An immunohistochemical study on α-ketoglutarate dehydrogenase complex in Parkinson's disease

✍ Scribed by Dr. Yoshikuni Mizuno; Sadayuki Matuda; Hiroyo Yoshino; Hideo Mori; Nobutaka Hattori; Shin-Ichirou Ikebe

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 730 KB
• Volume: 35
• Category: Article
• ISSN: 0364-5134
• DOI: 10.1002/ana.410350212

✦ Synopsis

We report an immunohistochemical study of the mitochondrial a-ketoglutdrdte dehydrogenase complex (KGDHC) in the substantia nigra in Parkinson's disease. The KGDHC, the three enzyme complex catalyzing the oxidation of a-ketoglutarate to succinate through succinic semialdehyde, is the rate-regulating enzyme of the TCA cycle. The mitochondrial toxin, MPP+. inhibits not only complex 1 but also the KGDHC. Therefore, we investigated this enzyme complex in Parkinson's disease. In the control patients (n = 6), the imrnunostaining of the melanized nigral neurons was generally uniform; most of the melanized neurons showed good immunostaining with some neurons showing somewhat reduced staining. In Parkinson's disease (n = 9), many melanized neurons showed reduced immunostaining for the KGDHC, and those neurons were more frequently seen in the lateral one-third of substantia nigra. The decrease in the immunostaining for the KGDHC correlated roughly with the severity of degeneration. The KGDHC is more Vulflerdhle to degeneration than complex 11, 111, and IV as noted in our previous inimunohistochemical study. Even if secondary, the loss may play a role in the progression of the disease.