The Nitric Oxide Synthase Activity in Corpora Allata of the Cockroach, Diploptera punctata.

• Main Authors: Wen Chih-jen, 溫志仁
• Other Authors: Ann-Shyn Chiang
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/71272655302626028381

碩士 === 國立清華大學 === 生命科學系 === 87 === It is now well established that nitric oxide (NO) is a neurotransmitter of the mammals and insects. For endocrine system, however, it is known that NO plays an important role in the functional modulation of endocrine glands in mammals, but there is not any literature about NO in insect endocrine system until now. After finding that corpus allatum (CA) cells of Diploptera punctata, Periplaneta americana, Blattella germanica and Leucania loreyi contains nitric oxide synthase (NOS), we now demonstrate NOS activity in CA furthermore. NADPH-diaphorase staining is a major method to study NOS activity. In previous NADPH-diaphorase staining, nitro blue tetrazolium chloride (NBT) is used as tetrazolium salt. Here, we shown that CA exhibit a cycle of NADPH-diaphorase activity during reproductive cycle in the D. punctata adult females. But the formazan product from NBT precipitate is difficult for quantification by standard spectrophotometric techniques. We use the new tetrazolium salt 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) to replace NBT in NADPH-diaphorase staining. The extremely water-soluble formazan product of XTT does not require solubilization prior to quantification. We develop this new assay with XTT, demonstrate its efficacy, and acquire NOS activity in CA of the cockroach, Diploptera punctata.