Pressure-Induced Upregulation of Preproendothelin-1 and Endothelin B Receptor Expression in Rabbit Jugular Vein In Situ

Abstract

Abstract-Upregulation of endothelin-1 (ET-1) synthesis in venous bypass grafts in response to arterial levels of blood pressure may play a major role in graft failure. To investigate this hypothesis, isolated segments of the rabbit jugular vein were perfused at physiological (0 to 5 mm Hg) and nonphysiological (20 mm Hg) levels of intraluminal pressure.As judged by reverse transcription-polymerase chain reaction analysis (mRNA level), neither endothelin-converting enzyme nor endothelin A receptor expression appeared to be pressure sensitive. In contrast, there was a profound and time-dependent increase in endothelial prepro-ET-1 mRNA and intravascular ET-1 abundance (by ELISA) as well as in smooth muscle endothelin B receptor mRNA and functional protein (by superfusion bioassay) on raising the perfusion pressure from 5 to 20 mm Hg, but not from 0 to 5 mm Hg, for up to 12 hours. Video microscopy analysis revealed that the segments were distended by 75% at 5 mm

Deformation-induced endothelin B receptor-mediated smooth muscle cell apoptosis is matrix-dependent

“…8,9 EF-1 expression was not pressure-sensitive as previously demonstrated. 8,9 Immunohistochemistry Formaldehyde-fixed sections of the carotid artery and jugular vein were embedded in paraffin blocks of which 7 mm thick sections were cut.…”

“…8,9 EF-1 expression was not pressure-sensitive as previously demonstrated. 8,9 Immunohistochemistry Formaldehyde-fixed sections of the carotid artery and jugular vein were embedded in paraffin blocks of which 7 mm thick sections were cut. After paraffin removal (boiling of the glass-fixed sections six times for 5 min in 10 mmol/L sodium citrate, pH 6.0), they were inactivated in 10 mmol/L Tris buffer, pH 7.6 containing 3% (v/v) hydrogen peroxide followed by blocking of non-specific binding sites for 20 min at room temperature with 10% (w/v) bovine serum albumin in Hank's balanced salt solution (Life Technologies).…”

“…8 To test whether the peptide is involved in the early phases of pressure-induced vascular remodelling, we have set up an in situ model in which isolated segments of the carotid artery and jugular vein of the rabbit are perfused at different levels of intraluminal pressure. references 8,9 ) a new series of experiments was performed both with isolated perfused segments of the carotid artery and jugular vein of the rabbit (Figure 1). In both types of blood vessels prepro-ET-1 expression and that of the ET B -R were up-regulated in response to perfusion at a supra-physiological pressure of 160 and 20 mm Hg, respectively, for 6 h. ET A -R expression and that of endothelin-converting enzyme 1 (ECE-1), on the other hand, appeared to be pressure-insensitive.…”

Deformation-induced endothelin B receptor-mediated smooth muscle cell apoptosis is matrix-dependent

“…ET-1 is not only a powerful co-mitogen, 13 its synthesis by the endothelium also is strongly up-regulated by (blood) pressureinduced distension of the vessel wall. 9 In addition, ET B -R mRNA abundance in the SMC is markedly increased under these conditions.…”

“…8,9 ) a new series of experiments was performed both with isolated perfused segments of the carotid artery and jugular vein of the rabbit (Figure 1). In both types of blood vessels prepro-ET-1 expression and that of the ET B -R were up-regulated in response to perfusion at a supra-physiological pressure of 160 and 20 mm Hg, respectively, for 6 h. ET A -R expression and that of endothelin-converting enzyme 1 (ECE-1), on the other hand, appeared to be pressure-insensitive.…”