Blomhoff R, Helgerud P, Dueland S, Berg T, Pedersen J I, Norum K R, Drevon C A
Biochim Biophys Acta. 1984 May 16;772(2):109-16. doi: 10.1016/0005-2736(84)90033-6.
The lymphatic absorption and transport of retinol and vitamin D-3 from rat intestine has been studied. When rats were cannulated in the intestinal lymph duct and given an intraduodenal bolus of [3H]retinol and 14C-labelled vitamin D-3, 14C-labeled vitamin D-3 appeared later in the intestinal lymph than [3H]retinol and the rate of absorption of vitamin D-3 was still maximal at a time when that of retinol had declined. Both vitamins were absorbed via the lymphatic route in association with chylomicrons. Almost all the retinol was esterified, while vitamin D-3 appeared in the chylomicrons as free vitamin D-3. In vitro incubations and in vivo studies using hepatectomized and normal rats showed that the retinyl ester was a relatively nonexchangeable component of the chylomicrons and their remnants. Hence, all the vitamin A followed the remnants in their clearance from plasma. In contrast, significant amounts of vitamin D-3 were transferred from the chylomicrons to other plasma fractions. Therefore, only a fraction of this vitamin may be removed in association with the chylomicron remnants.
已对大鼠肠道中视黄醇和维生素D - 3的淋巴吸收及转运进行了研究。当给大鼠的肠淋巴管插管，并经十二指肠给予[3H]视黄醇和14C标记的维生素D - 3推注时，14C标记的维生素D - 3在肠淋巴中出现的时间比[3H]视黄醇晚，且在视黄醇吸收速率已经下降时，维生素D - 3的吸收速率仍处于最大值。两种维生素均通过淋巴途径与乳糜微粒一起被吸收。几乎所有的视黄醇都被酯化，而维生素D - 3以游离维生素D - 3的形式出现在乳糜微粒中。使用肝切除大鼠和正常大鼠进行的体外孵育及体内研究表明，视黄醇酯是乳糜微粒及其残粒中相对不可交换的成分。因此，所有维生素A都随着残粒从血浆中清除。相比之下，大量维生素D - 3从乳糜微粒转移到其他血浆组分中。因此，这种维生素只有一部分可能会与乳糜微粒残粒一起被清除。
