In:
The Journal of Physiology, Wiley, Vol. 581, No. 3 ( 2007-06-15), p. 1173-1181
Abstract:
Nitric oxide (NO) and endothelin‐1 (ET‐1) are known to play a major role in renal and vascular pathophysiology and exhibit a close interaction with ET‐1, stimulating NO production; NO in turn inhibits ET‐1 expression. Our objectives were (1) to establish a novel transgenic mouse model facilitating ET‐1 expression assessment in vivo , (2) to validate this model by assessing prepro‐ET‐1 promoter activity in mice embryos by means of our novel model and comparing expression sites to well‐established data on ET‐1 in fetal development and (3) to investigate renal ET–NO interaction by assessing prepro‐ET‐1 promoter activity in different structures of the renal cortex in the setting of blocked NO synthases via l ‐NAME administration. We established transgenic mice carrying a lacZ reporter gene under control of the human prepro‐ET‐1 gene promoter sequence (8 kb of 5′ sequences). Bluo‐Gal staining of tissue sections revealed intracellular blue particles as indicators of prepro‐ET‐1 promoter activity. In mouse embryos, we detected high prepro‐ET‐1 promoter activity in the craniofacial region, as well as in bone and cartilage consistent with the literature. In order to investigate the interaction of ET‐1 and NO in the kidney in vivo , transgenic mice at the age of 3–4 months were treated with a single dose of the NO synthase inhibitor l ‐NAME (25 mg (kg bw) −1 i.p. ) 12 h before kidney removal. Bluo‐Gal staining of kidney sections revealed intracellular blue particles as indicators of prepro‐ET‐1 promoter activity in tubular and vascular endothelium and glomerular cells. Particle count was closely correlated to kidney tissue ET‐1 content ( R = 0.918, P 〈 0.001). Comparison of counts revealed an increase by 135 ± 53% in l ‐NAME treated ( n = 12) compared to non‐treated mice ( n = 10, P = 0.001). Cell‐type specific evaluation revealed an increase of 136 ± 51% in tubular ( P = 0.001) and 105 ± 41% in glomerular cells ( P = 0.046), but no significant increase in vascular endothelium. In conclusion, our study revealed a close interaction of renal endothelin and the NO system in a cell‐type specific manner. Our new transgenic model provides a unique opportunity to analyse regulation of the ET system on a cellular level in vivo .
Type of Medium:
Online Resource
ISSN:
0022-3751
,
1469-7793
DOI:
10.1113/jphysiol.2007.131201
Language:
English
Publisher:
Wiley
Publication Date:
2007
detail.hit.zdb_id:
1475290-6
SSG:
12
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