Spontaneously hypertensive rat mesenteric microvsascular networks undergo angiogenesis in response to a wound healing stimulus

Abstract

Hypertension is associated with increased microvascular resistance due in part to a loss of microvessels, termed microvascular rarefaction. Understanding whether this loss of microvessels is a result of vessel regression or impaired growth requires further investigation of the ability of hypertensive networks to undergo angiogenesis. The objective of this study was to determine the angiogenic response of mesenteric microvascular networks in adult spontaneously hypertensive versus normotensive rats. Mesenteric tissues were harvested from 15‐16 week old spontaneously hypertensive and Wistar rats according to 3 experimental groups: unstimulated, 3 days post and 5 days post wound healing stimulus induced by 20 min exteriorization of the mesentery. Microvascular networks were immunohistochemically identified by PECAM labeling. Consistent with the phenomenon of rarefaction, SHR unstimulated microvascular networks were smaller than normotensive controls. By 3 days post stimulation both SHR and Wistar microvascular networks displayed increased capillary sprouting. By 5 days both SHR and Wistar microvascular networks displayed an increase in vascular area. These observations suggest that hypertensive microvascular networks are able to undergo angiogenesis similar to normotensive networks.