Progression of Diabetic Capillary Occlusion: A Model
Fig 13
(CASE1) cellular oxygen distribution over time.
Fraction of cells in each 4 mmHg oxygen bin is shown for the normal condition and 3 additional times. The distribution of oxygen tension within all cells exhibited an essentially unimodal shape under the normal condition (normal-red bars) where most cells had oxygen tensions of 10 to 25 mmHg, a small portion of cells located near vessels had higher levels ranging from 35 to 40 mmHg and no cells had an oxygen tension less than 4 mmHg O2. Capillary occlusions induced by VEGF gradually altered the distribution (week 0-blue bars, week 72-yellow bars, week 124-cyan bars). An increasing number of cells turned hypoxic. The broad peak of cells at moderate levels of oxygen decreased and broadened with more cells both at lower oxygen levels with each successive interval and more cells from about 25–30 mmHg in each successive interval. The cell oxygenation distribution gradually morphs from a unimodal distribution to a bimodal oxygenation distribution. Inset figure shows a comparison between normal condition and week 124 using a line-connecting-dot presentation, with finer oxygen tension spacing between two consecutive data points. The inset figure also strikingly shows the transition from unimodal to bimodal distribution as well as peak decreasing and broadening pattern at moderate levels.