OBJECTIVETo study whether previously intravenous injection of anisodamine can prevent endotoxemia of heat stroke of rats.

METHODSExperimental animals were randomly divided into two groups, their average artery pressure, heart rate, survival time, survival rate and rectal temperature were measured at an environmental temperature of 38 degrees C-40 degrees C and 50%-60% retative humidity. Blood samples for endotoxins analyses were taken both before and after heat-stress.

RESULTSDuring heat stress, the animals of rectal temperature of the experimental and control groups continuously increased and two hours later, separately to (42.7 +/- 0.6) degree C and (43.1 +/- 0.5) degree C, without statistic difference(P > 0.05), and to (44.6 +/- 0.4) degree C and (44.2 +/- 0.3) degree C prior to death, with statistic difference(P < 0.05). Before the experiment, the contents of endotoxins of portal vein blood were (45.7 +/- 5.2) pg/ml and (42.6 +/- 5.4) pg/ml, and that of systemic blood was (14.8 +/- 4.5) pg/ml and (13.9 +/- 7.2) pg/ml, without statistic difference(P > 0.05). Two hours later, the contents of portal vein blood separately increased to (122.2 +/- 16.7) pg/ml and (49.7 +/- 10.2) pg/ml, obviously higher than that before heat-stress(P < 0.01). And there were clear statistic difference between the two groups(P < 0.01). The changing tendency of the heart rhythm is almost the same in two groups, that is, first rose and then fell. But it is without statistic difference before and two hours later(P > 0.05): before heat-stress, the average artery pressures were (13.3 +/- 0.6) kPa and (13.6 +/- 0.5) kPa, without statistic difference(P > 0.05), and two hours later, were (9.6 +/- 0.5) kPa and (8.6 +/- 0.6) kPa, with obvious statistic difference(P < 0.01). The survival time of the animals were (166.5 +/- 16.9) min and (144.5 +/- 18.2) min with obvious statistic difference(P < 0.01), the survival rate of heat stressed rats in the experimental group were obviously higher than control group(P < 0.01 or P < 0.05).

CONCLUSIONSAnisodamine can prevent endotoxemia in rats suffering heat stroke.