ABSTRACT
Objective To investigate the effect of astragalus membranaceus on the ultrastructure of small intestinal epithelial cells in rabbits with hemorrhagic shock. Methods Twenty-four New Zealand white rabbits of both sexes weighing 2-3 kg were randomly divided into 3 equal groups : (A) control group received normal saline iv ( n = 8); (B) group HI received astragalus membranaceus 20 mg? kg-1 iv ( n = 8); ( C) group H2 received astragalus membranaceus 10 mg?kg-1 iv ( n = 8 ). Animal model of hemorrhagic shock-resuscitation was established according to Wigger's. A strip of small intestine, 10 cm in length was taken from distal end of ileum for electron microscopic examination. The two-dimensional structural parameters and three-dimensional structural parameters of mitochondria were calculated. Results (1) Morphological changes of small intestine : in group H1 epithelial cells were orderly arranged, with relatively normal mitochondria and intestinal villi were slender and orderly; in group H2 the nuclei in epithelial cells were dwindled, the intestinal villi were thin and short and unorderly arranged with slightly swelled mitochondria and blurring ridges. Endoplasmatic reticulum was dilated; in group C the gaps between epithelial cells widened. There were a lot of apoptotic cells. Microvilli were thin and short and swelled. Mitochondria were swelled with broken ridges. Endoplasmatic reticulum was severely dilated. (2) Structural parameters of mitochondria : in group C there were least mitochondria and the swelling of mitochondria was severe; in group H1 there were plenty of mitochondria and the swelling was slightest; in group H2 the changes in mitochondria were between group C and H1. Conclusion Astragalus membranaceus can protect small intestine from ischemia/reperfusion injury in a dose-dependent manner.