| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
2 Department of Metabolic Diseases, Hoffmann-La Roche Inc., Nutley, NJ, USA
* To whom correspondence should be addressed. E-mail: masakazu.shiota{at}vanderbilt.edu.
The rate of liver glucokinase (GK) translocation from the nucleus to the cytoplasm in response to intraduodenal glucose infusion and the effect of physiological rises of plasma glucose and/or insulin on GK translocation were examined in 6 h fasted conscious rats. Intraduodenal glucose infusion (28 mg.kg-1.min-1 after a priming dose at 500 mg/kg) elevated blood glucose levels (mg/dl) in the artery and portal vein from 90 ± 3 and 87 ± 3 to 154 ± 4 and 185 ± 4, respectively, at 10 min. At 120 min the levels had decreased to 133 ± 6 and 156 ± 5, respectively. Plasma insulin levels (ng/ml) in the artery and the portal vein rose from 0.7 ± 0.1 and 1.8 ± 0.3 to 11.8 ± 1.5 and 20.2 ± 2.0 at 10 min, respectively, and 12.4 ± 3.1 and 18.0 ± 4.8 at 30 min. GK was rapidly exported from the nucleus as determined by measuring the ratio of the nuclear to the cytoplasmic immunofluorescence (N/C) of GK (2.9 ± 0.3 at 0 min to 1.7 ± 0.2 at 10 min, 1.5 ± 0.1 at 20 min, 1.3 ± 0.1 at 30 min, and 1.3 ± 0.1 at 120 min). When plasma glucose (arterial; mg/dl) and insulin (arterial; ng/ml) levels were clamped for 30 min at 93 ± 7 and 0.7 ± 0.1, 81 ± 5 and 8.9 ± 1.3, 175 ± 5 and 0.7 ± 0.1, or 162 ± 5 and 9.2 ± 1.5, the N/C of GK was 3.0 ± 0.5, 1.8 ± 0.1, 1.5 ± 0.1, and 1.2 ± 0.1, respectively. The N/C of GK regulatory protein (GKRP) did not change in response to the intraduodenal glucose infusion or the rise in plasma glucose and/or insulin levels. The results suggest that GK, but not GKRP, translocates rapidly in a manner that corresponds with changes in the hepatic glucose balance in response to glucose ingestion in vivo. Additionally, the translocation of GK is induced by the postprandial rise in plasma glucose and insulin.
This article has been cited by other articles:
|
|
 |
|
  J. J. Winnick, Z. An, M. C. Moore, C. J. Ramnanan, B. Farmer, M. Shiota, and A. D. Cherrington A physiological increase in the hepatic glycogen level does not affect the response of net hepatic glucose uptake to insulin Am J Physiol Endocrinol Metab, August 1, 2009; 297(2): E358 - E366. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Zheng, V. Ionut, V. Mooradian, D. Stefanovski, and R. N. Bergman Exenatide Sensitizes Insulin-Mediated Whole-Body Glucose Disposal and Promotes Uptake of Exogenous Glucose by the Liver Diabetes, February 1, 2009; 58(2): 352 - 359. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. P. Torres, R. L. Catlin, R. Chan, Y. Fujimoto, N. Sasaki, R. L. Printz, C. B. Newgard, and M. Shiota Restoration of Hepatic Glucokinase Expression Corrects Hepatic Glucose Flux and Normalizes Plasma Glucose in Zucker Diabetic Fatty Rats Diabetes, January 1, 2009; 58(1): 78 - 86. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 O. Anderka, J. Boyken, U. Aschenbach, A. Batzer, O. Boscheinen, and D. Schmoll Biophysical Characterization of the Interaction between Hepatic Glucokinase and Its Regulatory Protein: IMPACT OF PHYSIOLOGICAL AND PHARMACOLOGICAL EFFECTORS J. Biol. Chem., November 14, 2008; 283(46): 31333 - 31340. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Donati, G. Recchia, G. Cavallini, and E. Bergamini Effect of Aging and Anti-Aging Caloric Restriction on the Endocrine Regulation of Rat Liver Autophagy J. Gerontol. A Biol. Sci. Med. Sci., June 1, 2008; 63(6): 550 - 555. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Stafford, F. Yu, R. Printz, A. H. Hasty, L. L. Swift, and K. D. Niswender Central Nervous System Neuropeptide Y Signaling Modulates VLDL Triglyceride Secretion Diabetes, June 1, 2008; 57(6): 1482 - 1490. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. A. Payne, C. Arden, A. J. Lange, and L. Agius Contributions of glucokinase and phosphofructokinase-2/fructose bisphosphatase-2 to the elevated glycolysis in hepatocytes from Zucker fa/fa rats Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2007; 293(2): R618 - R625. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J.-S. Shin, T. P. Torres, R. L. Catlin, E. P. Donahue, and M. Shiota A defect in glucose-induced dissociation of glucokinase from the regulatory protein in Zucker diabetic fatty rats in the early stage of diabetes Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2007; 292(4): R1381 - R1390. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Fujimoto, T. P. Torres, E. P. Donahue, and M. Shiota Glucose Toxicity Is Responsible for the Development of Impaired Regulation of Endogenous Glucose Production and Hepatic Glucokinase in Zucker Diabetic Fatty Rats Diabetes, September 1, 2006; 55(9): 2479 - 2490. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Baltrusch, F. Francini, S. Lenzen, and M. Tiedge Interaction of Glucokinase With the Liver Regulatory Protein Is Conferred by Leucine-Asparagine Motifs of the Enzyme Diabetes, October 1, 2005; 54(10): 2829 - 2837. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Shiota, P. Galassetti, K. Igawa, D. W. Neal, and A. D. Cherrington Inclusion of low amounts of fructose with an intraportal glucose load increases net hepatic glucose uptake in the presence of relative insulin deficiency in dog Am J Physiol Endocrinol Metab, June 1, 2005; 288(6): E1160 - E1167. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Fujimoto, E. P. Donahue, and M. Shiota Defect in glucokinase translocation in Zucker diabetic fatty rats Am J Physiol Endocrinol Metab, September 1, 2004; 287(3): E414 - E423. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
