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Coordinated, diurnal hexose transporter expression in rat small bowel: implications for small bowel resection.
Surgery 2008; 143(1):79-93S

Abstract

BACKGROUND

Hexose transporter mRNA and protein levels follow a diurnal rhythm in rat jejunum. Their coordinated expression and resultant function throughout the small bowel is not well understood. We hypothesized that hexose transporter levels and glucose absorption follow a coordinated, site-specific diurnal rhythm in rat duodenum and jejunum, but not in ileum.

METHODS

Sprague-Dawley rats were housed in a strictly maintained, 12-h, light/dark room [light 6 am to 6 pm] with free access to water and chow. Mucosa was harvested from duodenum, jejunum, and ileum at 3 am, 9 am, 3 pm, and 9 pm, and full thickness 1-cm segments were harvested at 9 am, and 9 pm (n = 6 for each segment at each time point). mRNA levels were determined by reverse-transcription, real-time polymerase chain reaction (n > or = 5), protein levels by semiquantitative Western blotting (n > or = 5), and transporter-mediated glucose uptake by everted sleeve technique (n = 6).

RESULTS

mRNA levels of SGLT1 and GLUT5 followed a temporally coordinated, diurnal rhythm in all 3 segments (P < .01), while mRNA for GLUT2 and protein levels for SGLT1 and GLUT2 varied diurnally only in duodenum and jejunum (P > .05) but not in ileum (P > .10). SGLT1 and GLUT5 mRNA induction decreased aborally. Baseline SGLT1 and GLUT5 mRNA levels and SLGT1 and GLUT2 protein levels did not vary aborally (P > .05 for all). GLUT2 mRNA baseline levels were decreased in ileum (P < .01). Glucose uptake varied diurnally in duodenum and jejunum with no difference in ileum. Transporter-mediated glucose uptake was greater in duodenum and jejunum compared with ileum.

CONCLUSION

Regulation of hexose absorption in rat small bowel seems to be site-specific and mediated by multiple mechanisms.

Authors+Show Affiliations

Department of Surgery, GI Research Unit, Alfred 2, St Mary's Hospital, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18154936

Citation

Houghton, Scott G., et al. "Coordinated, Diurnal Hexose Transporter Expression in Rat Small Bowel: Implications for Small Bowel Resection." Surgery, vol. 143, no. 1, 2008, pp. 79-93.
Houghton SG, Iqbal CW, Duenes JA, et al. Coordinated, diurnal hexose transporter expression in rat small bowel: implications for small bowel resection. Surgery. 2008;143(1):79-93.
Houghton, S. G., Iqbal, C. W., Duenes, J. A., Fatima, J., Kasparek, M. S., & Sarr, M. G. (2008). Coordinated, diurnal hexose transporter expression in rat small bowel: implications for small bowel resection. Surgery, 143(1), pp. 79-93.
Houghton SG, et al. Coordinated, Diurnal Hexose Transporter Expression in Rat Small Bowel: Implications for Small Bowel Resection. Surgery. 2008;143(1):79-93. PubMed PMID: 18154936.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Coordinated, diurnal hexose transporter expression in rat small bowel: implications for small bowel resection. AU - Houghton,Scott G, AU - Iqbal,Corey W, AU - Duenes,Judith A, AU - Fatima,Javairiah, AU - Kasparek,Michael S, AU - Sarr,Michael G, Y1 - 2007/12/03/ PY - 2006/11/08/received PY - 2007/06/20/revised PY - 2007/06/22/accepted PY - 2007/12/25/pubmed PY - 2008/1/10/medline PY - 2007/12/25/entrez SP - 79 EP - 93 JF - Surgery JO - Surgery VL - 143 IS - 1 N2 - BACKGROUND: Hexose transporter mRNA and protein levels follow a diurnal rhythm in rat jejunum. Their coordinated expression and resultant function throughout the small bowel is not well understood. We hypothesized that hexose transporter levels and glucose absorption follow a coordinated, site-specific diurnal rhythm in rat duodenum and jejunum, but not in ileum. METHODS: Sprague-Dawley rats were housed in a strictly maintained, 12-h, light/dark room [light 6 am to 6 pm] with free access to water and chow. Mucosa was harvested from duodenum, jejunum, and ileum at 3 am, 9 am, 3 pm, and 9 pm, and full thickness 1-cm segments were harvested at 9 am, and 9 pm (n = 6 for each segment at each time point). mRNA levels were determined by reverse-transcription, real-time polymerase chain reaction (n > or = 5), protein levels by semiquantitative Western blotting (n > or = 5), and transporter-mediated glucose uptake by everted sleeve technique (n = 6). RESULTS: mRNA levels of SGLT1 and GLUT5 followed a temporally coordinated, diurnal rhythm in all 3 segments (P < .01), while mRNA for GLUT2 and protein levels for SGLT1 and GLUT2 varied diurnally only in duodenum and jejunum (P > .05) but not in ileum (P > .10). SGLT1 and GLUT5 mRNA induction decreased aborally. Baseline SGLT1 and GLUT5 mRNA levels and SLGT1 and GLUT2 protein levels did not vary aborally (P > .05 for all). GLUT2 mRNA baseline levels were decreased in ileum (P < .01). Glucose uptake varied diurnally in duodenum and jejunum with no difference in ileum. Transporter-mediated glucose uptake was greater in duodenum and jejunum compared with ileum. CONCLUSION: Regulation of hexose absorption in rat small bowel seems to be site-specific and mediated by multiple mechanisms. SN - 1532-7361 UR - https://www.unboundmedicine.com/medline/citation/18154936/Coordinated_diurnal_hexose_transporter_expression_in_rat_small_bowel:_implications_for_small_bowel_resection_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0039-6060(07)00366-2 DB - PRIME DP - Unbound Medicine ER -