CORRELATION BETWEEN THE PLASMA HISTAMINE AND CATE- CHOLAMINE CONCENTRATIONS AND THE CHANGES OF HEMO- DYNAMICS AND MICROCIRCULATION DURING ENDOTOXIN SHOCK IN DOGS / 第二军医大学学报

ABSTRACT

The plasma histamine concentration was elevated from the control level of 1.16? 0.28ng/ml to 11.42?5.2ng/ml 2-5 min after intravenous injection of Serratia mar-cescens endotoxin,and then declined gradually.The level was still slightly higher than the control 4 h later. The plasma noradrenaline(NA)and adrenaline (Ad) concentrations were increased from the control value of 1.13?0.28ng/ml and 1.05 ?0.32ng/ml to 7.33?1.86ng/ml and 10.04? 3.94ng/ml respectively. Six h later they were still significantly elevated.Arterial blood pressure was reduced to 24.16%of the control level 2-5 min after injection and to 69.2% 6 h later.Both cardiac output and cardiac index were decreased, but the peripheral resistance was increased during endotoxin shock. The significant dilatation of arterioles, venules and capillaries of bulbar conjunctiva microcirculation occurred 1-2 min after endotoxin injection, and the blood flow slowed down at the same time.Five min - six h after endotoxin injection arterioles constricted markedly, but capillaries and venules were still congested and distended.From this study, the interrelationship of some changes in the development of endotoxin shock were discussed.Endotoxin caused the congestion in microcirculatiolelen, reduction of blood returning to the heart and reduced peripheral resistance owing to the histamine released in large amounts. Drastic drop in blood pressure resulted in the increase of NA and Ad release reflexly, which led to the constriction of arterioles, the increase of the peripheral resistance and the restoration of the blood pressure to some extent.Since venules and capillaries were distended and congested,blood pressure and cardiac output still remained at lower level all the time during endotoxin shock.