The Research Of Effect Of 17β-estadiol To The Abnormal P50 Auditory Evoked Potential Of Substantia Nigra Induced By Low-Dose MPTP In Female Rats

Objective To investigate Parkinson's disease model induced by low-dose enviroment toxin MPTP by means of unilateral sterotaxic injection to injury substantia nigra .To observe the effect and possible mechanism of 17β -estadiol to the abnormal P50 auditory evoked potential of substantia nigra induced by low-dose MPTP In Rats. Methods 139 health adult female Sprague-Dawley rats were randomly divied into nine groups: 1. normal control group(INT-N group); 2. MPTP Parkinson's disease model group(INT-MPTP group); 3.steril saline solution control group(INT-saline group); 4. ovariectomy contrl group(OVX-N group); 5. ovariectomy + MPTP Parkinson's disease model group(OVX-6-OHDA group); 6. ovariectomy + estrogen replacement group(OVX-E2-N group); 7. ovariectomy + estrogen replacement + MPTP Parkinson's disease model group(OVX-E2- MPTP group); 8. ovariectomy + olive oil solution control group(OVX-OIL-N group); 9. sham control group(Sham-N group). P50 auditory evoked potentials of substantia nigra were recorded in experimental situations .Our study want to know whether estrogen can restore the abnormal P50 auditory evoked potential of substantia nigra induced by low-dose MPTP In Rats. Results (1) following behavioral testing : Three groups(low-dose MPTP Parkinson's disease model group, ovariectomy + low-dose MPTP Parkinson's disease model group, ovariectomy + estrogen replacement + low-dose MPTP Parkinson's disease model group) were identified to be successful Parkinson's disease models by mens of apomorphine-induced ratations; (2) The T/C ratio of P50 is decreased significantly in low-dose MPTP Parkinson's disease model group as compared to normal control group(P<0.01); (3) The T/C ratio of P50 is decreased significantly in ovariectomy contrl group as compared to normal control group(P<0.01); (4) The T/C ratio of P50 is decreased significantly in ovariectomy + low-dose MPTP Parkinson's disease model group as compared to low-dose MPTP3Parkinson's disease model group(P<0.01); (5) The T/C ratio of P50 is increased in ovariectomy + estrogen replacement + low-dose MPTP Parkinson's disease model group as compared to ovariectomy + low-dose MPTP Parkinson's disease model group(P<0.01). Conclusion Directly injection low-dose MPTP into unilateral substantia nigra can result in abnormal P50 auditory evoked potential of substantia nigra in normal, ovariectomy and ovariectomy + estrogen replacement female rats; Gonadic estrogen replacement can oppose the abnormal P50 auditory evoked potential of substantia nigra ; Gonadic estrogen is the most important resource of estrogen deriving from brain; P50 auditory evoked potential, as a useful mothod, can be used for advanced research of Parkinson's disease model in rats;...