Abstract
The aim of this study was to investigate if amylin's anorectic effect depends on diet composition and on the length of exposure to high caloric diets. Our investigations resulted in the following findings and conclusions. First study Findings: After three weeks voluntary Ensure® overfeeding, obese rats showed a significant anorectic response after central acute (5pmol) or chronic (2pmol/h) amylin. In addition, amylin-infused rats lost significantly more body weight than the control saline rats. Conclusion: Long-term access to Ensure® does not cause insensitivity to central amylin in obese rats. Second study Findings: After three days of voluntary Ensure® feeding, amylin injection (acute, central: 5pmol or peripheral: 5µg/kg), did not lower energy intake in rats that were still provided with access to Ensure®. However, amylin insensitivity was reversed by increasing the central dose to 10 or 100pmol, or by switching rats back to chow for three days. At that point, amylin-injected rats showed a significant decrease in energy intake similar to controls.Conclusion: Short-term Ensure® exposure causes amylin insensitivity, which is dose-dependent and reversible. Third study Findings: After three days of chow, high fat or Ensure® neutral access, amylin-injected rats (acute, central: 5pmol) ingested significantly less. Rats with access to Ensure® cacao for three days did not lower their intake after amylin.Conclusion: Amylin insensitivity after exposure to Ensure® seems to be more dependent on the palatable flavor, than diet composition.
Munz, Manuela