Pharmacokinetics and pharmacodynamics of subcutaneously administered PYY3-36 and its analogues in vivo.

Background: Obesity is an emergent epidemic associated with morbidity, mortality, and psychosocial effects. One of the key gut hormones that controls appetite is peptide tyrosine-tyrosine 3-36 (PYY3-36) whose circulating half-life is only 8 min. A long-acting analogue of PYY3-36 would therefore have great potential as an antiobesity agent.

The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism.

Increased intake of dietary carbohydrate that is fermented in the colon by the microbiota has been reported to decrease body weight, although the mechanism remains unclear. Here we use in vivo(11)C-acetate and PET-CT scanning to show that colonic acetate crosses the blood-brain barrier and is taken up by the brain. Intraperitoneal acetate results in appetite suppression and hypothalamic neuronal activation patterning.

Intracerebroventricular administration of vasoactive intestinal peptide inhibits food intake.

Vasoactive intestinal peptide (VIP) is a 28 amino acid peptide expressed throughout the peripheral and central nervous systems. VIP and the VIP receptor VPAC(2)R are expressed in hypothalamic nuclei involved in the regulation of energy homeostasis. VIP has been shown to be involved in the regulation of energy balance in a number of non-mammalian vertebrates.