Komuniecki P R, Vanover L
Mol Biochem Parasitol. 1987 Jan 15;22(2-3):241-8. doi: 10.1016/0166-6851(87)90055-7.
Ascaris suum L3 larvae isolated from rabbit lungs undergo the third ecdysis to L4 larvae after 3 days in culture under a gas phase of 85% N2/10% CO2/5% O2. The L3 larvae contain substantial malic enzyme activity and are capable of producing small amounts of the reduced organic acids characteristic of the fermentative pathways which operate in the adult. However, only a small portion of the total carbon utilized is accounted for by these reduced acids and their motility is cyanide-sensitive, suggesting that their energy-generating pathways are predominantly aerobic. In contrast, after ecdysis, the L4 larvae begin to utilize glucose at a greater rate and the proportion of total carbon utilized which is accounted for as propionate, 2-methylbutyrate and 2-methylvalerate also increases. In addition, motility becomes increasingly cyanide-insensitive, suggesting that these L4 larvae are able to utilize the anaerobic energy-generating pathways of the adult. Surprisingly, on day 10 in culture, these L4 larvae, although capable of producing reduced volatile acids, still retain substantial cyanide-sensitive cytochrome oxidase activity.
从兔肺中分离出的猪蛔虫L3幼虫，在85% N2/10% CO2/5% O2气相条件下培养3天后，经历第三次蜕皮成为L4幼虫。L3幼虫含有大量苹果酸酶活性，能够产生少量成体中运作的发酵途径特有的还原有机酸。然而，这些还原酸仅占总碳利用量的一小部分，并且它们的运动对氰化物敏感，这表明它们的能量产生途径主要是有氧的。相比之下，蜕皮后，L4幼虫开始以更快的速度利用葡萄糖，作为丙酸盐、2-甲基丁酸酯和2-甲基戊酸酯的总碳利用比例也增加。此外，运动对氰化物的敏感性越来越低，这表明这些L4幼虫能够利用成体的厌氧能量产生途径。令人惊讶的是，在培养第10天，这些L4幼虫虽然能够产生还原挥发性酸，但仍保留大量对氰化物敏感的细胞色素氧化酶活性。
