Hemodynamic responses to glycols and to hemolysis

Ethylene and propylene glycol both decrease renal blood flow in dogs while increasing flow through the superior mesenteric artery. The decrease in renal blood flow is not a passive response to dilatation of major vascular beds since it precedes the increment in superior mesenteric arterial flow and since it can be duplicated by direct injection of glycols into the renal artery. These rheological changes in response to glycols are at least partly due to hemolysis since intravenous injection of plasma from hemolyzed blood or of crystalline hemoglobin produces the same pattern of response, which is not blocked by phenoxybenzamine. However, the production of hemoglobinemia may not be the sole explanation for the vascular responses to the glycols, since a concentration of 2 %, which does not induce detectable hemolysis, still produces the characteristic increase in superior mesenteric artery blood flow.