Vascular Reactions of the Islets of Langerhans in Escherichia Coli Endotoxemia in Mice

Abstract

An experimental study of Escherichia coli endotox-emia was made in mice to correlate the microvascular reactions of the islets of Langerhans with levels of blood glucose. Following intravenous injection of endotoxln in an LD50 or more, intravascular clumping of blood cells was observed. Constriction of insular arterloles and venules, with alternating rapid and slow flow, was predominant at first but was succeeded by persistent dilation and slow flow. The vasomotor changes were especially prominent in the venules. The microvascular reactions were accelerated and more severe in mice receiving the lethal dose. In addition, the blood flow in the islets stopped intermittently for protracted periods in the terminal stages after a lethal dose. The fluctuations in blood glucose suggest that abnormal insular function may accompany the abnormal vascular reactions in endotoxemia, since the phase of constriction is accompanied by a hyperglycemic peak, whereas the phase of dilation is accompanied by hypoglycemla. The implications of these findings in human bacteremic shock due to Gram-negative enteric bacilli, a syndrome which has assumed increasing importance in recent years, are discussed.