. The intrathoracic mass was formed by ingrown hepatic tissue originating from the dorsal surface of the intraabdominal liver. It appeared as an accessory liver lobe. The amount of intrathoracic liver increased rapidly. From around day 18, the thoracic portion of liver, when examined in sagittal plane, was bent forward and assumed an uncinate shape. The stomach and small bowel loops were displaced into the chest in the oldest examined fetuses. The first sign of reduction of size of the lung was seen in 16, 5-day old embryos, and at further stages of embryonic development the lung growth impairment strictly paralleled the ingrowth of the liver. The natural history of the right and left CDH were very similar. In fetuses with bilateral CDH, asymmetry regarding size of the defect and volume of intrathoracic hepatic mass was noted with larger defects on the left side in more than 60% of animals.
Pathogenesis of nitrofen-induced diaphragmatic defect in the rat embryo and CDH in the human fetus seem to differ significantly. Nitrofen induces a complex malformation of the embryonic diaphragm and the liver. CDH in rat embryo bears more resemblance to a model of space-occupying lesion than to human CDH. The induction of localized hepatic proliferation may be a result of disturbance of as yet unknown regulatory interaction between hepatic and mesenchymal diaphragmatic cells.

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^☆: Presented at the 38th Annual International Congress of the British Association of Paediatric Surgeons, Budapest, Hungary, July 24–26, 1991.

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Pulmonary vascular abnormalities in experimentally induced congenital diaphragmatic hernia in rats☆

Abstract

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