Tissue distribution and localization of natriuretic peptide receptor subtypes in stroke-prone spontaneously hypertensive rats

Abstract

Objective 

To investigate tissue distribution and localization of the natriuretic peptide receptor (NPR) subtypes' messenger RNA (mRNA) and to compare their expression between stroke-prone spontaneously hypertensive rats (SHR-SP) and Wistar–Kyoto (WKY) rats.

Methods 

Total RNA was extracted from organs of SHRSP and WKY rats aged 13 weeks. The mRNA level was examined by RNase protection assay. The localization of the transcripts was determined by in-situ hybridization.

Results 

In SHR-SP aged 13 weeks, NPR-A was expressed most abundantly in the adrenal gland, lung and aorta, in that order. NPR-B was expressed highly in the uterus and ovary, and also in the lung, adrenal, and brain. NPR-C was expressed predominantly in the atrium and mesentery, less so in the lung, vein, and kidney. In the adrenal gland, NPR-A was expressed mainly in zona glomerulosa cells. In the atrium, NPR-C was expressed throughout the wall. In the mesentery, NPR-C mRNA was detected mainly in adipocytes. In the kidney, NPR-C was found predominantly in podocytes. Whereas the levels of expression of NPR subtypes in most tissues examined did not differ between SHR-SP and WKY rats, the NPR-C mRNA level was significantly greater in the kidneys of SHR-SP than it was in those of WKY rats.

Conclusions 

These results indicated that each NPR subtype had a distinct tissue distribution pattern and that the expression of NPR-C in the kidneys of SHR-SP was greater than that in the kidneys of WKY rats.