This research was supported by NHLBI Grant HL 10881.
An In-Vivo Analysis of Capillary Stasis and Endothelial Apoptosis in a Model of Hypertension
Article first published online: 26 JAN 2010
Volume 14, Issue 8, pages 793–804, November-December 2007
How to Cite
Tran, E. D. and Schmid-Schönbein, G. W. (2007), An In-Vivo Analysis of Capillary Stasis and Endothelial Apoptosis in a Model of Hypertension. Microcirculation, 14: 793–804. doi: 10.1080/10739680701419992
- Issue published online: 26 JAN 2010
- Article first published online: 26 JAN 2010
- Received 26 April 2007; accepted 26 April 2007.
- endothelial cell;
- annexin V;
- propidium iodide;
- in-vivo microscopy;
- time lapse photography;
- spontaneously hypertensive rat;
- Wistar Kyoto rat
Objective: Recent evidence suggests endothelial apoptosis may be a mechanism for capillary rarefaction in hypertensives. The objective of this study was to examine the early phase of endothelial apoptosis and capillary blood flow in the spontaneously hypertensive rat (SHR) and the normotensive Wistar-Kyoto (WKY) rat.
Methods: Since hypertension in SHR is dependent on glucocorticoids, the animals were treated with dexamethasone (DEX), by intraperitoneal injection and then by superfusion on exposed mesentery. Selected capillaries were continuously observed. Annexin V and propidium iodide were used to detect apoptosis.
Results: Without central pressure reduction, permanent capillary stasis was initiated by the entrapment of leukocytes at the location of an endothelial cell that had platelets attached to it. Apoptosis of the endothelial cell was followed by apoptosis in other endothelial cells of the obstructed capillary. The incidence of stasis and total cell death in WKY+DEX were higher than WKY, whereas there were no differences between SHR+DEX and SHR. Blockade of the lectin domain of L-selectin or a platelet membrane adhesion molecule (glycoprotein IIb/IIIa) blocked the development of stasis.
Conclusions: Glucocorticoid facilitates cell death and microvessel stasis. Immobilized platelets and leukocytes play a central role in capillary stasis, which leads to progression of endothelial apoptosis.