To clarify the mechanism underlying increased endothelin-1 release in diabetic rats, we examined its release from thoracic aortas obtained from streptozotocin-induced diabetic rats. The methoxamine-induced contraction was significantly inhibited by BQ-123 plus BQ-788 (specific antagonists for ETA and ETB receptors) in diabetic, but not control rats. Preincubation with phosphoramidon also inhibited the methoxamine-induced contraction in diabetic but not control rats. The expression of prepro endothelin-1 mRNA was significantly enhanced in aortas from streptozotocin-induced diabetic rats. These results suggest that the increases in the basal and α-agonist-induced release of endothelin-1 in the diabetic state may be due to an overexpression of the mRNA for prepro endothelin-1.
- PreproET-1 mRNA
- Thoracic aorta
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience