title: Differential coronary resistance microvessel remodeling between type 1 and type 2 diabetic mice: impact of exercise training.
abstract: The goals of the present study were to compare coronary resistance microvessel (CRM) remodeling between type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) mice, and to determine the impact of aerobic exercise training on CRM remodeling in diabetes. Eight week old male mice were divided into T1DM: control sedentary (Control-SD), T1DM sedentary (T1DM-SD) induced by streptozotocin, and T1DM exercise trained (T1DM-TR); T2DM: control sedentary (Db/db-SD), T2DM sedentary (db/db-SD), and T2DM trained (db/db-TR). Aerobic exercise training (TR) was performed on a mouse treadmill for 8weeks. CRMs were isolated and mounted on a pressure myograph to measure and record vascular remodeling and mechanics. CRM diameters, wall thickness, stress-strain, incremental modulus remained unchanged in T1DM-SD mice compared to control, and exercise training showed no effect. In contrast, CRMs isolated from db/db-SD mice exhibited decreased luminal diameter with thicker microvascular walls, which significantly increased the wall:lumen ratio (Db/db-SD: 5.8±0.3 vs. db/db-SD: 8.9±0.7, p<0.001). Compared to db/db-SD mice, coronary arterioles isolated from db/db-TR mice had similar internal diameter and wall thickness, while wall:lumen ratio (6.8±0.2, p<0.05) and growth index (db/db-SD: 16.2 vs. db/db-TR: 4.3, % over Db/db) were reduced. These data show that CRMs undergo adverse inward hypertrophic remodeling only in T2DM, but not T1DM, and that aerobic exercise training can partially mitigate this process.
authors.affiliation: Center for Cardiovascular and Pulmonary Research, The Heart Center, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA. aaron.trask@nationwidechildrens.org
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Trask
authors.forename: Maria A
authors.initials: MA
authors.lastname: Delbin
authors.forename: Paige S
authors.initials: PS
authors.lastname: Katz
authors.forename: Angelina
authors.initials: A
authors.lastname: Zanesco
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Lucchesi
mesh_terms: D000818:Animals; D003331:Coronary Vessels / Q000378:metabolism / Q000473:pathology; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology / Q000628:therapy*; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology / Q000628:therapy*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology / Q000628:therapy*; D005081:Exercise Therapy / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D055806:Microvessels / Q000378:metabolism / Q000473:pathology; D010805:Physical Conditioning, Animal / Q000502:physiology; D013311:Streptozocin
chemical_list: D013311:Streptozocin