Meeting Abstract

P2.169  Saturday, Jan. 5  The Effects of APKQYVRFamide on the Isolated Intestine of the Earthworm Lumbricus terrestris. MCCULLOUGH, K.A.*; KRAJNIAK, K.G.; Southern Illinois University Edwardsville; Southern Illinois University Edwardsville kmccull@siue.edu

The digestive tract of the earthworm Lumbricus terrestris responds to a variety of neurotransmitters including FMRFamide and its related peptides (FaRPs). Recently we identified the first earthworm FaRP, APKQYVRFamide, from the genes of Lumbricus rubellus. The goal of this project was to examine the effects of this peptide on the intestine of L. terrestris. The intestine was removed and placed into a bath filled with worm saline. All movements of the intestine were recorded with a Grass force transducer and were displayed on a computer using iWorx Labscribe 2 software. Increasing concentrations of peptide were added to the bath and adequate time was allowed for each to take effect. The resulting changes in contractions were used to create log-concentration response curves. APKQYVRFamide caused a concentration dependent increase in contraction rate with a threshold of 10^-9 M. These results suggest that APKQYVRFamide may play a role in controlling the motility of the earthworm intestine. We are currently examining the effects of other structurally related peptides to characterize the intestinal receptor.