[Differences of Angiotensin II receptor expression between systemic and pulmonary circulation in children with left-to-right shunt congenital cardiac lesions].
OBJECTIVE
It has been shown that angiotensin converting enzyme inhibitors (ACEI) can reduce the ratio of pulmonary and systemic circulation blood flow (Qp/Qs) and thus decrease the blood flow of left-to-right shunt in children with left-to-right shunt congenital cardiac lesions. This suggests that there are differences in the expression of Angiotensin II receptors between systemic and pulmonary circulation. This study aimed to explore the differences of Angiotensin II receptors type 1 and type 2 (AT1 and AT2 receptors) expression between systemic and pulmonary circulation in children with left-to-right shunt congenital cardiac lesions.


METHODS
Lung and skeletal muscular tissues were obtained from 20 children with left-to-right shunt congenital cardiac lesions by biopsy during operation. The specimens were stained by immunohistochemistry techniques for AT1 and AT2 receptors. The technique of morphometric analysis was used to measure the immunoreactivity of AT1 and AT2 receptors (expressed by IOD values) of pulmonary, skeletal muscular and pleural small vascular wall the diameter of which was 15-100 microm.


RESULTS
The immunoreactivities of AT1 and AT2 receptors of pulmonary small vascular walls [(124 +/- 95)x10(3) and (85 +/- 62)x10(3) respectively] were significantly lower than those of skeletal muscular [(219 +/- 156)x10(3) and (155 +/- 139)x10(3) respectively] and those of pleural small vascular walls [(279 +/- 191)x10(3) and (175 +/- 128)x10(3) respectively] in children with left-to-right shunt congenital cardiac lesions (P < 0.05).


CONCLUSIONS
The expression of AT1 and AT2 receptors in small vascular walls of systemic circulation was higher than that of pulmonary circulation in children with left-to-right shunt congenital cardiac lesions.
Qiao
Li-Na
LN
Department of Pediatrics, West China Second Hospital, Sichuan University, Chengdu 610041, China. iaqiao@163.com
An
Qi
Q
Zhou
Tong-Fu
TF
Zhu
Qi
Q
Guo
Yi-Hong
YH
Wang
Wen-Dong
WD
D002648:Child; D002675:Child, Preschool; D005260:Female; D006330:Heart Defects, Congenital / Q000097:blood*; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D011652:Pulmonary Circulation; D044140:Receptor, Angiotensin, Type 1 / Q000097:blood*; D044139:Receptor, Angiotensin, Type 2 / Q000097:blood*
D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2