碳酸氢盐在兔回肠隐窝-绒毛轴上转运的定位

Localization of bicarbonate transport along the crypt-villus axis in rabbit ileum.

作者信息

Minhas B S, Field M

机构信息

Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York.

出版信息

Gastroenterology. 1994 Jun;106(6):1562-7. doi: 10.1016/0016-5085(94)90411-1.

DOI:10.1016/0016-5085(94)90411-1

PMID:8194702

Abstract

BACKGROUND/AIMS: HCO3- can be absorbed as well as secreted in the rabbit ileum. With 25 mmol/L HCO3- on the serosal side only, a serosa-to-mucosa flux (Jsm) is found; with 25 mmol/L on the mucosal side only, epinephrine elicits a mucosa-to-serosa flux (Jms). This study aimed to localize these two processes along the crypt-villus axis.

METHODS

Excised ileal segments were exposed luminally to 2 mol/L Na2SO4 (hypertonic treatment) or to isotonic Ringer's solution for 15 minutes. Mucosa was then chamber-mounted, and measurements were made of Jsm or Jms and of short-circuit current (Isc) responses to glucose plus alanine and to either theophylline or epinephrine.

RESULTS

With HCO3-/CO2 added to the serosal side only, hypertonically treated tissues showed a 22% decline in Jsm; a 25% decline in Isc response to theophylline; and a 71% decline in Isc response to glucose plus alanine compared with control. With HCO3-/CO2 added to the mucosal side only, tissues showed 92% and 87% declines in Jms and Isc responses to epinephrine, respectively, and a 87% decline in Isc response to glucose plus alanine. Histological examination showed destruction of villus caused by hypertonic treatment but sparing of crypt cells.

CONCLUSIONS

Both HCO3- and Cl- are secreted mainly by crypt cells and absorbed mainly by villus cells.

摘要

背景/目的：在兔回肠中，HCO3- 既可以被吸收也可以被分泌。仅在浆膜侧存在25 mmol/L HCO3- 时，可发现从浆膜到黏膜的通量（Jsm）；仅在黏膜侧存在25 mmol/L时，肾上腺素可引发从黏膜到浆膜的通量（Jms）。本研究旨在沿隐窝 - 绒毛轴定位这两个过程。

方法

将切除的回肠段腔内暴露于2 mol/L Na2SO4（高渗处理）或等渗林格氏液中15分钟。然后将黏膜安装在小室中，测量Jsm或Jms以及对葡萄糖加丙氨酸和茶碱或肾上腺素的短路电流（Isc）反应。

结果

仅在浆膜侧添加HCO3-/CO2时，高渗处理的组织与对照相比，Jsm下降22%；对茶碱的Isc反应下降25%；对葡萄糖加丙氨酸的Isc反应下降71%。仅在黏膜侧添加HCO3-/CO2时，组织对肾上腺素的Jms和Isc反应分别下降92%和87%，对葡萄糖加丙氨酸的Isc反应下降87%。组织学检查显示高渗处理导致绒毛破坏，但隐窝细胞未受影响。