Differential Regional Distribution of Enterostatin, an Appetite Inhibiting Peptide, in the Brains of Zucker and Sprague-Dawley Rats

Abstract

Enterostatins are pentapeptides represented at the amino-terminus of procolipase molecule. Val-Pro-Asp-Pro-Arg or VPDPR is one such enterostatin. Pharmacologic studies suggest a role for VPDPR in appetite regulation and insulin secretion; however, due to the lack of a suitable assay method, the function of endogenous peptide has not been possible to discern until now. In the present investigation, we have shown the presence of a VPDPR-like immunoreactivity (VPDPR-LI) in the rat brain. On further characterization, brain VPDPR-LI was shown not to be due to APGPR, VPGPR, or VPDPR but to another peptide with an epitope similar to VPDPR. We have also examined the distribution of VPDPR-LI in different regions of the brains of Sprague-Dawley and Zucker rats. The results show (a) an uneven distribution of VPDPR-LI with the highest concentration in the striatum of both strains of rats, and (b) significantly lower levels of VPDPR-LI in all brain regions of Zucker compared to Sprague-Dawley rats.

Keywords:

• Enterostatin
• Appetite
• Fat intake