Endothelial cell injury in venule and capillary induced by contrast ultrasonography.
The aim of the present study was to test the hypothesis that microvascular endothelial cells (EC) are subject to the bioeffects induced by contrast ultrasound (US) because of their proximity to the circulating microbubbles. We examined EC injury in each microvessel section (arteriole, capillary or venule) in rat mesenteries among the following five groups: three controls (sham operation, microbubble injection alone, US exposure with saline injection), and two contrast-US groups (US exposure at a 1-Hz or 30-Hz frame rate with microbubble injection). Propidium iodide (PI), a fluorescent indicator of cell injury, was employed to visualize impaired EC. PI-positive nuclei were equally few among the three controls. Contrast-US increased PI-positive cells in capillaries (1-Hz frame rate, 2.4 +/- 2.2 cells per 0.1-mm vessel length, p = 0.09; 30-Hz frame rate, 4.3 +/- 1.8 cells, p < 0.01) and in venules (1-Hz frame rate, 4.1 +/- 2.5 cells, p < 0.05; 30-Hz frame rate, 13.8 +/- 3.6 cells, p < 0.01) compared with sham operation (0.10 +/- 0.22 cells). The finding indicates that diagnostic contrast US potentially causes EC injury, particularly in venules and capillaries.
First Department of Integrated Medicine, Omiya Medical Center, Jichi Medical School, Saitama, Japan.
Nobuhiko
N
Kobayashi
Takanori
T
Yasu
Satoshi
S
Yamada
Nobuki
N
Kudo
Masatoshi
M
Kuroki
Masanobu
M
Kawakami
Kunio
K
Miyatake
Muneyasu
M
Saito
D000704:Analysis of Variance; D000818:Animals; D004396:Coloring Agents; D003287:Contrast Media / Q000009:adverse effects*; D004730:Endothelium, Vascular / Q000293:injuries*; D004867:Equipment Design; D008297:Male; D008643:Mesentery / Q000098:blood supply*; D008833:Microcirculation; D011134:Polysaccharides / Q000009:adverse effects*; D011419:Propidium; D051381:Rats; D017208:Rats, Wistar; D014463:Ultrasonography / Q000379:methods*
D004396:Coloring Agents; D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508; D011419:Propidium