Effect Of Rhubarb On Function And Structure Of Hypothalamus And Pituitary In Female Rats And Its Reversibility

Objectives To observe the effects of rhubarb on function and structure of hypothalamus,pituitary in female rats and its reversibility,to probe the mechanism of rhubarb on the female reproductive toxicity,whether RTA is the main toxicity part of rhubarb,to provide the experimental basis for clinical safe medication.Methods Ninety SD female rats were randomly divided into normal control group,the 2g kg^-1 of RWD group and the 73 mg kg^-1 of RTA group,and each group contains 30 rats.All rats were administered intragastrically the corresponding drugs and lasted for 60 days,and the time of anestrus stage was recorded,meanwhile,the rate of estrous cycle disorder was calculated.Respectively,each group needed one third of rats to draw blood from abdominal aorta,to take the hypothalamus and pituitary which are weighed,and calculated pituitary index after 24 hour,30 days and 60 days of stopping given medicine.The morphological changes of the hypothalamus and pituitary were observed by HE staining.ELISA was used to detect level of the Gn RH,LH and FSH in serum.Results 1 Comparison of disordered rate of estrous cycle 1)RWD and RTA: The rate of administration 60 days group was higher than that of NC group（P<0.01）.There was no significant differences between the withdrawal 30 days group and that of administration 60 days group（P>0.05）.The withdrawal 60 days group was lower than that of administration 60 days group and withdrawal 30 days（P<0.05 or P<0.01）,compared with that of NC group,no statistical significance difference was found（P>0.05）.2)Comparison between RWD and RTA: In administration 60 days,the rate of RWD group was lower than that of RTA group（P<0.05）.In withdrawal 30 and 60 days,there was no significant differences between the RWD group and that of RTA group（P>0.05）.2 Comparison of the time of diestrum 1)RWD and RTA: The time of administration 60 days group was longer than that of NC group（P<0.05 or P<0.01）.The withdrawal 30 days group was shorter than that of administration 60 days group（P<0.05 or P<0.01）,compared with that of NC group there was no statistical significance difference（P>0.05）.The withdrawal 60 days group was shorter than that of administration 60 days group（P<0.01）,and compared with that of withdrawal 30 days and NC group,no statistically significant difference was found（P>0.05）.2)Comparison between RWD and RTA: In administration 60 days,the time of RWD group was shorter than that of RTA group（P<0.01）.In withdrawal 30 and 60 days,there was no significant differences between the RWD group and that of RTA group（P>0.05）.3 Comparison of the influence of the indexes of pituitary 1)RWD and RTA: The index of administration 60 days group was higher than that of NC group（P<0.05 or P <0.01）.In RWD,there was no significant differences between the withdrawal 30 days group and that of administration 60 days,NC group（P>0.05）.In RTA,the withdrawal 30 days group was lower than that of administration 60 days group（P<0.01）.The withdrawal 60 days group was lower than that of administration 60 days group（P<0.05 or P<0.01）,compared with that of withdrawal 30 days group and NC group,no statistical significance difference was found（P>0.05）.2)Comparison between RWD and RTA: In administration 60 days,the index of RWD group was lower than that of RTA group（P<0.05）.In withdrawal 30,60 days,there was no significant differences between the RWD group and that of RTA group（P>0.05）.4 The effects on the morphological changes of hypothalamus: In the NC group,number of the hypothalamus cell is moderate.In RWD and RTA administration group for 60 days,the hypothalamus neurons were reduced.There weresome phenomena appeared,including red neurons,ghost cell and chromatin marginal,moreover,in RTA group the phenomenon were worse.In RWD and RTA withdrawal group for 30 days,the number of hypothalamus neurons increased,but the red neurons,ghost cell and chromatin marginal were reduced.In RWD and RTA withdrawal group for 60 days,these pathological changes mentioned were further recovered.5 The effects on the morphological changes of pituitary: In the NC group,the pituitary cells were arranged in neat rows.In RWD and RTA administration group for 60 days,the quantity of pituitary cell decreased.At the same time,cells were not arranged in neat rows.Blood sinus expansion was serious and adaptability of eosinophilic cell hyperplasia,and in RTA group the phenomenon were worse.In RWD and RTA withdrawal group for 30 days,the quantity of pituitary cell increased,and then blood sinus expansion and adaptability of eosinophilic cell hyperplasia reduced.In RWD and RTA withdrawal group for 60 days,these pathological changes mentioned were further recovered.6 Comparison of the influence on hormone level in serum 1)RWD and RTA: In the administration 60 days group,the levels of LH and FSH were higher than those of NC group,but the level of Gn RH was lower than that of NC group（P<0.01）.In the withdrawal 30 days group,the levels of LH,FSH were higher than those of NC group,but the level of Gn RH was lower than that of NC group（P<0.05 or P<0.01）;compared to levels of the administration 60 days group,no statistical significance difference was found（P>0.05）.In the withdrawal 60 days group,the levels of LH and FSH were lower than those of the administration 60 days group,however,the level of Gn RH was higher（P<0.05 or P<0.01）;compared to the level of the FSH and Gn RH of withdrawal 30 days group,no statistical significance difference was found（P>0.05）,in RWD the level of LH was lower（P<0.05）,in RTA the level of LH no significant differences between the withdrawal group for 30 days and 60 days was found（P>0.05）;compared to levels of the NC group,no statistical significance difference was found（P>0.05）.2)Comparison between RWD and RTA: In administration 60 days and withdrawal 30 days,60 days,there were no significant differences in levels of LH,FSH and GnRH between the RWD group and the RTA group（P>0.05）.Conclusions 1 Rhubarb have an obvious effect on reproductive function of female rats for a long-term application.2 It showed that the damage of hypothalamus and pituitary that is related to influence of rhubarb on reproductive function of female rats.3 RAT was the main effective parts of rhubarb for reproductive toxicity.4 Rhubarb caused the reversible damage of reproductive function,all indexes were normal almost after withdrawal 60 days.