These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Impaired paracrine effect of endothelin-1 on vascular smooth muscle in streptozotocin-diabetic rats.
    Author: Wu SQ, Tang F.
    Journal: Cardiovasc Res; 1998 Sep; 39(3):651-6. PubMed ID: 9861308.
    Abstract:
    OBJECTIVE: This study was to examine the effect of streptozotocin-induced diabetes on endothelin-1 and its receptors in the mesenteric artery and in the thoracic aorta. METHODS: Diabetes was induced in SD rats by streptozotocin. Insulin was given subcutaneously. Endothelin-1 levels in the plasma, thoracic aorta and mesenteric artery were measured using radioimmunoassay. The Bmax and Kd values of endothelin-1 receptors in the mesenteric artery and in the thoracic aorta were analyzed using Scatchard plot analysis. Preproendothelin mRNA levels were examined using RT-PCR. RESULTS: Endothelin-1 levels in the mesenteric artery (83.6 +/- 6.9 pg/mg protein) and in the thoracic aorta (73.9 +/- 8.2 pg/mg protein) increased in 2 week diabetic rats compared with both control (51.8 +/- 5.3, 46.3 +/- 5.9 pg/mg protein) and insulin treated rats (65.6 +/- 8.1, 48.1 +/- 4.2 pg/mg protein) but not in 4 week diabetic rats. There was no change in plasma endothelin-1 levels in these diabetic rats. The RT-PCR results indicated that preproendothelin mRNA levels in the mesenteric artery (0.38 +/- 0.02 vs 0.52 +/- 0.05 units) and in the thoracic aorta (0.45 +/- 0.06 vs 0.62 +/- 0.03 units) decreased in 4 week diabetic rats but not in 2 week diabetic rats. A significant increase in Kd and Bmax of endothelin receptors in the mesenteric artery and in the thoracic aorta was observed in both 2 week (about 70%) and 4 week (80-85%) diabetic rats. Insulin replacement reversed the effects of diabetes on endothelin-1 peptide contents, preproendothelin mRNA levels and the binding activity in the blood vessels. CONCLUSION: Increased endothelin peptide content with no change in mRNA or decreased mRNA levels with no change in peptide content together with increased receptor binding sites and affinities might imply a decrease in endothelin release and therefore an impaired paracrine effect of endothelin on vascular smooth muscles in these STZ-diabetic rats.
    [Abstract] [Full Text] [Related] [New Search]