兔肾外髓质细胞中前列腺素E-9酮还原酶活性增强。

Enriched prostaglandin E-9 ketoreductase activity in outer medullary cells of the rabbit kidney.

作者信息

Miller M J, Carroll M A, Schwartzman M, Ferreri N R, McGiff J C

出版信息

Prostaglandins. 1985 Nov;30(5):867-77. doi: 10.1016/0090-6980(85)90015-2.

Abstract

PGE2 metabolism was examined in rabbit renal slices and cell suspensions from the outer medulla, enriched (TALH) and depleted (OMC) for the thick ascending limb of Henle's loop. Metabolism was negligible in intact cells, either OMC or TALH fractions. However, in OMC and TALH homogenates, transformation of PGE2 to PGF2 alpha by NADPH-dependent prostaglandin E-9 ketoreductase (PGE-9KR) was observed at a PGE2 concentration of 4 X 10(-9) M. This activity was not reversible and was enriched ten-fold in the TALH with 41% of PGE2 transformed to PGF2 alpha after 30 min incubation. PGF2 alpha formation from PGE2 could not be detected in homogenates of cortex, medulla or papilla. PGE-9KR activity, particularly in the thick ascending limb, may be a source of PGF2 alpha in urine.

摘要

在兔肾切片以及来自髓质外层的细胞悬液中检测了前列腺素E2（PGE2）的代谢情况，这些细胞悬液分别富含（亨氏袢厚升支，TALH）和缺乏（外髓集合管，OMC）亨氏袢厚升支。在完整细胞中，无论是OMC还是TALH组分，代谢都可忽略不计。然而，在OMC和TALH匀浆中，在PGE2浓度为4×10⁻⁹ M时，观察到依赖烟酰胺腺嘌呤二核苷酸磷酸（NADPH）的前列腺素E-9酮还原酶（PGE-9KR）将PGE2转化为前列腺素F2α（PGF2α）。这种活性是不可逆的，并且在TALH中富集了10倍，孵育30分钟后，41%的PGE2转化为PGF2α。在皮质、髓质或乳头的匀浆中未检测到由PGE2形成PGF2α。PGE-9KR活性，尤其是在厚升支中的活性，可能是尿液中PGF2α的一个来源。