Acute Eucalyptus Smoke Inhalation Sensitizes Rats to the Postprandial Effects of a High Carbohydrate Meal

Previous studies have shown that air pollution exposure primes body systems to heightened responses to everyday activities that stress the cardiovascular (CV) system. The goal of this study was to investigate the impacts of a one-time exposure to eucalyptus smoke (ES) on the postprandial CV effects after a single high carbohydrate (HC) challenge, a cardiometabolic stressor long used to predict CV risk. Three-month-old male Sprague Dawley rats were exposed once (1 hr) to filtered air (FA) or ES (700 µg/m3 fine particulate matter), a key wildland fire air pollution source, generated by burning eucalyptus in a quartz tube furnace. Rats were then fasted for six hours the following morning, and subsequently administered an oral gavage of either water or a HC suspension (70 kcal% from carbohydrate), mimicking a HC meal, one day post-exposure. Two hours post gavage, cardiac and superior mesenteric artery function, circulating lipids and hormones, and pulmonary and systemic inflammatory markers were assessed. ES inhalation alone caused minimal responses compared to control animals. HC gavage alone caused an increase in glucose, serum interleukin (IL)-13, and keratinocyte chemoattractant (KC)/growth-regulated oncogene (KC-GRO) compared to water. By contrast, only ES-exposed and HC-challenged animals had an increase in serum IL-4 and IL-6, and increased aortic pressure compared to FA-exposed animals that received water. In summary, exposure to a model wildfire air pollution source modifies the response to a HC challenge and suggests that exposure sensitizes the body to inflammatory triggers.Master of Science in Public Healt