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Is there appetite after GLP-1 and PACAP?
1Department of General and Human Biochemistry, Université Libre de Bruxelles, Brussels, Belgium.
Annals of the New York Academy of Sciences
|February 3, 1999
Summary
New anti-obesity drugs require enhanced hypothalamic satiety signaling and NPY antagonism. Glucagon-like peptide-1 (GLP-1) and Pituitary adenylate cyclase-activating polypeptide (PACAP) show potential, but PACAP
Area of Science:
- Neuroendocrinology
- Obesity Research
- Pharmacology
Background:
- Current anti-obesity pharmacologic tools are largely ineffective.
- Effective obesity treatments must enhance hypothalamic satiety sensitivity to leptin and antagonize Neuropeptide Y (NPY).
- Investigating peptide analogs like NPY-5 antagonists and various agonists is ongoing.
Purpose of the Study:
- To evaluate the potential roles of Glucagon-like peptide-1 (GLP-1) and Pituitary adenylate cyclase-activating polypeptide (PACAP) in obesity treatment.
- To explore GLP-1 and PACAP interactions within key hypothalamic nuclei involved in appetite regulation.
Main Methods:
- Examining GLP-1 receptor distribution in hypothalamic nuclei (ARC, PVN, VMN, SON) and its association with GLUT-2 and glucokinase.
- Investigating PACAP presence in hypothalamic areas (ARC, PVN, SCH) and its receptor's signaling pathways (cAMP, inositol triphosphate).
- Assessing the effects of GLP-1 and PACAP on food intake, insulin secretion, and neuronal activation (c-fos).
Main Results:
- GLP-1 receptors are located in key hypothalamic satiety centers, and GLP-1 reduces food intake and induces c-fos expression in the ARC.
- PACAP is present in relevant hypothalamic areas and may antagonize NPY-induced feeding and hyperinsulinemia.
- PACAP also activates irrelevant neuroendocrine, autonomic, and circadian functions, posing challenges for its therapeutic use.
Conclusions:
- GLP-1 shows promise as a therapeutic agent for obesity due to its effects on hypothalamic satiety centers.
- PACAP's broader neuroendocrine and autonomic effects make it a less suitable candidate for obesity treatment compared to GLP-1.
- Further research is needed to fully elucidate the therapeutic potential and limitations of these peptides in obesity management.
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