Low Molecular Weight Heparins Cross Rat Gastric Mucosa Mounted in an Ussing Chamber
Title:
Low Molecular Weight Heparins Cross Rat Gastric Mucosa Mounted in an Ussing Chamber
Author:
B. Moazed L.M. Hiebert
Appeared in:
International journal of pharmacology
Paging:
Volume 4 (2008) nr. 6 pages 431-442
Year:
2008
Contents:
The aim of this study was to determine if the stomach is a site for low molecular heparin (LMWH) absorption. Gastric mucosa was mounted in a Vertical Diffusion Ussing Chamber and the LMWHs, tinzaparin or reviparin, were added to the mucosal buffer at pH 7.4 or 4.0. Potential difference (PD), resistance and short circuit current (Isc) were measured across the mucosa. Buffers and tissues were analyzed for chemical LMWH and anti-factor Xa activity. The PD became more negative on LMWH addition when the mucosal side was compared to the serosal side. The PD returned to baseline following a lag period, which was greater at pH 4.0 versus 7.4. Changes in resistance were similar to those for PD. Isc increased with time at pH 7.4 but not pH 4.0, which was most dramatic for reviparin. LMWHs were recovered from serosal buffer and tissue and had anti-factor Xa activity at both pH 7.4 and 4.0 although amounts found in serosal buffer and rate of movement were greater at pH 7.4 versus 4.0. In conclusion, changes in PD, LMWH recovery and anti-factor Xa activity in serosal buffer indicate that LMWHs cross rat gastric mucosa. Changes in Isc suggest that active transport may depend on mucosal pH. Furthermore, LMWHs cross gastric mucosa under both neutral and acidic conditions, however transport is faster in a neutral environment suggesting that the stomach, with an acidic environment, may not be the main site for LMWH absorption in vivo.
Publisher:
Asian Network for Scientific Information (provided by DOAJ)
Journal description