+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Reduced intestinal epithelial cell brush border membrane calcium transport in spontaneously hypertensive rats



Reduced intestinal epithelial cell brush border membrane calcium transport in spontaneously hypertensive rats



Journal of Hypertension 17(6): 777-784



Objective The present study aimed to determine whether there were alterations in intestinal calcium homeostasis in the spontaneously hypertensive rats (SHR) and to identify at which interface of the intestinal epithelial cell (brush border or basolateral) this occurs. Design Controversy exists as to whether intestinal calcium transport is altered in association with hypertension. Studies using perfused duodenal segments of the SHR have shed little light on the problem; other studies have only measured calcium transport in brush border membrane vesicles. This study allows specific focus on calcium transport mechanisms at both the brush border and basolateral membrane using simultaneously prepared membrane vesicles. Methods Calcium transport was studied by measuring radiolabelled calcium (45Ca) uptake in isolated brush border and basolateral membrane vesicles, prepared from the small intestines of SHR and Wistar-Kyoto (WKY) rats. Calcium uptake was measured when vesicles were incubatedin solutions containing different concentrations of ATP and calcium. Orientation and membrane marker assays were used to confirm the phenotypes of the two membrane vesicle preparations. Results ATP-dependent calcium efflux was only observed in the basolateral membrane, which contains the Ca2+-ATPase pump. SHR brush border membrane vesicles displayed no significant increase in calcium incorporation, whereas WKY brush border vesicles showed a 500% increase in uptake (ANOVA, P < 0.05, n = 7). Conclusions This study indicates that deficiencies exist in SHR intestinal calcium transport at the brush border membrane of intestinal epithelial cells. While further studies are required to ascertain the exact mechanisms involved, postulated deficiencies in the actions of calcium regulating hormones at this membrane suggest the need for concurrent intake of a calcitrophic agent to assist calcium uptake at the brush border membrane.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 011260236

Download citation: RISBibTeXText

PMID: 10459875

DOI: 10.1097/00004872-199917060-00009


Related references

Intestinal calcium transport in spontaneously hypertensive rat shr and their genetically matched wistar kyoto rat wky studies in brush border bbm and basolateral membrane blm. Gastroenterology 96(5 Part 2): A466, 1989

Increased brush-border membrane calcium transport in the intestine, but not the kidney tubule, of spontaneously hypertensive rats. American Journal of Hypertension 6(7 Pt 1): 593-601, 1993

Reduced duodenal enterocyte calcium fluxes, decreased 1,25(OH)2D3 and abnormal brush border membrane in the spontaneously hypertensive rat. Progress in Clinical and Biological Research 252: 365-369, 1988

Transport system of renal brush border membrane in spontaneously hypertensive rats. Nihon Jinzo Gakkai Shi 30(6): 767-775, 1988

Reduced duodenal enterocyte calcium fluxes decreased 1 25 dihydroxyvitamin d3 and abnormal brush border membrane in the spontaneously hypertensive rat. Bronner, F And M Peterlik (Ed ) Progress in Clinical And Biological Research, Vol 252 Cellular Calcium And Phosphate Transport in Health And Disease; Third International Workshop on Calcium And Phosphate Transport Across Biomembranes, Vienna, Austria, March 1-4, 1987 Xxiii+426p Alan R Liss, Inc : New York, New York, Usa Illus 365-370, 1988

Intestinal brush border calcium uptake in spontaneously hypertensive rats and their genetically matched WKY rats. Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine 196(1): 54-60, 1991

Decreased monosaccharide transport in renal brush-border membrane vesicles of spontaneously hypertensive rats. Cellular and Molecular Life Sciences 57(1): 165-174, 2000

Intestinal transport of phosphate by brush border membranes bbm of spontaneously hypertensive rats shr and genetically matched controls wky rats role of ontogeny and vitamin d. Gastroenterology 96(5 Part 2): A13, 1989

Increased calcium absorption in prehypertensive spontaneously hypertensive rat. Role of serum 1,25-dihydroxyvitamin D3 levels and intestinal brush border membrane fluidity. Journal of Clinical Investigation 78(4): 1083-1090, 1986

Calcium uptake into enterocyte brush-border membrane vesicles is greater in spontaneously hypertensive than in normotensive control rats. Contributions to Nephrology 90: 42-48, 1991

Sodium transport by isolated renal brush border membrane vesicles bbmv from spontaneously hypertensive rats shr increased sodium proton countertransport ct. Kidney International 31(1): 309, 1987

Magnesium uptake by intestinal brush-border membranes of spontaneously hypertensive rats. Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine 201(1): 119-124, 1992

Magnesium uptake in intestinal brush-border vesicles of spontaneously hypertensive rats. Journal of Physiology 406: 116P, 1988

Increased sodium-dependent D-glucose transport in the jejunal brush-border membrane of spontaneously hypertensive rat. Pfluegers Archiv European Journal Of Physiology. 434(2): 329-335, 1996