Attenuated insulin induced dilation in coronary arteries from obesity resistant and obesity prone high fat fed rats (1071.6)

Abstract

The purpose of this study was to compare physiologic, metabolic and microvascular complications in obesity resistant (OR) and obesity prone (OP) rats fed a high fat (HF) diet. 8 week old male rats were fed a diet containing 45% kcal saturated fat for 42 weeks. Blood pressure was measured by telemetry. Reactivity of small (75 ‐ 150 μm intraluminal diameter) coronary arteries was evaluated. Body weights were 504±7, 669±25*, 685±8*, and 924±39* grams for OR chow, OR HF, OP chow OP HF rats, respectively. Blood pressure was increased in OP rats on control diet (121.5 ± 4.3mmHg*) and further increased with HF diet (129.7 ± 2.4mmHg*), compared to OR rats on control (98.3 ± 4.3mmHg) or HF diet (99.5 ± 3.1mmHg). Glucose clearance was impaired in high fat fed OR and OP rats. Insulin mediated relaxation of coronary arteries from HF fed OR and OP rats was impaired (% relaxation to 100 ng/ml: OR chow = 37.1 ± 15, OR HF = 4.6 ± 5.3, OP chow = 29.3 ± 6.6 and OP HF = 7.6 ± 2.3). Acetylcholine (ACh)‐mediated relaxation of coronary arteries from HF fed rats was impaired (%relaxation to 10 μM Ach: OR chow=67 ± 10, OR HF = 36±12*, OP chow = 41±8*, and OP HF = 22±6*). Sodium nitroprusside (SNP) responses were not altered. *p<0.05 vs OR chow diet. These studies indicate that HF diet augments metabolic and microvascular complications in obesity prone rats.Grant Funding Source: Supported by VA Merit to Dr. Oltman