Repeated measurements of fasting glucose levels, and blood flow and arterial pulse by laser Doppler flowmetry (LDF) were made at pre-exposure, and at 0, 4, and 8 wk after exposure to silica. Animals were fasted for 12−15 hours overnight (water available ad libitum) and fasting blood glucose was measured the next morning. The rat tail was sterilized with alcohol wipe then warmed for 45 s using a heating pad. An automatic lancet (Freestyle Lancing Device, 28-gauge sterile lancet, Abbott Laboratories; Alpharetta, GA) was used to prick the tail approximately 0.5 in. from the tip to obtain a small droplet of blood and glucose was measured with a hand-held glucometer (Freestyle Freedom Lite Blood Glucose Meter, Abbott Laboratories). Food was returned, along with water, and was available ad libitum.
LDF, a peripheral non-invasive procedure, was used to measure changes in rat tail arterial blood flow and arterial pulse. These measures were made in unfasted animals placed in Broome-style restrainers and recorded over a 15-min period. Mean blood flow was calculated and analyzed. Time series analyses were performed on the blood flow data (fast Fourier transform analysis, FFT) and two primary peaks in blood flow were identified, at 0.88–1 and 0.2 – 0.4 Hz.
LDF, a peripheral non-invasive procedure, was used to measure changes in rat tail arterial blood flow and arterial pulse. These measures were made in unfasted animals placed in Broome-style restrainers and recorded over a 15-min period. Mean blood flow was calculated and analyzed. Time series analyses were performed on the blood flow data (fast Fourier transform analysis, FFT) and two primary peaks in blood flow were identified, at 0.88–1 and 0.2 – 0.4 Hz.