Experimental Study On The Inhibition On The HPG Axis Of Pubertal Rats By Arnebia

Background: Precocious puberty (PP) causes the children's final adult height shorter than normal ones, gives heavy psychiatric burden to both the PP children and their parents. Till today, treatments for PP are very limited. Gonadal releasing hormone analogue (GnRHa) can prohibit the process of central precocious puberty (CPP), but it is too expensive to use widespread, and few effective methods to peripheral precocious puberty (PPP).Therefore, looking for an effective, cheap and safe drug is very necessary. The Chinese medicine Arnebiae has anti-reproduction effect, maybe it can treat PP by prohibiting the activation of hypothylamtus-pituitary-gonad axis (HPGA). We selected pubertal rats, investigated the effect of arnebiae on HPGA and the length of function time, and discussed the mechanism .Objects and Methods: 80 SD mature female rats were randomly divided into normal saline (NS) group, i.e."negative control"(irrigated with NS 2ml/d ), GnRHa group, i.e."positive control"(Diphereline 1mg/kg I.H. once in three weeks, twice)and arnebiae group (arnebiae 15 g/kg·d ), which I.P. of HMG (37.5u/kg·d qd×10d) were also carried on since the 22nd day of irrigation. On 21st, 42nd day of irrigation and 21st day after withdrawal, the animals were executed respectively, serum levels of FSH,LH,E2 were tested, and the vaginal cytology were observed. In the arnebiae group, HMG was carried on the 42nd day, and continued 10 days, variations of the hormone level and cytology are also assessed.Results:1. Variation of the serum FSH, LH, E2After 21 days, the concentration of the serum, FSH, LH, E2 in arnebiae group is 1.66±0.130miu/ml,0.31±0.119 miu/ml和20.89±6.370 pg/ml, and that of negative control is 2.59±0.547 miu/ml,1.24±0.975 miu/ml,37.11±19.762 pg/ml,and which of positive control group is 1.33±0.162 miu/ml,0.44±0.175 miu/ml,13.84±3.423 pg/ml,respectively, We can see that the levels of the serum FSH, LH, E2 in arnebiae group are much lower than the negative control(P<0.01), but familiar with the positive control.2. Vaginal cytology After irrigation, basal cells are much more than superficial ones in the arnebiae group and the positive control, the vagina is much drier, vaginal degree of relaxation reduces. While in the negative control on the contrary, superficial cells are much more than basal ones, the vagina is very wet and smooth, and vaginal degree of relaxation varies little, which correspond to the variation of hormone.3. Variation of HPGA after adding HMG to Arnebiaee group HMG was added in the Arnebiaee group, before that, the serum level of FSH, LH, E2 is 1.66±0.130 miu/ml,0.31±0.119 miu/ml,20.89±6.370 pg/ml, while after that, it becomes 4.10±0.458 miu/ml,10.53±2.746 miu/ml,18.95±3.111 pg/ml, respectively. LH,FSH levels increases dramatically, but the E2 concentration does not vary much .4. Changes of hormone and vaginal cytology with the retreatment of all drugs. After withdrawal with all drugs, the concentration of serum LH,FSH and E2 is 2.96±0.303 miu/ml,1.53±0.432 miu/ml,62.82±15.625 pg/ml in negative control, 3.59±0.726 miu/ml,1.38±0.271 miu/ml,64.80±20.569 pg/ml in arnebiae group, 3.28±0.414 miu/ml,1.19±0.182 miu/ml,64.25±11.868 pg/ml in positive control, respectively. the difference between the three groups vanishes. The major vaginal cells are superficial ones.Conclusions:1. Chinese Arnebiae can inhibit HPGA of pubertal rats.2. Arnebiae may inhibits both hypothylamus and peripheral gonads.3. The control disappears after withdrawal indicates that Arnebiae's effect is reversible.