Change in somatostatin receptor expression after vascular injury

• Main Author: Chen, Jerry
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/8999

Somatostatin is an inhibitory neuroendocrine peptide that exerts its effects through 5 functionally distinct receptor subtypes (SSTR1-5). Somatostatin analogues have been shown to be effective in inhibiting intimal hyperplasia after balloon induced vascular injury. However, the exact SSTR subtype responsible for the inhibitory effect of somatostatin on intimal hyperplasia is unknown. Purpose'. To define the presence and abundance of the SSTR-2 subtype in a rat iliac balloon injury model of intimal hyperplasia. Methods'. Transaortic balloon injury of the rat iliac artery was carried out. Rats were sacrificed at 48 hours, 1 week and 1 month post injury, perfusion fixed and samples of iliac arteries were immunostained with antibodies against SSTR 1,2, and 3. Expression of SSTR-2 was confirmed by reverse transcriptase polymerase chain reaction (RT-PCR). The PCR product was sequenced to confirm its identity. Results: Immunocytochemical staining demonstrated the presence of SSTR2 on the intimal surfaces of normal and injured vessels. SSTR2-immunoreactivity was more prominent at 1 week and 1 month post injury compared with 48 hours post injury. There was no immunostaining with SSTR1 and SSTR3 antibodies. PCR results confirm elevated SSTR2 in injured arteries. Conclusion: SSTR2 is expressed on endothelial cells in normal and injured rat vessels. Its abundance in the injured vessel was increased up to 1 month post injury.