Wark J D, Taft J L, Michelangeli V P, Veroni M C, Larkins R G
Prostaglandins. 1984 Mar;27(3):453-63. doi: 10.1016/0090-6980(84)90203-x.
The effect of PGE2 on the conversion of 25-hydroxyvitamin D3 (25 OH D3) to 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) by isolated renal tubules from vitamin D deficient chicks was studied under a variety of experimental conditions. In the absence of added vitamin D metabolites, PGE2 (2 x 10(-6)M) caused an immediate inhibition of formation of 1,25-(OH)2D3, followed by a delayed stimulation, apparent after 15 h exposure to PGE2. Pretreatment of the tubules with 1,25-(OH)-2D3 prevented the immediate inhibitory action of PGE2, and allowed the stimulation to be apparent after 4 h exposure to PGE2. The cyclic nucleotide phosphodiesterase inhibitor 3-isobutyl-1-methyl xanthine (IBMX) significantly stimulated the formation of 1,25-(OH)-2D3. PGE2 significantly inhibited 1,25-(OH)2D3 formation in tubules which had been stimulated by IBMX. PGE2 stimulated the adenylate cyclase activity in a crude particulate fraction from the chick kidney, and raised cyclic adenosine 3', 5'-monophosphate (cyclic AMP) levels in the renal tubules. It is concluded that PGE2 can either stimulate or inhibit 1,25-(OH)2D3 formation in chick renal tubules. The stimulatory effect may be partly due to elevation of cyclic AMP. The mechanism of the inhibitory effect requires further investigation.
在多种实验条件下，研究了前列腺素E2（PGE2）对维生素D缺乏雏鸡分离的肾小管将25-羟基维生素D3（25 OH D3）转化为1,25-二羟基维生素D3（1,25-(OH)2D3）的影响。在不添加维生素D代谢物的情况下，PGE2（2×10⁻⁶M）立即抑制1,25-(OH)2D3的形成，随后出现延迟刺激，在暴露于PGE2 15小时后明显。用1,25-(OH)-2D3预处理肾小管可防止PGE2的立即抑制作用，并使在暴露于PGE2 4小时后刺激明显。环核苷酸磷酸二酯酶抑制剂3-异丁基-1-甲基黄嘌呤（IBMX）显著刺激1,25-(OH)-2D3的形成。PGE2显著抑制由IBMX刺激的肾小管中1,25-(OH)2D3的形成。PGE2刺激雏鸡肾脏粗颗粒部分中的腺苷酸环化酶活性，并提高肾小管中环磷酸腺苷（环AMP）水平。得出结论，PGE2可以刺激或抑制雏鸡肾小管中1,25-(OH)2D3的形成。刺激作用可能部分归因于环AMP的升高。抑制作用的机制需要进一步研究。
