Pressor Reactions and Bacterial Localization in Central Nervous System

Abstract

When we produce pressor episodes in an animal body, some region of the vascular bed must be relatively anoxemic. In such regions, particularly those in which vascular anastomoses are poor, or terminal vessels exist (skin, central nervous system, special sense organs, etc.) stimulation promptly follows, the endothelium of the capillaries becomes more permeable (Landis) 1 and we may assume that bacterial adhesion can here occur to a greater extent than under normal conditions of circulation.

In general, the capillaries of the brain and the central nervous system are less permeable than those of the splanchnic bed and consequently they are less “sticky”. Bacterial localization in the brain, considering the volume of the blood flow, is relatively infrequent—abscess formation certainly not common.

We were interested in the localization of bacteria in the central nervous system and for this purpose used single as well as repeated injections of pitressin (betahypophamine) to bring about periods of transient anoxemia in some of the tissues of the central nervous system. Increased stickiness and permeability of the endothelium of the blood vessels at the foci of anoxemic stimulation might enhance the localization of bacteria here as well as elsewhere.