I. L. Golovanova

In vitro effects of cadmium and DDVP (dichlorvos) on intestinal carbohydrase and protease activities in freshwater teleosts.

In vitro effects of cadmium (0.5-50 mg/l) and DDVP (0.2-100 mg/l) on the total amylolytic, sucrase and protease activities of intestinal mucosa have been studied for the first time in 11 freshwater teleosts. Total amylolytic activity in burbot, crucian carp and common carp, sucrase activity in blue bream and total proteolytic activity in burbot and pike were significantly decreased by cadmium at 50 mg/l. DDVP (at 0.2 mg/l) caused a significant decrease in total proteolytic activity in pike but had no effect on either protease or carbohydrase activities in other fish species.

Effects of cadmium, naphthalene, and DDVP on gut carbohydrases activity in bream (Abramis brama L. ) and Mozambique tilapia (Oreochromis mossambicus Peters)

Previous research has shown that sublethal concentrations of cadmium, naphthalene and dichlorvos (DDVP) decreased growth rates in bream and Mozambique tilapia. One of the factors known to affect fish growth is the activity of gut digestive enzymes such as of lipases, proteases, carbohydrases. We assumed that toxicant-induced inhibition of the digestive enzyme activity and, consequently, the impaired digestion of food may contribute to the reduction of growth in fish exposed to toxicants. However, the influence of toxicants on digestive enzyme activities is poorly studied. The contribution of toxicant-induced changes of digestive enzymes activity to growth rate retardation in exposed fish remains unknown. The goal of this study was to examine the influence of an organophosphorus insecticide DDVP, a polyaromatic hydrocarbon naphthalene, and a metal cadmium on fish gut carbohydrase (CH) activity. 14 refs., 2 tabs.

Effects of Organic Pollutants on Fish Digestive Enzymes: A Review

A brief overview of data on the effects of organic pollutants of different chemical natures (organochlorine, organophosphorous and organotin compounds, naphthalene, formalin, nitrosoguanidine, glyphosate, and metylmercury) on the activity of fish enzymes hydrolyzing basic food components is given. It is shown that the xenobiotics listed above have different effects on fish digestive enzymes. The directions of toxicant-induced changes may differ depending on the fish species, type of hydrolyzed substratum, diapason of toxicant concentrations, and experimental conditions.

The effect of organic toxicants on sensitivity of intestinal glycosidases to Cu and Zn in juvenile roach

The chronic effect (duration of exposure 218 days) of polychlorinated biphenyls (PCBs) and the prolonged effect of the short-term action of chlorophos or of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) during embryogenesis upon the sensitivity of intestinal glycosidases to Cu and Zn was studied in roach (Rutilus rutilus (L.) underyearlings. The Cu+2 and Zn+2 ions at concentrations ranging from 0.1 to 25 mg/L in vitro cause a 10–77% decrease in amylolytic activity in the intestinal mucosa of control roach. An elevated level of PCBs (50.8 ng/g wet weight of food and 426 ng/g dry weight of ground) increased the sensitivity of glycosidases to Cu and Zn. The embryotoxic action of chlorophos at concentrations of 1 × 10−6−1 × 10−2 mg/L in most cases increased the inhibitory effect of Cu but decreased that of Zn. As a rule, MNNG (3 × 10−7−3 × 10−1 mg/L) reduced the glycosidase sensitivity to the effect of metal ions. The magnitude and direction of the effect depend on the nature and concentration of toxicants.

Impact of polychlorinated biphenyls on the activity of intestinal proteinases and carbohydrases in juvenile roach Rutilus rutilus (L.)

The chronic effects that polychlorinated biphenyls (PCBs) have on the activities of proteinases and carbohydrates in intestinal mucosa and chyme in juvenile roach Rutilus rutilus (L.) have been studied for the first time. Upon consuming food with PCB 50.8 ng/g wet weight for 218 days, the exposition of fingerlings in aquariums with dirt bottoms (contents PCB 425.6 ng/g dry weight) reduces the proteolytic activity of mucosa to a greater degree than amylolytic activity; the activity of sucrase changes in different directions. In 2-year-old fish receiving PCB only with food (50.8 ng/g wet weight bottom), proteolytic and amylolytic activities of the mucosa are reduced 18 and 35% in comparison with the control (52 days); the sucrose activity is reduced 13% (52 days) and 22% (169 days). In most cases the relation of amylolytic activity to proteolytic activity in fish of the experimental groups is less than in the control. The enzyme activities in chyme change in different directions, depending on the terms and conditions of the experiment.

Effect of magnetic storm on the sensitivity of juvenile roach intestinal glycosidase to heavy metals (Cu, Zn) and the herbicide roundup

The effect of a magnetic storm (frequency range of 0–5 Hz) on the activity and sensitivity of underyearling intestinal glycosidase (maltase and amylolytic activity) to heavy metal ions (Cu2+ and Zn2+, concentrations of 0.1–25 mg/L) and the herbicide Roundup (0.1–50 µg/L) have been studied in vitro during early the embryogenesis of roach Rutilus rutilus (L.). The impact of the magnetic storm on roach embryos 48–72 h post fertilization increases the sensitivity of digestive glycosidases (except for maltase in the presence of Cu) to Cu, Zn, and Roundup.

Effect of the herbicide Roundup on the activity of Glycosidases of invertebrates and juvenile fish

The effects of in vitro exposure to the herbicide Roundup at concentrations of 0.1–50 μg/L on the activity of maltase and sucrase and the total amylolytic activity in the organism of invertebrates and fish fry have been investigated. Glycosidases in invertebrates are less sensitive to the herbicide than those in juvenile fish. Roundup has a greater inhibitory effect on glycosidase activity in the tissues of actual prey (roach recovered from pike stomach) than in potential prey (roach captured in the pond). The magnitude and direction of the effects depend on the animal species and the concentration of the toxicant.

Effects of heavy metals (Cu and Zn) on digestive glycosidases in benthivorous fish of areas of Rybinsk Reservoir differing in anthropogenic loads

The separate and combined in vitro effects of heavy metal ions (Cu and Zn) at concentrations of 0.1–25 mg/L on the activities of maltase, sucrase, and amylolytic activity in the intestines of bream and roach caught in areas of the Rybinsk Reservoir differing in anthropogenic loads have been studied. In fish from the polluted Sheksninskii Reach, membrane maltase and sucrase enzymes are less sensitive to the effects of Cu and Zn ions than in fish from the relatively clean Volzhskii Reach. On the other hand, starch-hydrolyzing enzymes were more sensitive to the effects of the metals under study in bream from a polluted area, which was especially evident in summer. The combined effect of Cu and Zn ions (1: 1) in most cases weakens the separate effects of these metals on the activities of hydrolases (except for amylolytic activity) in the studied fish.

Effects of Roundup Herbicide and Increase in Water Temperature on the Parameters of Peripheral Blood Cells in Amur Sleeper Perccottus glenii Dybowski

The separate and combined effects of chronic 30-day exposure to the herbicide Roundup in a sublethal concentration of 2 μg/L and an increase in water temperature at a rate of 8°C/h on the parameters of red and white blood in juveniles of Amur sleeper Perccottus glenii Dybowski have been studied. The ratio of mature and immature erythrocytes in the peripheral blood do not change under the influence of the studied factors. An increase in temperature after chronic exposure to Roundup leads to a decrease in red blood cell sizes and increase in the share of abnormal cells. Exposure to the herbicide and the rise in water temperature have the opposite effect on the number of amitosis in erythrocytes and the ratio of leucocyte cells; an antagonistic effect is identified under the combined action of the factors. Changes in white blood correspond to a nonspecific stress response; changes in red blood indicate a reduction in compensatory responses to hypoxia.

Influence of hypomagnetic conditions on the activities of glycosidases and kinetic characteristics of carbohydrate hydrolysis in juvenile roach, Rutilus rutilus

The study on remote consequences of hypomagnetic conditions during roach Rutilus rutilus embryogenesis (at the stages of embryo and prelarva) revealed multidirectional changes in body length/weight, activities of glycosidases (maltase, sucrase, and amylolytic activity), and kinetic characteristics of carbohydrates hydrolysis in the intestine of the yearlings. The exposure of embryos to hypomagnetic conditions leads to the increase in body length and weight in the yearlings; the exposure of prelarvae leads to the decrease in these parameters. The impact of hypomagnetic conditions at the stage of prelarva results in most pronounced changes in the physiological and biochemical parameters in the yearlings. Decline in the Michaelis constant values, reflecting affinity of an enzyme to substrate, may be considered as an adaptive response of the fish digestive system to the lack of magnetic field during embryogenesis.