In vitro evidence that rabbit distal colonic muscularis mucosae has a Clostridium difficile toxin A receptor.

In the rabbit ileum Clostridium difficile toxin A causes inflammation and mucosal damage via a specific glycoprotein receptor that contains alpha-D-galactose. In rabbit colon toxin A also causes inflammation, and this is associated with increased myoelectric activity and eicosanoid production. The present in vitro study was undertaken to determine if a toxin A receptor on one or more layers of colonic smooth muscle could mediate the motor effects of this agent.

Diminished Clostridium difficile toxin A sensitivity in newborn rabbit ileum is associated with decreased toxin A receptor.

Human infants are relatively resistant to Clostridium difficile-associated diarrhea and colitis compared to adults. In that toxin A is the major cause of intestinal damage with this organism, we compared toxin A receptor binding and biological effects in newborn vs adult rabbit ileum. Purified toxin A (M(r) 308 kD) was labeled with tritium or biotin with full retention of biologic activity.

Characterization of rabbit ileal receptors for Clostridium difficile toxin A. Evidence for a receptor-coupled G protein.

The purpose of this study was to characterize the surface receptor for toxin A, the enterotoxin from Clostridium difficile, on rabbit intestinal brush borders (BB) and on rat basophilic leukemia (RBL) cells. Purified toxin A was radiolabeled using a modified Bolton-Hunter method to sp act 2 microCi/micrograms, with retention of full biologic activity. 3H-Toxin A bound specifically to a single class of receptors on rabbit BB and on RBL cells with dissociation constants of 5.