Postnatal development of gastric aromatase and portal venous estradiol-17 beta levels in male rats

作者:Kobayashi Hiroto; Yoshida Saori; Sun Ying Jie; Shirasawa Nobuyuki*; Naito Akira
来源:Journal of Endocrinology, 2013, 218(1): 117-124.
DOI:10.1530/JOE-13-0074

摘要

Gastric parietal cells synthesize and secrete estradiol-17 beta (E-2) into gastric veins joining the portal vein, and a large amount of gastric E-2 first binds to its receptors in the liver. However, the role of the gastric E-2 is not entirely clear during postnatal development. The objective of this study was to reveal the onset of aromatase and other steroid-synthesizing enzymes in the gastric mucosa; to determine the period of rising E-2 levels in the portal vein; and to further understand the relationship between gastric E-2 and liver estrogen receptor alpha (ER alpha). The immunoblot bands and the immunohistochemistry of gastric mucosa revealed that aromatase protein began to express itself at 20 days and then increased in the levels of aromatase protein from 20 days onward. Expression of mRNAs for gastric aromatase (Cyp19a1) and other steroid-synthesizing enzymes, 17 alpha-Hydroxylase (Cyp17a1) and 17 beta-hydroxysteroid dehydrogenase (HSD17 beta 3), also increased similar to the increment of aromatase protein. Portal venous E-2 levels were elevated after 20 days and increased remarkably between 23 and 30 days, similar to gastric aromatase mRNA levels. The E-2 level was approximately three times higher at 40 days than that at 20 days. The liver weight and Esr1 levels began to increase after 20 days and the increment was positively correlated with the change of portal venous E-2 levels. These findings suggest that some changes may occur around 20 days to regulate the gastric E-2 synthesis and secretion.

  • 出版日期2013-7