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Journal of Obesity
Volume 2011, Article ID 516842, 8 pages
Research Article

Hepatoportal Leptin Sensors and Their Reflex Effects on Autonomic Outflow in the Rat

School of Medicine, Niigata University, Asahimachidori-1, Chuouku, Niigata 951-8510, Japan

Received 28 May 2010; Accepted 22 December 2010

Academic Editor: A. Halpern

Copyright © 2011 Akira Niijima. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Afferent nerve signals were recorded from a peripheral cut end of the small nerve bundle of the hepatic branch of the vagus nerve in anesthetized rats. An injection of leptin (100 pg, 0.1 mL) into the portal vein facilitated the afferent activity. The response was dose dependent. Further, an intravenous (IV) injection of leptin (1 ng, 0.1 mL) facilitated the efferent nerve activity of the sympathetic nerve to the adrenal gland and suppressed that of the celiac branch of the vagus nerve. In hepatic vagotomized rats, no change in efferent activity of the adrenal sympathetic nerve nor celiac branch of the vagus nerve was observed following iv administration of leptin. These observations suggest that leptin sensors in the hepatoportal region play a role in reflex modulation of autonomic outflow in relation to metabolic functions.