Does vasospasm occur in small pial arteries and arterioles of rabbits?

Abstract

Background: Vasospasm is a serious complication associated with subarachnoid hemorrhage. Successful management of vasospasm will ultimately depend on a clear understanding of the scope of this phenomenon, including whether arterial elements of different calibers are equally affected. We therefore examined the responses to subarachnoid hemorrhage in rabbit basilar arteries, small pial arteries, and arterioles.Summary of Report: We compared the brain stem pial arteries of 10 perfusion-fixed male New Zealand White rabbits after experimental subarachnoid hemorrhage to those of five control rabbits using morphological analysis of cross-sections of plastic-embedded vessels. After subarachnoid hemorrhage, the internal elastic lamina was highly corrugated in all basilar arteries (mean diameter 319±51 /im). These arteries were severely constricted in comparison with the control group, in which the mean diameter was 691 ±17 /im, and corrugation of the internal elastic lamina was not present. In contrast, small pial arteries and arterioles very rarely demonstrated a vasoconstrictive configuration after subarachnoid hemorrhage. The contractility of the smaller vessels was confirmed by injecting 2 mg/kg BaCI 2 intracisternally. Following BaCl 2 injection, corrugation of the internal elastic lamina was detected in the small arteries and arterioles as well as the basilar arteries.Conclusions: We conclude that experimental chronic vasospasm after subarachnoid hemorrhage in rabbits tends to occur in large conducting arteries rather than in smaller pial arteries and arterioles. (Stroke 1991;22:1419-1425)

Acute Cerebral Artery Constriction in the Spontaneously Hypertensive Rat following Blood and Plasma Administration into the Subarachnoid Space

“…Morphometric and direct visual analyses of the piai and intraparenchymal vessels of the brain have indicated subsequently that blood or bar ium chloride can induce vasospasm in vessels below the threshold of angiographic detection [19,21,41], The results of the present study provide additional evidence in favor of small-vessel vasospasm following SAH. It is important to recognize, however, that Asano and Sano [1] could not exclude the possibility that SAH-induced in creases in intracranial pressure were responsible for the observed filling defects.…”

Responses of rat basilar artery to acetylcholine and platelet products in vivo.

“…The findings that both thromboxane and serotonin produce potent constriction and that ADP produces little dilatation suggest that the net effect of platelets would be constriction of the basilar artery. It is interesting to note that Nihei et al 32 recently suggested that vasospasm following subarachnoid hemorrhage tends to occur in large arteries.…”

Dynamic Alterations of Cerebral Pial Microcirculation During Experimental Subarachnoid Hemorrhage

“…A good understanding of cerebral microcirculation and the pathogenesis of cerebral injury after SAH facilitates the development of new preventive and therapeutic approaches to SAH. Although an acute increase in microvascular permeability (Germano et al 2000) and platelet aggregation in the cerebral microvasculature (Sehba et al 2005) have been noted, the alterations of cerebral microcirculation following SAH are poorly defined and remain debatable (Nihei et al 1991;Uhl et al 2003;Park et al 2001). The present study was undertaken to investigate the changes of cerebral pial microcirculation following SAH using a novel rat model.…”