ANS/NUTRS 520February 28,2012

Ventromedial nucleus of hypothalamus

(leptin) Stimulation decreases feed intake Lesions increase feed intake

Lateral hypothalamus Stimulation increases feed intake Lesions decrease feed intake

http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/foodintake.html

◦ Satiety signals

◦ Energy balance

Absorbed compounds-or direct result of an absorbed compound

Fermentation products (VFA-mainly acetate, propionate)

Ammonia (urea)

Steroids, FSH, LH, PRL, ST-secondary effects

J Physiol Pharmacol. 2007 Dec;58 Suppl 6:23-52.

◦ 36 AA neural peptide◦ Secreted from hypothalamus◦ Increases feed intake◦ Stimulates fat production◦ Production may increase due to cold stress or

aggressive behavior (Nat Med. 13:7, 2007)

◦ 41 AA peptide produced in hypothalamus◦ Decreases feed intake

Signal of body energy (fat) and senses

energy balance Inhibits neuropeptide Y In fed state

◦ Correlates with body fat mass Fasted state (12-48 h)

◦ Rapid drop in leptin expression

Molecular Psychiatry (2005) 10, 132–146

J. Dairy Sci. 86:799-807

Released from enterocytes to stimulate release of enzymes and bile into duodenum

Stimulates release of GH from pituitary Signals energy status

Wertz-Lutz et al., 2006

Tahir et al., 2008

P metabolism in liver to glucose leads to

insulin release Increased insulin decreases DMI Dose VFA intravenously-no effect Infuse VFA into portal vein-decrease meal

size

Oba and Allen, J Nutr 133:1094

Bradford and Allen, 2007 JDS 90:2305

Bradford and Allen, 2007 JDS 90:2305