Effect Of Yuxingcao Injection On Contents Of CAMP In Hypothalamus And AVP In Ventral Septal Area In Fever Rats

PrefaceThe Yuxingcao injection is a pure herb preparation which is distilled by Yuxingcao. Its effective component is Decanoyl aceta ldehyde. This drug has antipyretic and antitoxic effects. At present it is mainly used to antibosis,antiviral,antianaphylaxis and build up immunization of body. Whether this herb exerts its antipyretic effect through charging the level of neural mediators, and whether cAMP and AVP play a role in its antipyretic effect has not been reported up to present. In this study we used dry yeast to making fever model, through maturating the contents of cAMP in hypothalamus and AVP in VSA of rats and from two ways of positive and negative regulation we studied its antipyretic mechanism. This will introduce experimental gist for its clinical use and further development and usage.Materials and Methods1. animals and temperature surveyHealthy male Wistar rats were kept in our experimental environment 3 days before the experiment. The temperature was kept 22 ± 2℃. In our work we put the rats into special cages and the probe of the thermometer was put into the rectum for 6 cm. We took the mean value of three temperature before experiment as the basal temperature ( if the differences in temperature every two times were more than 0. 3℃ then the rat was knocked out).2. experiment group and disposalPart one: ( 1 ) control group;the normal saline was injected hypodermically (10ml ? kg" ). (2) model group*, after measuring the normal temperature the suspension of yeast (20%) was injected hypodermically (10ml ? kg ). Part two;the disposal of group one and two is the same as part one. (3) Yuxingcao lOg ? kg group;210 min after making model the celiac injection of Yuxingcao was administered (lOg ? kg~ ). (4) Yuxingcao 20g ? kg" group;the method is the same as Yuxingcao group 1 , the dosage is 20g ? kg " . The rats temperature of every group was noted every 60 min before 180 min and was noted every 15 min from 180 min after recording normal temperature until 360 min (this point is peak period of the fever induced by yeast ) , then the rats were decapitated quickly and hypothalamus tissues were taken out and put into liquid nitrogen for fixation, 20 min later the samples were transferred to refrigerator ( -70^ ) . At the same time, we put the remainder brain into boiling saline to cook for 5 min, then weighed 30 mg VSA tissues to dispose for measuring.3. disposal and assay of the sample of cAMP and AVPTake some hypothalamus and VSA tissues, then we began to assay the content of cAMP and AVP according to specification of the Test Kit .4. observation and statistical analysisobservation item ? ( 1 ) the mean temperature curve ( 360 min) . (2) differences in temperature at peak time ( 360 min after yeast injection ) . ( 3 ) thermal response index ( TRI) . (4 ) the content of cAMP in hypothalamus . (5) the content of AVP in VSA . Statistical analysis;all data were mean ± SD. The differences between groups were assessed by students test, and the correlation was evaluated by correlation analysis.Results1. the effects of yeast on rats and Yuxingcao injection on fevered rats caused by yeastThe temperature of control group did not change magnificently during the experiment. The model group rats'temperature began to raise after 180 min. and the peak time is at 360 min. the difference in temperature (AT) and 6h thermalresponse index (TRI6) were significantly higher than those in the control group (P <0. 01) . Compared with the model group AT at 150 min of Yuxingcao lOg ? kg"1 group and AT and TRI6 at 150 min of Yuxingcao 20g ? kg "'group had significant difference (P <0.01);compared between two herb groups, AT and TRI6 also had significant difference (P <0. 01, P <0. 05) . The data indicated that Yuxingcao injection could magnificently inhibit the yeast inducing fever, and the effect was correlated with dosage.2. the effects of Yuxingcao injectio on the contents of cAMP in hypothala-mus and AVP in VSA.Compared with control group the cAMP content in hypothalamus and AVP in VSA of model group were more higher ( P <0. 01) , the cAMP and AVP content of Yuxingcao lOg ? kg" group and model group had significant difference (P<0.05, P <0. 01) ,compared with model group the cAMP and AVP content of Yuxingxao 20g ? kg" group were more lower ( P <0. 01). Difference between these two herb groups also had statistical significance (P<0.01, P < 0. 05 ). Correlation analysis indicated that the content of cAMP in hypothalamus and AVP in VSA were positively correlative with AT (P <0. 01).Conclusion1. Yuxingcao has significant antipyretic effect on fevered rats induced by dry -yeast and this effect has dosage dependence.2. These suggest that Yuxingcao may partly possess antipyretic effect through inhibiting synthesis and/or facilitating decomposition of cAMP , and promoting the release of AVP in VSA. All these will decrease the content of cAMP in hypothalamus and AVP in VSA. Through these the drug exerts its antipyretic effect. And the change of cAMP and AVP contents are positively correlative with the difference in temperature.