Meeting Abstract

P2.121  Sunday, Jan. 5 15:30  The Effects of Annetocin on the Isolated Crop-Gizzard of Lumbricus terrestris VU, CL*; KRAJNIAK, KG; Southern Illinois Univ. Edwardsville; Southern Illinois Univ. Edwardsville cvu@siue.edu

Numerous neurotransmitters and hormones can regulate the earthworm digestive tract. Previously, we showed that oxytocin and vasotocin, two members of the mammalian oxytocin/vasopressin family of peptides, modulated the isolated crop-gizzard of the earthworm, Lumbricus terrestris . This study examined the effects of annetocin, an oxytocin-related peptide, that was isolated from Eisenia foetida, on the isolated Lumbricus crop-gizzard. The crop-gizzard was placed in a tissue bath and mechanical recordings were recorded by a force transducer. The tissues were challenged by increasing concentrations of the peptide and the resulting changes in contraction rate and amplitude were used to create log-concentration response curves. Annetocin caused an increase in rate of contraction with a threshold of 10^-8 M and an increase in contraction amplitude at 10^-9 M. Compared to the other members of the peptide family annetocin had the highest efficacy in both contraction rate and amplitude, suggesting the Lumbricus receptor recognizes the earthworm sequence to a greater degree than the mammalian sequences. We are currently examining the effects of this peptide family on other regions of the digestive tract in L. terrestris .