Development of a vitamin D-responsive organ culture system for adult and old rat intestine.
Development of a vitamin D-responsive organ culture system for adult and old rat intestine.
复制标题
开发成年和老年大鼠肠道维生素 D 响应器官培养系统。
DOI：
10.1023/a:1021038129203
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发表时间：
2002
影响因子：
3.1
通讯作者：
Kumar,VB
中科院分区：
文献类型：
--
作者：
Armbrecht,HJ;Boltz,MA;Kumar,VB
本研究的目的是建立一种对维生素D有反应的成年和老年大鼠小肠器官培养系统。将来自F344大鼠的外植体在置于6孔培养皿中的Millipore组织培养插入物上在28°C的温度和95%氧气的存在下培养。通过DNA和蛋白质合成的恒定速率确定，年轻（2个月大）、成年（12个月大）和老年（22个月大）大鼠的外植体可存活长达12小时。通过测量1，25-二羟基维生素D [1，25（OH）2D]（维生素D的激素形式）增加肠道24-羟化酶细胞色素P-450（CYP 24）mRNA水平的能力来表征激素反应性。幼年大鼠的空肠外植体对1，25（OH）2D的反应以线性方式增加CYP 24 mRNA水平，EC 50为3 nM。在时间（0-12小时）或剂量（0.1-100 nM）方面，空肠反应的幅度不随年龄变化。然而，在十二指肠，1，25（OH）2D增加CYP 24 mRNA在成人显着更高的水平相比，年轻。由于24-羟化酶是1，25（OH）2D在肠道中降解途径的第一步，因此十二指肠24-羟化酶表达的增加可能导致1，25（OH）2D对成年十二指肠的作用降低。
The purpose of this study was to develop an organ culture system for adult and old rat small intestine that is responsive to vitamin D. Explants from F344 rats were cultured on Millipore tissue culture inserts placed in 6-well dishes at a temperature of 28°C and in the presence of 95% oxygen. Explants from young (2 months old), adult (12 months old), and old (22 months old) rats were viable for up to 12 hr as determined by constant rates of DNA and protein synthesis. Hormonal responsiveness was characterized by measuring the capacity of 1,25-dihydroxyvitamin D [1,25(OH)2D], the hormonal form of vitamin D, to increase mRNA levels of the intestinal 24-hydroxylase cytochrome P-450 (CYP24). Jejunal explants from young rats increased CYP24 mRNA levels in a linear fashion with an EC50of 3 nM in response to 1,25(OH)2D. There was no change with age in the magnitude of the jejunal response with regard to time (0–12 hr) or dose (0.1–100 nM). However, in the duodenum, 1,25(OH)2D increased CYP24 mRNA to significantly higher levels in the adult compared to the young. Since the 24-hydroxylase is the first step in the degradative pathway for 1,25(OH)2D in the intestine, increased duodenal expression of the 24-hydroxylase may contribute to the decreased action of 1,25(OH)2D on the adult duodenum.