Faculty Collaboration Database

Hymenolepis diminuta fractions but not previous tapeworm infection stimulate intestinal myoelectric alterations in vivo in the rat. J Parasitol 1998 Aug;84(4):673-80

Date

08/26/1998

Pubmed ID

9714192

DOI

10.2307/3284568

Scopus ID

2-s2.0-0031818277 (requires institutional sign-in at Scopus site)   13 Citations

Abstract

Infection of rats with the enteric, lumen-dwelling tapeworm Hymenolepis diminuta causes electric changes in host intestinal smooth muscle and decreased luminal transit. The mechanisms that stimulate host intestinal alterations during this nontissue invasive infection may include the tapeworm's biomass, its diurnal migratory behavior, a host immune-mediated response, or direct parasite stimulation of host motor activity. In vivo intestinal myoelectric activity was monitored to evaluate the following: (1) that reinfection with H. diminuta is influenced by host immune regulation and (2) that administration of tapeworm fractions to never-before-infected rats initiates an alteration of enteric smooth muscle activity. To address the first hypothesis, we determined that altered intestinal myoelectric activity patterns were no different and did not occur earlier in a second infection with H. diminuta than in a primary infection. The lack of either a change in myoelectric pattern or an earlier onset of intestinal myoelectric changes indicates that tapeworm-induced myoelectric activity is not anamnestically stimulated by host immunomodulatory mechanisms. Consistent with the second hypothesis, administration of either H. diminuta carcass homogenate or tegument-enriched fractions directly into the intestinal lumen of tapeworm-naive rats initiated myoelectric patterns previously characteristic of chronic H. diminuta infection. Additionally, the appearance of characteristic nonmigrating myoelectric patterns in uninfected rats administered tapeworm fractions indicates that a substance from H. diminuta acts as the triggering signal molecule for intestinal myoelectric alterations. These findings also indicate that neither the tapeworm's biomass nor its diurnal movement is required for initiation of H. diminuta-altered myoelectric patterns. We have shown that H. diminuta possess a signal molecule(s) that alters host enteric electric activity, and we suggest that these alterations may play an important role in the symbiotic rat-tapeworm interrelationship.

Author List

Dwinell MB, Bass P, Oaks JA

Author

Michael B. Dwinell PhD Director, Professor in the Microbiology and Immunology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Action Potentials
Animals
Electrodes, Implanted
Electromyography
Gastrointestinal Motility
Host-Parasite Interactions
Hymenolepiasis
Hymenolepis
Immunologic Memory
Intestinal Diseases, Parasitic
Intestine, Small
Male
Muscle, Smooth
Random Allocation
Rats
Rats, Sprague-Dawley
Recurrence
Tenebrio