Svoboda J A, Thompson M J, Robbins W E, Elden T C
Lipids. 1975 Sep;10(9):524-7. doi: 10.1007/BF02532353.
Radiolabeled sterols, 14C-cholesterol, 14C-cholestanol, 3H-stigmasterol, 3H-stigmastanol, and 3H-sitosterol, were fed to larvae of the Mexican bean beetle, Epilachna varivestis Mulsant, bu coating soybean leaves. Free sterol and sterol ester fractions from treated insects were isolated and analyzed, and in each case nearly 30% or more of total radiolabeled sterols retained by the insect were found in the sterol ester fraction after 8 days. delta5-Dietary sterols were readily reduced to stanols, and C29-stanols thus produced were dealkylated to cholestanol. Significant amounts of labeled lathosterol were formed from delta5-C29 sterols; little, if any, radiolabeled cholesterol was detected in insects fed either of the labeled delta5-phytosterols, stigmasterol or sitosterol. Sterol metabolism of this insect thus differs considerably from that found for most phytophagous insects.
通过在大豆叶片上涂抹放射性标记的甾醇、14C-胆固醇、14C-胆甾烷醇、3H-豆甾醇、3H-豆甾烷醇和3H-谷甾醇，将其投喂给墨西哥豆瓢虫（Epilachna varivestis Mulsant）的幼虫。从处理过的昆虫中分离并分析游离甾醇和甾醇酯部分，在每种情况下，8天后在昆虫体内保留的总放射性标记甾醇中，近30%或更多存在于甾醇酯部分。膳食中的Δ5-甾醇很容易还原为甾烷醇，由此产生的C29-甾烷醇会脱烷基生成胆甾烷醇。从Δ5-C29甾醇中形成了大量标记的羊毛甾醇；在投喂标记的Δ5-植物甾醇（豆甾醇或谷甾醇）的昆虫中，几乎检测不到放射性标记的胆固醇。因此，这种昆虫的甾醇代谢与大多数植食性昆虫的甾醇代谢有很大不同。
