HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 286/1/R206    most recent 00340.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Raman, P. Articles by Spurlock, M. E. Search for Related Content PubMed PubMed Citation Articles by Raman, P. Articles by Spurlock, M. E.

APPETITE, OBESITY AND METABOLISM

Regulation of hepatic glucose metabolism by leptin in pig and rat primary hepatocyte cultures

Department of Animal Sciences, Comparative Medicine Program, Purdue University, West Lafayette, Indiana 47907-1151

Submitted 20 June 2003 ; accepted in final form 25 August 2003

Direct effects of leptin on gluconeogenesis in rat hepatocytes are equivocal, and model systems from other species have not been extensively explored in assessing the regulation of glucose metabolism by leptin. Therefore, the goal of the present study was to compare the effects of leptin on gluconeogenesis in pig and rat hepatocyte cultures as well as to investigate an underlying mechanism of action at the level of phosphoenolpyruvate carboxykinase (PEPCK). In rat hepatocytes, leptin exposure (3 h, 50 and 100 nM) attenuated glucagon-stimulated hepatic gluconeogenesis by 35 and 38% (P < 0.05), respectively. However, leptin did not produce any significant acute effect in pig hepatocytes. Leptin exposure for 24 h failed to produce any significant effect on gluconeogenesis in either rat or pig hepatocytes cultured in the presence of glucagon or dexamethasone. Mechanistically, there was a 25-35% decrease (P < 0.05) in glucagon-induced PEPCK mRNA levels in rat but not pig hepatocytes cultured with leptin. This effect on PEPCK mRNA was not due to an alteration in the relative abundance of the leptin receptor or the ability of PEPCK to respond to cAMP. The nonuniformity of the effects of leptin on gluconeogenesis in pig and rat hepatocytes indicates differences in leptin action between species. Furthermore, the unique action of leptin in porcine hepatocytes points to the utility of this model system for biomedical research and also underscores the value of comparative studies.

hepatocytes; phosphoenolpyruvate carboxykinase; receptor

This article has been cited by other articles:

				T. G. Ramsay and M. P. Richards Leptin and leptin receptor expression in skeletal muscle and adipose tissue in response to in vivo porcine somatotropin treatment J Anim Sci, November 1, 2005; 83(11): 2501 - 2508. [Abstract] [Full Text] [PDF]

				K. Tomita, T. Azuma, N. Kitamura, G. Tamiya, S. Ando, H. Nagata, S. Kato, S. Inokuchi, T. Nishimura, H. Ishii, et al. Leptin deficiency enhances sensitivity of rats to alcoholic steatohepatitis through suppression of metallothionein Am J Physiol Gastrointest Liver Physiol, November 1, 2004; 287(5): G1078 - G1085. [Abstract] [Full Text] [PDF]