title: Endothelial cell regrowth and morphology after balloon catheter injury of alloxan-induced diabetic rabbits.
abstract: Neointimal thickening after catheter injury has been reported to be influenced by the integrity of the vascular endothelium. We have previously shown that neointimal thickening is significantly reduced in alloxan-induced diabetic New Zealand White rabbits after catheter injury compared with euglycemic rabbits. In the present study, it was hypothesized that endothelial cell regrowth, morphology, and endothelium-dependent vasoreactivity after catheter injury are improved in the diabetic rabbit (glucose >/=400 mg/dl) compared with the euglycemic rabbit. Two weeks after catheter injury, the percent endothelial regrowth was significantly increased in diabetic animals compared with euglycemic animals (32.1 +/- 2 and 15.6 +/- 1, respectively; P < 0.05). The endothelial cell morphology analyzed by scanning electron microscopy was also restored 2 wk after catheter injury in thoracic aortas from the diabetic animals compared with vessels from euglycemic animals. Endothelium-dependent relaxation to ACh in vessels from diabetic and euglycemic rabbits was attenuated 2 wk after injury, and, although improved by 4 and 8 wk, relaxation remained significantly depressed. These results suggest that endothelial cell regrowth and morphology in diabetic animals was improved compared with euglycemic animals; however, endothelium-dependent vasoreactivity remained impaired. Thus the attenuated neointimal thickening seen in the diabetic rabbit may be a function of the rate and degree of regrowth rather than the normalization of ACh-induced relaxation.
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: N K
authors.initials: NK
authors.lastname: Schiller
authors.forename: A M
authors.initials: AM
authors.lastname: Timothy
authors.forename: I L
authors.initials: IL
authors.lastname: Chen
authors.forename: J C
authors.initials: JC
authors.lastname: Rice
authors.forename: D L
authors.initials: DL
authors.lastname: Akers
authors.forename: P J
authors.initials: PJ
authors.lastname: Kadowitz
authors.forename: D B
authors.initials: DB
authors.lastname: McNamara
mesh_terms: D000818:Animals; D002404:Catheterization / Q000009:adverse effects*; D002455:Cell Division; D003921:Diabetes Mellitus, Experimental / Q000473:pathology* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000293:injuries* / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D011817:Rabbits