SUBUNIT-B OF CHOLERA-TOXIN LABELS INTERSTITIAL-CELLS OF CAJAL IN THE GUT OF RAT AND MOUSE

Cholera toxin subunit b was found in vivo and in vitro to label inters titial cells of Cajal in the intestine of rat and mouse. Cholera toxin -labelled interstitial cells were present in the subserosa, the myente ric plexus and the deep muscular plexus of mouse small intestine, and the deep muscular plexus only of the rat small intestine. In the large intestine of the mouse, interstitial cells were present in the subser osa and in a plexus associated with the inner surface of the circular muscle, while in the rat they were only present in the latter location . Macrophages, which were present in many of the same locations as int erstitial cells, were also labelled by cholera toxin but could be dist inguished from interstitial cells by their ability to take-up fluoresc ein isothiocyanate-labelled dextran. Labelling with subunit b of chole ra toxin is a simple way of labelling interstitial cells of Cajal and which is compatible with a range of physiological and histological pro cedures.