Adaptive response of equine intestinal Na+/glucose co-transporter (SGLT1) to an increase in dietary soluble carbohydrate
Tóm tắt
Experimental and epidemiological evidence suggests that consumption of hydrolyzable carbohydrate, hCHO (grain), by horses is an important risk factor for colic, a common cause of equine mortality. It is unknown whether the small intestinal capacity to digest hCHO and/or to absorb monosaccharides is limiting, or even if horses can adapt to increased carbohydrate load. We investigated changes in the brush-border membrane carbohydrate digestive enzymes and glucose absorptive capacity of horse small intestine in response to increased hCHO. Expression of the Na+/glucose co-transporter, SGLT1, was assessed by Western blotting, immunohistochemistry, Northern blotting, QPCR, and Na+-dependent d-glucose transport. Glucose transport rates, SGLT1 protein, and mRNA expression were all 2-fold higher in the jejunum and 3- to 5-fold higher in the ileum of horses maintained on a hCHO-enriched diet compared to pasture forage. Activity of the disaccharidases was unaltered by diet. In a well-controlled study, we determined SGLT1 expression in the duodenal and ileal biopsies of horses switched, gradually over a 2-month period, from low (<1.0 g/kg bwt/day) to high hCHO (6.0 g/kg bwt/day) diets of known composition. We show that SGLT1 expression is enhanced, with time, 2-fold in the duodenum and 3.3-fold in the ileum. The study has important implications for dietary management of the horse.
Tài liệu tham khảo
Affleck JA, Heliwell PA, Kellett GL (2003) Immunohistochemical detection of GLUT2 at the rat intestinal brush-border membrane. J Histochem Cytochem 51:1567–1574
Argenzio RA, Hintz HF (1972) Effect of diet on glucose entry and oxidation rates in ponies. J Nutr 102:897–892
Bergman EN (1990) Energy contributions of volatile fatty acids from the gastrointestinal tract in various species. Physiol Rev 70:567–590
Bracamonte JL, Boure LP, Geor RJ, Runciman JR, Nykamp SG, Cruz AM, Teeter MG, Waterfall HL (2008) Evaluation of a laparoscopic technique for collection of serial full-thickness small intestinal biopsy specimens in standing sedated horses. Am J Vet Res 69:431–439
Brannon RM (1990) Adaptation of exocrine pancreas to diet. Ann Rev Nutr 10:85–105
Buddington RK, Chen JW, Diamond JM (1991) Dietary regulation of intestinal brush-border sugar and amino acid transport in carnivores. Am J Physiol 261:R794–R801
Buddington RK, Rashmir-Raven AM (2002) Carbohydrate digestion by the horse: is there a limiting factor. Equine Vet J 34:326–327
Clarke LL, Roberts MC, Argenzio RA (1990) Feeding and digestive problems in horses. physiologic responses to a concentrated meal. Vet Clin North Am Equine Pract 6:433–450
Cui X-L, Schlesier EL, Cerqueira C, Ferraris RP (2005) Fructose induced increases in neonatal rat intestinal fructose transporter involve the PI3-kinase/Akt signaling pathway. Am J Physiol Gastrointest Liver Physiol 288:G1310–G1320
Daly K, Stewart C, Flint HJ, Shirazi-Beechey SP (2001) Bacterial diversity within the equine large intestine as revealed by molecular analysis of cloned 16S rRNA genes. FEMS Micrbiol Ecol 38:141–151
Dyer J, Fernandez-Castaño Merediz E, Salmon KSH, Proudman CJ, Edwards GB, Shirazi-Beechey SP (2002) Molecular characterisation of carbohydrate digestion and absorption in the equine small intestine. Equine Vet J 34:349–358
Dyer J, Wood IS, Palejwala A, Ellis A, Shirazi-Beechey SP (2002) Expression of monosaccharide transporters in intestine of diabetic humans. Am J Physiol Gastrointest Liver Physiol 282:G241–G248
Dyer J, Daly K, Salmon KS, Arora DK, Kokrashvili Z, Margolskee RF, Shirazi-Beechey SP (2007) Intestinal glucose sensing and regulation of intestinal glucose absorption. Biochem Soc Trans 35:1191–1194
Fernandez-Castaño Merediz E, Dyer J, Salmon KSH, Shirazi-Beechey SP (2004) Molecular characterisation of fructose transport in equine small intestine. Equine Vet J 36:532–538
Ferraris RP, Diamond JM (1989) Specific regulation of intestinal nutrient transporters by their dietary substrates. Annu Rev Physiol 51:125–141
Goodson J, Tyznik WJ, Cline JH, Dehority BA (1988) Effects of an abrupt diet change from hay to concentrate on microbial numbers and physical environment in the caecum of the pony. Appl Env Microbiol 54:1946–1950
Hillyer MH, Mair TS (1997) Recurrent colic in the mature horse: a retrospective review of 58 cases. Equine Vet J 29:421–424
Hintz HF, Cymbaluk NF (1994) Nutrition of the horse. Ann Rev Nutr 14:243–267
Hoffman RM, Wilson JA, Kronfeld DS, Cooper WL, Lawrence LA, Sklan D, Harris PA (2001) Hydrolyzable carbohydrates in pasture, hay, and horse feeds: direct assay and seasonal variation. J Anim Sci 79:500–506
Hudson JM, Cohen ND, Gibbs PG, Thompson JA (2001) Feeding practices associated with colic in horses. J Am Vet Med Assoc 219:1419–1425
Kellett GL, Helliwell PA (2000) The diffusive component of intestinal glucose absorption is mediated by the glucose-induced recruitment of GLUT2 to the brush border membrane. Biochem J 350:155–162
Kienzle E, Radicke S (1993) Effect of diet on maltase, sucrose and lactase in the small intestinal mucosa of horse. J Anim Physiol Anim Nutr 70:97–103
Kienzle E, Radicke S, Landes E, Kleffken D, Illenseer M, Meyer H (1994) Activity of amylase in gastrointestinal tract of horse. J Anim Physiol Anim Nutr 72:234–241
Lescale-Matys L, Dyer J, Scott D, Freeman TC, Wright EM, Shirazi-Beechey SP (1993) Regulation of the ovine intestinal Na+-glucose co-transporter (SGLT1) is dissociated from mRNA abundance. Biochem J 291:435–440
Lopes MAF, White NA II, Crisman MV, Ward DL (2004) Effects of feeding large amounts of grain on colonic contents and faeces in horses. Am J Vet Res 65:687–694
Mace OJ, Affleck J, Patel N, Kellett GL (2007) Sweet taste receptors in rat small intestine stimulate glucose absorption through apical GLUT2. J Physiol 582:379–392
Mair TS, Hillyer MH (1997) Chronic colic in the mature horse: a retrospective review of 106 cases. Equine Vet J 29:415–420
Margolskee RF, Dyer J, Kokrashvili Z, Salmon KSH, Ilegems E, Daly K, Maillet EL, Ninomiya Y, Mosinger B, Shirazi-Beechey SP (2007) T1R3 and gustducin in gut sense sugars to regulate expression of Na-glucose cotransporter 1. Proc Natl Acad Sci U S A 104:15075–15080
Oatey PB, Van Weering DHJ, Dobson SP, Gould GW, Tavaré JM (1997) GLUT 4 vesicle dynamics in living 3T3 L1 adipocytes visualized with green-fluorescent protein. Biochem J 327:637–642
Potter GD, Arnold FF, Householder DD, Hansen DH, Brown KM (1992) Digestion of starch in the small and large intestine of the equine. Pferdeheilkunde 1:107–111
Pratt SE, Geor RJ, McCutcheon LJ (2006) effects of dietary energy source and physical conditioning on insulin sensitivity and glucose tolerance in standardbred horses. Equine Vet J Suppl 36:579–584
Richards N, Choct M, Hinch GN, Rowe JB (2004) Examination of the use of exogenous α-amylase and amyloglucoside to enhance starch digestion in the small intestine of horse. Anim Feed Sci Technol 114:295–305
Roberts MC (1974) Amylase activity in the small intestine of the horse. Res Vet Sci UK 17:400–401
Roberts MC, Hill FWG, Kidder DE (1974) The development and distribution of small intestinal disaccharidases in the horse. Res Vet Sci 17:42–48
Roberts MC (1975) Carbohydrate digestion and absorption in the equine small intestine. J S Afr Vet Ass 46:19–27
Salmon KSH, Dyer J, Fernandez-Castaño Merediz E, Shirazi-Beechey SP (2002) Absorption of monosaccharides in equine small intestine; adaptive response to dietary change. Gastroenterol 122:T1316
Shirazi-Beechey SP, Davies AG, Tebbutt K, Dyer J, Ellis A, Taylor P, Fairclough P, Beechey RB (1990) Preparation and properties of brush-border membrane vesicles from human small intestine. Gastroenterol 98:676–685
Shirazi-Beechey SP (1995) Molecular biology of intestinal glucose transport. Nutr Res Rev 8:27–41
Shirazi-Beechey SP (1996) Intestinal sodium-dependent D-glucose co-transporter: dietary regulation. Proc Nutr Soc 55:167–178
Solberg DH, Diamond JM (1987) Comparison of different dietary sugars as inducers of intestinal sugar transporters. Am J Physiol 252:G574–G584
Thurmond DC, Ceresa BP, Okada S, Elmendorf JS, Coker K, Pessin JE (1998) Regulation of insulin stimulated GLUT4 translocation by Munc18c in 3T3L1 adipocytes. J Biol Chem 273:33876–33883
Tinker MK, White NA, Lessard P, Thatcher CD, Pelzer KD, Davis B, Carmel DK (1997) Prospective study of equine colic risk factors. Equine Vet J 29:454–458
Trimble ER, Rausch U, Kern HF (1987) Changes in individual rates of pancreatic enzyme and isoenzyme biosynthesis in the obese Zucker rat. Biochem J 248:771–777
Wood IS (1995) Molecular characterisation of intestinal nutrient transporters. PhD thesis, University of Wales, Aberystwyth
Wood IS, Dyer J, Hofmann RR, Shirazi-Beechey SP (2000) Expression of Na+/glucose co-transporter (SGLT1) in the intestine of domestic and wild ruminants. Pflugers Archiv 441:155–162
Wright EM, Martin MG, Turk E (2003) Intestinal absorption in health and disease—sugars. Best Practice & Res Clin Gastroenterol 117:943–956