Activity of selected hydrolytic enzymes from leeches (Clitellata: Hirudinida) with different feeding strategies

Abstract

Hydrolase activities of extracts from different parts of the bodies of parasitic (Theromyzon tessulatum, Piscicola geometra) and predatory (Erpobdella octoculata, Glossiphonia complanata) leeches were examined. The highest activity was detected in the extracts from sections containing the intestine. Hydrolase activities in the crop and intestine of parasitic leeches were higher than in predatory leeches. The high activity of most of hydrolases in those segments may indicate the intensity of digestion and absorption processes in leeches. A lack of trypsin activity and low chymotrypsin activity are likely to result from the presence of inhibitors of these enzymes. The high activity of the majority of the analyzed hydrolases in extracts derived from the head segment of predatory leeches enables, through digestion of tissues, their easy access to physiological fluids of a host. In turn, in extracts from the head segment of predatory leeches, only four hydrolases were shown to be active. Lipase activity was not found in any of the samples, while α-galactosidase activity was found only in extracts from the head segment of T. tessulatum and P. geometra. Trypsin activity was detected in the extract from the intestine contents of H. sanguisuga and in the extract from the head segment of P. geometra. The results demonstrate the presence of majority of hydrolases occurring in other animals in the alimentary tract of leeches. The study also shows that the crop of leeches is not only a food reservoir, but also the site where digestion and absorption processes take place.

The activity of hydrolytic enzymes in the digestive system of Acanthobdellida, Branchiobdellida and Hirudinida (Annelida, Clitellata) – considerations on similarity and phylogeny

“…These enzymes are involved in the digestion of numerous nourishments. Our study revealed that the number of active enzymes in the crop of leeches that parasitize fish and predatory leeches is similar (17 to 18 enzymes), as reported by Dziekońska et al (2009). Moreover, we observed a very low level or absence of trypsin and α-chymotrypsin activity in the crop of all the leeches analyzed during our study.…”

“…glucose) are absorbed in the crop of P. geometra. Moreover, enzymatic (Dziekońska et al 2009) and ultrastructural studies (Rost-Roszkowska et al 2012) showed that digestion and absorption occur in the crop of these leeches. This statement was confirmed in our study as in the crop of the analyzed species (except B. astaci) the activity of acid and alkaline phosphatases was detected.…”

“…To eliminate bacteria and fungi, each collected specimen was kept for two days in an aqueous solution of antibiotics and fungicides (penicillin 100 U ml −1 , streptomycin 100 μl ml −1 , nystatin 100 U ml −1 ) (Dziekońska et al 2009). Then, specimens were frozen at −20°C in vials with physiological saline.…”

“…Generally, in our study the enzyme activities in the anterior part of the digestive system in parasitic leeches appeared to be lower than in predators (Figure 1). According to Dziekońska et al (2009), enzymes synthesized in the anterior region of the digestive system in predatory leeches feeding on large invertebrates are responsible for the beginning of digestion. Our study confirmed this statement, because as many as 16 to 19 enzymes have been found to be active in the pharynx of predatory leeches.…”

European Medicinal Leeches—New Roles in Modern Medicine

“…In most parasitic leeches the host blood is stored in the crop, while food digestion and the absorption of nutrients occur predominantly in the intestine. It can be assumed that medicinal leech enzymes (e.g., endopeptidases, aminopeptidases, phosphatases) promote digestion processes [14].…”