Tcholakian R K, Berkowitz A S, Newaz S N
J Steroid Biochem. 1985 Feb;22(2):263-5. doi: 10.1016/0022-4731(85)90122-0.
The metabolism of [3H]oestradiol by interstitial cells in culture prepared from 18-day old rat testes was investigated. Interstitial cells were able to convert [3H]oestradiol to [3H]oestriol as confirmed by recrystallization of oestriol to constant specific activity from samples containing cells and not from controls. This demonstrated for the first time the presence of 16 alpha-hydroxylase in rat testicular interstitial cells. The effect of in vitro FSH treatment on the cells in culture was also investigated. FSH failed to affect 16 alpha-hydroxylase activity since we could not demonstrate a significant difference between treated and untreated preparations. The 16 alpha-hydroxylation of phenolic steroids is widely regarded as the major pathway of oestrogen metabolism in mammals. This metabolic step significantly reduces the biological activity of oestradiol. The presence of 16 alpha-hydroxylase in interstitial cells suggests that it may play a role in inactivating the oestradiol that is produced in the Leydig cells and thus prevent its intracellular accumulation. Such activity may conceivably play a role in the overall local "fine tuning" of androgen biosynthesis.
研究了从18日龄大鼠睾丸制备的培养间质细胞对[3H]雌二醇的代谢。通过从含细胞的样品而非对照样品中重结晶雌三醇至恒定比活性，证实间质细胞能够将[3H]雌二醇转化为[3H]雌三醇。这首次证明了大鼠睾丸间质细胞中存在16α-羟化酶。还研究了体外促卵泡激素（FSH）处理对培养细胞的影响。FSH未能影响16α-羟化酶活性，因为我们未能证明处理组和未处理组之间存在显著差异。酚类甾体的16α-羟化被广泛认为是哺乳动物雌激素代谢的主要途径。这一代谢步骤显著降低了雌二醇的生物活性。间质细胞中存在16α-羟化酶表明，它可能在使睾丸间质细胞产生的雌二醇失活中发挥作用，从而防止其在细胞内积累。可以想象，这种活性可能在雄激素生物合成的整体局部“微调”中发挥作用。
