Semester

Summer

Date of Graduation

2022

Document Type

Thesis

Degree Type

MS

College

School of Medicine

Department

Exercise Physiology

Committee Chair

Paul Chantler

Committee Co-Chair

Mark Olfert

Committee Member

Mark Olfert

Committee Member

Eric Kelley

Abstract

Introduction: Electronic cigarettes (e-cigs) are being marketed as a healthier alternative to traditional cigarettes, yet the health consequences of e-cig usage (also called vaping) are still being investigated. E-cigs are easily customized for user preferences. For example, the choice of flavors, nicotine concentration, and/or the temperature (i.e., wattage) used to heat the e-liquid can be selected in many devices. Emerging evidence suggests that vaping during pregnancy impairs cerebral vascular function in rodent offspring. In this study, we sought to investigate the potential effects of changes to e-cig device wattage (i.e., 5W vs. 30W) with maternal vaping during pregnancy on vascular function in the postnatal life of offspring. Methods: Adult female Sprague Dawley rats were time-mated to allow for maternal ecig exposure beginning on gestation days 2-4 until birth. Maternal vaping occurred for 1 h/day, 5 days/wk using a whole-body chamber system. E-cig aerosol was generated using a D19 Joyetech atomizer with nicotine-free (0 mg/mL) 50:50 VG:PG e-liquid without flavoring. Puff topology was 83 ml with 5-sec puff duration. Pregnant dams were randomly assigned to control (air-exposed), e-cig 5W, or e-cig 30W exposure groups (n=5-6 dams/group). Offspring (1 male and 1 female, n=2/dam) were studied at 30-, 90, and 180-days after birth, where in vivo carotid pulse wave velocity (PWV, an index of arterial stiffness) was assessed using a VisualSonics Vevo 2100 ultrasound; thereafter, animals were euthanized and thoracic aortas were excised, cleaned, and cut into 2mm rings for wire myography (DMT, AD instruments). Aortic rings were mounted and warmed in aerated Krebs-Henseleit buffer solution, and vessel reactivity was measured using serial dilutions of methacholine [MCh; 10-9 to 10-5 M] and sodium nitroprusside [SNP; 10-9 to 10-5 M] to assess endothelial-dependent dilation (EDD) and endothelium-independent dilation (EID), respectively. Results: At 30-days, max aortic EDD was not different between either 5W (82±4%, mean±SEM) or 30W (89±2%) groups compared to controls (89±2%) (p>0.05); and no differences in PWV were seen between either 5W (2.6±0.2 m/s) or 30W (2.7±0.2 m/s) groups compared to controls (2.5±0.1 m/s) (p>0.05). At 90-days, max aortic EDD was lower with 30W (73±8%) (p0.05) groups compared to controls (94±2%); and PWV was elevated in 5W (3.5±0.2 m/s) and 30W (3.7±0.2 m/s) groups compared to controls (2.9±0.1 m/s) (pConclusion: These data show vaping during pregnancy is not safe and has long-lasting consequences on the vascular health of progeny. Further, they suggest that maternal vaping at both 5W and 30W device heat settings induces aortic endothelial dysfunction and arterial stiffness in offspring, which last throughout adolescence and adulthood.

Embargo Reason

Publication Pending

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