Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-09T01:34:36.279Z Has data issue: false hasContentIssue false
  • English
  • Français

Meal-induced insulin sensitization in conscious and anaesthetized rat models comparing liquid mixed meal with glucose and sucrose

Published online by Cambridge University Press:  08 March 2007

Parissa Sadri ,
Maria A. G. Reid ,
Ricardo A. Afonso ,
Joshua Schafer ,
Dallas J. Legare ,
M. Paula Macedo  and
W. Wayne Lautt
Parissa Sadri
Affiliation:
Department of Pharmacology & Therapeutics, Faculty of Medicine, University of Manitoba, A210 – 753 McDermot Avenue, Winnipeg, Manitoba, CanadaR3E 0T6
Maria A. G. Reid
Affiliation:
Department of Pharmacology & Therapeutics, Faculty of Medicine, University of Manitoba, A210 – 753 McDermot Avenue, Winnipeg, Manitoba, CanadaR3E 0T6
Ricardo A. Afonso
Affiliation:
Departamento de Fisiologia – FCM-UNL, Campo Martires da Patria 130, 1169-056 Lisbon, Portugal
Joshua Schafer
Affiliation:
Department of Pharmacology & Therapeutics, Faculty of Medicine, University of Manitoba, A210 – 753 McDermot Avenue, Winnipeg, Manitoba, CanadaR3E 0T6
Dallas J. Legare
Affiliation:
Department of Pharmacology & Therapeutics, Faculty of Medicine, University of Manitoba, A210 – 753 McDermot Avenue, Winnipeg, Manitoba, CanadaR3E 0T6
M. Paula Macedo
Affiliation:
Departamento de Fisiologia – FCM-UNL, Campo Martires da Patria 130, 1169-056 Lisbon, Portugal
W. Wayne Lautt*
Affiliation:
Department of Pharmacology & Therapeutics, Faculty of Medicine, University of Manitoba, A210 – 753 McDermot Avenue, Winnipeg, Manitoba, CanadaR3E 0T6
*
*Corresponding author: Dr W. Wayne, fax +1 204 975 7784, email [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We have recently shown that meal-induced insulin sensitization (MIS) occurs after feeding and decreases progressively to insignificance after 24h of fasting and is caused by action of a hepatic insulin sensitizing substance (HISS). In order to carry out quantitative studies of MIS, some standardized meal intake is required. Our objective was to establish animal models to be tested in both the conscious and anaesthetized state using intragastric injection of liquid meals in order to quantify MIS. Insulin sensitivity was assessed before and 90min after the meal using the rapid insulin sensitivity test (RIST) which is a transient euglycaemic clamp. Rats tested in the conscious state were instrumented under anaesthesia 6–9d prior to testing with catheters in the carotid artery, jugular vein and stomach. Meals, injected into the stomach, consisted of a liquid mixed meal, sucrose, glucose or water. The glucose sequestration in response to insulin increased by 90% and 61% following the liquid mixed meal (10ml/kg) in conscious and anaesthetized rats, respectively. Glucose, sucrose and water did not effectively activate MIS. MIS was completely reversed in the conscious model by atropine and completely prevented from developing in the anaesthetized model that had previously undergone hepatic denervation. Gastric administration of a liquid mixed meal but not glucose or sucrose is capable of activating MIS for purposes of mechanistic studies and quantification of the MIS process. The feeding signal is mediated by the hepatic parasympathetic nerves.

Keywords

HISSRISTInsulin sensitivityMealFeedingSucroseGlucose
Type
Research Article
Information
British Journal of Nutrition , Volume 95 , Issue 2 , February 2006 , pp. 288 - 295
Copyright
Copyright © The Nutrition Society 2006

References

Guarino, MP, Afonso, RA, Raimundo, N, Raposo, JF & Macedo, MPHepatic glutathione and nitric oxide are critical for hepatic insulin-sensitizing substance action. Am J Physiol Gastrointest Liver Physiol 2003 284 G588–G594CrossRefGoogle ScholarPubMed
Latour, MG & Lautt, WWInsulin sensitivity regulated by feeding in the conscious unrestrained rat. Autonom Neurosci 2002 95 125–130CrossRefGoogle Scholar
Lautt, WWThe HISS story overview: a novel hepatic neurohumoral regulation of peripheral insulin sensitivity in health and diabetes. Can J Physiol Pharmacol 1999 77 553–562CrossRefGoogle ScholarPubMed
Lautt, WWA proposed new paradigm for insulin resistance. Metab Syndr Relat Dis 2003a 1 261–270CrossRefGoogle ScholarPubMed
Lautt, WWPractice and principles of pharmacodynamic determination of HISS-dependent and HISS-independent insulin action: methods to quantitate mechanisms of insulin resistance. Med Res Rev 2003b 23 1–14CrossRefGoogle ScholarPubMed
Lautt, WWA new paradigm for diabetes and obesity: the hepatic insulin sensitizing substance (HISS) hypothesis. J Pharmacol Sci 2004 95 9–17CrossRefGoogle ScholarPubMed
Lautt, WW, Macedo, MP, Sadri, P, Takayama, S, Ramos, FD & Legare, DJHepatic parasympathetic (HISS) control of insulin sensitivity determined by feeding and fasting. Am J Physiol Gastrointest Liver Physiol 2001 281 G29–G36CrossRefGoogle ScholarPubMed
Lautt, WW, Wang, X, Sadri, P, Legare, DJ & Macedo, MPRapid insulin sensitivity test (RIST). Can J Physiol Pharmacol 1998 76 1080–1086CrossRefGoogle ScholarPubMed
Moore, MC, Sataka, S, Baranowski, B, Hsieh, P-S, Neal, DW & Cherrington, ADEffect of hepatic denervation on peripheral insulin sensitivity in conscious dogs. Am J Physiol Endocrinol Metab 2002 282 E286–E296CrossRefGoogle ScholarPubMed
Reid, MAG, Latour, MG, Legare, DJ, Rong, N & Lautt, WWComparison of the rapid insulin sensitivity test (RIST), the insulin tolerance test (ITT), and the hyperinsulinemic clamp (HIEC) to measure insulin action in rats. Can J Physiol Pharmacol 2002 80 811–818CrossRefGoogle ScholarPubMed
Reid, MAG & Lautt, WWPattern of insulin delivery affects HISS action and insulin resistance. Can J Physiol Pharmacol 2004 82 1068–1074CrossRefGoogle ScholarPubMed
Ribeiro, RT, Lautt, WW, Legare, DJ & Macedo, MPInsulin resistance induced by sucrose-feeding is due to an impairment of the hepatic parasympathetic nerves. Diabetologia 2005 48 976–983CrossRefGoogle Scholar
Sadri, P & Lautt, WWBlockade of hepatic nitric oxide synthase causes insulin resistance. Am J Physiol 1999 277 G101–G108Google ScholarPubMed
Sadri, P & Lautt, WWInsulin resistance caused by hepatic COX inhibition (abstract). Diabetes 2000 49 A245Google Scholar
Takayama, S, Legare, DJ & Lautt, WWDose-related atropineinduced insulin resistance: comparing intraportal versus intravenous administration. Proc West Pharmacol Soc 2000 43 33–34Google ScholarPubMed
Xie, H & Lautt, WWInduction of insulin resistance by cholinergic blockade with atropine in the cat. J Auton Pharmacol 1995 15 361–369CrossRefGoogle ScholarPubMed
Xie, H, Lautt, WWInsulin resistance of skeletal muscle produced by hepatic parasympathetic interruption. Am J Physiol 1996 270 E858–E863Google ScholarPubMed
Xie, H, Tsybenko, VA, Johnson, MV & Lautt, WWInsulin resistance of glucose response produced by hepatic denervations. Can J Physiol Pharmacol 1993 71 175–178CrossRefGoogle ScholarPubMed