E Foster1, S Zhang, A M Kahn. 1. Division of Renal Diseases and Hypertension, Department of Medicine, The University of Texas Health Science Center, Houston Medical School, Houston, TX 77030, USA.
Abstract
AIM: Insulin resistance in patients is associated with increased atherosclerosis and arterial restenosis. It is thought that the concomitant hyperinsulinaemia exacerbates vascular disease because resistance to insulin-induced glucose disposal is associated with resistance to certain effects of insulin which inhibit, but with no resistance to other effects which promote, neointimal hyperplasia. We sought to determine the net effect of hyperinsulinaemia on neointimal hyperplasia in normal animals. METHODS: Rats were infused with or without insulin for 16 days and the carotid artery injured by balloon catheter on day 2. RESULTS: Steady-state serum insulin concentrations were 0.56 +/- 0.04 and 1.25 +/- 0.05 nm for control and hyperinsulinaemic rats respectively (p < 0.01). Systolic blood pressures, weights and serum glucose levels were not affected by hyperinsulinaemia. Fourteen days after injury, the neointima-to-media area ratio was 0.72 +/- 0.07 and 1.39 +/- 0.15 for control and hyperinsulinaemic rats respectively (p < 0.05). Media area was unaffected by hyperinsulinaemia. CONCLUSIONS: The effects of hyperinsulinaemia which promote neointimal hyperplasia after balloon injury of rat carotid artery predominate over the effects which inhibit it even in normal animals.
AIM: Insulin resistance in patients is associated with increased atherosclerosis and arterial restenosis. It is thought that the concomitant hyperinsulinaemia exacerbates vascular disease because resistance to insulin-induced glucose disposal is associated with resistance to certain effects of insulin which inhibit, but with no resistance to other effects which promote, neointimal hyperplasia. We sought to determine the net effect of hyperinsulinaemia on neointimal hyperplasia in normal animals. METHODS:Rats were infused with or without insulin for 16 days and the carotid artery injured by balloon catheter on day 2. RESULTS: Steady-state serum insulin concentrations were 0.56 +/- 0.04 and 1.25 +/- 0.05 nm for control and hyperinsulinaemic rats respectively (p < 0.01). Systolic blood pressures, weights and serum glucose levels were not affected by hyperinsulinaemia. Fourteen days after injury, the neointima-to-media area ratio was 0.72 +/- 0.07 and 1.39 +/- 0.15 for control and hyperinsulinaemic rats respectively (p < 0.05). Media area was unaffected by hyperinsulinaemia. CONCLUSIONS: The effects of hyperinsulinaemia which promote neointimal hyperplasia after balloon injury of rat carotid artery predominate over the effects which inhibit it even in normal animals.
Authors: R S Mughal; J L Scragg; P Lister; P Warburton; K Riches; D J O'Regan; S G Ball; N A Turner; K E Porter Journal: Diabetologia Date: 2010-05-12 Impact factor: 10.122
Authors: Subramanyam N Murthy; Sergiy Sukhanov; Jennifer McGee; Joel A Greco; Surabhi Chandra; Patrice Delafontaine; Philip J Kadowitz; Dennis B McNamara; Vivian A Fonseca Journal: Mol Cell Biochem Date: 2009-04-10 Impact factor: 3.396