Gaginella T S, Stewart J J, Olsen W A, Bass P
J Pharmacol Exp Ther. 1975 Nov;195(2):355-61.
Ricinoleic acid, the active component of castor oil, and related fatty acids were studied to determine their relative inhibitory effects on water and electrolyte absorption using everted hamster jejunal and ileal segments. Differences were found between hydroxylated and nonhydroxylated congeners as well as between cis and trans geometric isomers. At a mucosal concentration of 2.0 mM, the unsaturated fatty acids had the following rank order of potency on inhibition of water absorption: ricionoleate greater than or equal to ricinelaidate- greater than equal to linoleate greater than oleate greater than linelaidate greater than elaidate. Ricinoleyl alcohol was effective at 2.0 mM but the methyl ester of ricinoleic acid was ineffective at this concentration. Among a series of saturated fatty acids including palmitate, stearate, a mixture of 9- and 10-hydroxystearate, and 12-hydroxystearate, only the last compound had any inhibitory effect on water absorption. The results define those portions of the ricinoleic acid molecule required for its effect on water and electrolyte absorption and suggest that classification of this cathartic as an "irritant" or "stimulant" should be re-evlauated.
研究了蓖麻油的活性成分蓖麻油酸及相关脂肪酸，利用外翻的仓鼠空肠和回肠段来测定它们对水和电解质吸收的相对抑制作用。发现羟基化和非羟基化同系物之间以及顺式和反式几何异构体之间存在差异。在黏膜浓度为2.0 mM时，不饱和脂肪酸对水吸收抑制作用的效力顺序如下：蓖麻油酸酯大于或等于反蓖麻酸酯大于或等于亚油酸酯大于油酸酯大于反油酸酯大于反亚油酸酯。蓖麻油醇在2.0 mM时有效，但蓖麻油酸甲酯在此浓度下无效。在一系列饱和脂肪酸中，包括棕榈酸酯、硬脂酸酯、9-羟基硬脂酸酯和10-羟基硬脂酸酯的混合物以及12-羟基硬脂酸酯，只有最后一种化合物对水吸收有任何抑制作用。这些结果确定了蓖麻油酸分子中对其水和电解质吸收作用所必需的部分，并表明这种泻药归类为“刺激性”或“刺激性”应重新评估。
