The effect of endotoxin on microcirculatory and lymphatic dynamics in the rat (Shwartzman phenomenon).

Observations and measurements of the responses of the rat's microcirculation and lymphatics during the Shwartzman reaction showed that (1) greater increases in arteriolar activity and more rapid derangement of capillary and postcapillary venular walls were induced by the Shwartzman phenomenon than by a single dose of endotoxin; (2) the hyperdynamic state persisted with the first dose of endotoxin but hypotensive low flow syndrome followed a delayed second administration of endotoxin; (3) the lymphatic contractile activity which was depressed with an initial dose also became hyper-reactive with the subsequent dose; (4) both the blood vessels and the lymphatics became hypersensitive to sympathomimetic amines. The pattern of events simulate the pattern seen during clinical endotoxin shock.