alpha-chymotrypsin and Fish-Diseases

A study was carried out to appraisal the function of methionine on intestinal digestion and the health of grass carp (Ctenopharyngodon idella) fry (initial weight 0.36 ± 0.01 g). The fry were fed graded dietary methionine levels (0.33%-1.20% dry matter) in 18 recirculatory tanks (180 L). After an 8-week breeding experiment, the results revealed that 0.71%-1.20% dietary methionine levels markedly upregulated the mRNA levels of intestinal digestion including trypsin, amylase, chymotrypsin and AKP, and 0.71%-0.87% dietary methionine level significantly increased intestinal trypsin activities compared with the 0.33% dietary methionine level. For inflammation, 0.71%-1.20% dietary methionine levels downregulated the mRNA levels of NF-κBp65, IL-1β, IL-6, IL-8, IL-15 and IL-17D, whereas upregulated the mRNA levels of anti-inflammatory cytokines, including IL-4/13B, IL-10 and IL-11. In terms of antioxidants, although dietary methionine levels had no significant effect on the expression of most core genes of the Nrf2/ARE signaling pathway, such as Nrf2, Keap 1, GPx4, CAT, Cu/Zn-SOD. Furthermore, dietary methionine levels had no significant effect on the expression of p38MAPK, IL-12p35, TGF-β2 and IL-4/13A. 0.71%-1.20% dietary methionine levels still increased the mRNA levels of GPx1α, GSTR and GSTP1. Furthermore, higher intestinal catalase activity and glutathione contents were also observed in fry fed 0.71%-1.20% diets. In summary, 0.71%-1.20% dietary methionine levels played a positive role in improving the intestinal digestion capacity of digestion, anti-inflammatory reaction and oxidation resistance of grass carp fry. This study provided a theoretical basis for improving the survival rate and growth of grass carp fry.

Topics: Aeromonas hydrophila; Amylases; Animal Feed; Animals; Carps; Catalase; Chymotrypsin; Dietary Supplements; Digestion; Fish Diseases; Fish Proteins; Glutathione; Inflammation; Interleukin-10; Interleukin-11; Interleukin-12 Subunit p35; Interleukin-15; Interleukin-27; Interleukin-4; Interleukin-6; Interleukin-8; Methionine; NF-E2-Related Factor 2; RNA, Messenger; Superoxide Dismutase; Transforming Growth Factor beta2; Trypsin

The mechanisms enabling fish tapeworms to avoid proteolytic attacks by digestive enzymes of their fish host have been studied in less detail compared with mammalian cestodes. This study aimed to assess the inhibitory ability towards trypsin and chymotrypsin in Eubothrium rugosum, an intestinal parasite of burbot Lota lota, and establish its localization in the tapeworm. To this end, the worms were treated with Triton X-100 followed by differential centrifugation to isolate the tegumental brush border membrane. The protease inhibitory abilities of the worms were mostly determined by their excretory/secretory products released into the incubation medium. These inhibitory abilities proved to be linked mainly with the brush border fractions. Notably, the per cent inhibition of both studied digestive enzymes (trypsin and chymotrypsin) hardly depended on the duration of the parasite exposure in the incubation medium, probably due to intermittent glycocalyx renewal. Improved knowledge on functions of the excretory/secretory proteins produced by fish tapeworms may contribute to a better understanding of host-parasite relations and development of new approaches to the treatment and prevention of diseases caused by pathogenic helminths.

Topics: Animals; Cestoda; Cestode Infections; Chymotrypsin; Fish Diseases; Fishes; Gadiformes; Host-Parasite Interactions; Protease Inhibitors; Trypsin Inhibitors

Topics: Animals; Chymotrypsin; Fish Diseases; Genetic Therapy; Myxobolus; Oncorhynchus mykiss; Parasitic Diseases, Animal; RNA Interference; RNA, Small Interfering

1. The pancreatic digestive enzyme activities of trypsin and chymotrypsin were assessed in vitro and were found to correlate well with the histological changes characteristic of pancreas disease (PD) in farmed Atlantic salmon (Salmo salar). 2. Pancreatic enzyme activity was assessed in vivo using the chymotrypsin specific substrate N-benzoyl-L-tyrosyl-p-aminobenzoic acid. In all cases, significantly less p-aminobenzoic acid was excreted by fish later found to be suffering from PD. 3. It is concluded that the in vitro digestive enzyme assay was effective in diagnosing PD with the in vivo method, indicating further promise for assessing exocrine pancreatic function.

Topics: Animals; Chymotrypsin; Fish Diseases; Pancreatic Diseases; Salmon; Trypsin

Binding of 125I-labelled types I and IV collagen, fibronectin and laminin to Aeromonas cells is a common characteristic among Aeromonas strains isolated from diseased fish and human infections. The proportion of Aeromonas strains which bind to the various proteins were significantly greater for A. hydrophila than for A. sobria or A. caviae. The binding property was specific since it was inhibited by unlabelled homologous proteins. Bacterial cells incubated with proteolytic enzymes lose the ability of binding to 125I-labelled collagen type I and IV, fibronectin, laminin and vitronectin. A bacterial cell surface protein extract, containing active receptors competes with intact cells for 125I-extracellular matrix protein binding. Culture conditions greatly influence the expression of A. hydrophila cell surface binding structures for extracellular matrix proteins. The presence of calcium ions in the growth medium seems to be an important enhancer of the expression of extracellular matrix protein cell surface receptors.

Topics: Aeromonas; Animals; Bacterial Infections; Bacterial Outer Membrane Proteins; Binding, Competitive; Calcium; Chymotrypsin; Collagen; Extracellular Matrix Proteins; Fibronectins; Fish Diseases; Fishes; Humans; Laminin; Radioligand Assay