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Updated: Apr 17, 2026

A Chronic High-Intensity Interval Training and Diet-Induced Obesity Model to Maximize Exercise Effort and Induce Physiologic Changes in Rats
Published on: April 28, 2023
Cardiovascular, metabolic, and coronary dysfunction in high-fat-fed obesity-resistant/prone rats
Brian L Dake1, Christine L Oltman
1Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa and the Iowa City Veterans Affairs Health Care System, Iowa City, Iowa, USA.
Objective:
Obesity is a global epidemic leading to several comorbidities including diabetes and cardiovascular disease. The hypothesis that the genetic background of the obesity-prone rat (OP) predisposes to physiologic, metabolic, and microvascular dysfunction which is exacerbated by a diet high in saturated fats was tested.
Methods:
Male OP and obesity-resistant (OR) rats were fed either a diet containing 10% (chow) or 45% kcal fat (HF) for 42 weeks.
Results:
Weight of OP rats was greater than OR rats by 8 weeks on both diets. Blood pressure was increased in OP rats on chow and further augmented by HF diet compared to OR rats on similar diets. In contrast to weight and blood pressure, glucose clearance was similar in OR and OP rats on chow and impaired in both models on HF diet. Relaxation to acetylcholine was attenuated in OP rats compared to OR rats by 8 weeks and remained reduced throughout the study. A longer period of time was required to observe vascular dysfunction in HF-fed OR rats.
Conclusions:
When compared to OR rats, OP rats are prone to develop not only greater obesity but also hypertension and vascular dysfunction on a normal diet which is further augmented with HF diet.

