THE DIGESTIVE SYSTEM OF THE HOLOTHURIAN, CUCUMARIA ELONGATA. II. DISTRIBUTION OF THE DIGESTIVE ENZYMES

Open Access
Publisher Website
Google Scholar
Abstract
The different gut regions of C. elongata were tested for the presence of proteases, carbohydrases, and lipases. An endopeptidase of a trypsin-like nature and several exopeptidases were detected, and each showed maximum activity in the intestine. Cellulase and lactase were not detected, yet maltase and invertase were found in all regions of the gut and had maximum activity in the constriction and intestine I. Amylase was found only in the constriction and intestine I. A strong esterase and a weaker ''esterase-lipase'' were detected with practically uniform distribution throughout the gut. From the distribution of digestive enzymes and the results of previous histological and histochemical studies it is concluded that digestive enzymes are secreted by cells bordering the gut lumen.