Document


Title

Acute peat smoke inhalation sensitizes rats to the postprandial cardiometabolic effects of a high fat oral load
Document Type: Journal Article
Author(s): Brandi L. Martin; Leslie C. Thompson; Yongho Kim; Wanda Williams; Samantha J. Snow; Mette C. Schladweiler; Pamela Phillips; Charly King; Judy Richards; Najwa Haykal-Coates; Mark A. Higuchi; M. Ian Gilmour; Urmila P. Kodavanti; Mehdi S. Hazari; Aimen K. Farraj
Publication Year: 2018

Cataloging Information

Keyword(s):
  • air pollution
  • Cardiovascular
  • exposure
  • health
  • health impacts
  • metabolic rate
  • peat fires
Region(s):
Record Maintained By:
Record Last Modified: November 20, 2019
FRAMES Record Number: 59037

Description

Wildland fire emissions cause adverse cardiopulmonary outcomes, yet controlled exposure studies to characterize health impacts of specific biomass sources have been complicated by the often latent effects of air pollution. The aim of this study was to determine if postprandial responses after a high fat challenge, long used clinically to predict cardiovascular risk, would unmask latent cardiometabolic responses in rats exposed to peat smoke, a key wildland fire air pollution source. Male Wistar Kyoto rats were exposed once (1 h) to filtered air (FA), or low (0.36 mg/m3 particulate matter) or high concentrations (3.30 mg/m3) of peat smoke, generated by burning peat from an Irish bog. Rats were then fasted overnight, and then administered an oral gavage of a HF suspension (60 kcal% from fat), mimicking a HF meal, 24 h post-exposure. In one cohort, cardiac and superior mesenteric artery function were assessed using high frequency ultrasound 2 h post gavage. In a second cohort, circulating lipids and hormones, pulmonary and systemic inflammatory markers, and circulating monocyte phenotype using flow cytometry were assessed before or 2 or 6 h after gavage. HF gavage alone elicited increases in circulating lipids characteristic of postprandial responses to a HF meal. Few effects were evident after peat exposure in un-gavaged rats. By contrast, exposure to low or high peat caused several changes relative to FA-exposed rats 2 and 6 h post HF gavage including increased heart isovolumic relaxation time, decreased serum glucose and insulin, increased CD11 b/c-expressing blood monocytes, increased serum total cholesterol, alpha-1 acid glycoprotein, and alpha-2 macroglobulin (p = 0.063), decreased serum corticosterone, and increased lung gamma-glutamyl transferase. In summary, these findings demonstrate that a HF challenge reveals effects of air pollution that may otherwise be imperceptible, particularly at low exposure levels, and suggest exposure may sensitize the body to mild inflammatory triggers.

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Citation:
Martin, Brandi L.; Thompson, Leslie C.; Kim, Yongho; Williams, Wanda; Snow, Samantha J.; Schladweiler, Mette C.; Phillips, Pamela; King, Charly; Richards, Judy; Haykal-Coates, Najwa; Higuchi, Mark A.; Gilmour, M. Ian; Kodavanti, Urmila P.; Hazari, Mehdi S.; Farraj, Aimen K. 2018. Acute peat smoke inhalation sensitizes rats to the postprandial cardiometabolic effects of a high fat oral load. Science of The Total Environment 643:378-391.