The effect of the antidepressant venlafaxine on gene expression of biotransformation enzymes in zebrafish (Danio rerio) embryos.

The effect of venlafaxine, a pharmaceutical commonly found in aquatic environment, was analyzed on non-target organism, Danio rerio (Hamilton, 1822). D. rerio embryos were treated by two different concentrations of venlafaxine: either concentration relevant in aquatic environment (0.3 µg/L) or concentration that was two orders of magnitude higher (30 µg/L) for the evaluation of dose-dependent effect. Time-dependent effect was rated at 24, 96, and 144 h post-fertilization (hpf). For gene expression, genes representing one of the phases of xenobiotic biotransformation (0 to III) were selected. The results of this study showed that the effect of venlafaxine on the zebrafish embryos is the most evident at hatching (96 hpf). At this time, the results showed a downregulation of gene expression in each phase of biotransformation and in both tested concentrations. In contrast, an upregulation of most of the genes was observed 144 hpf for both tested venlafaxine concentrations. The study shows that venlafaxine can affect the gene expression of biotransformation enzymes in D. rerio embryos even in the environmentally relevant concentration and thus disrupt the process of biotransformation. Moreover, the pxr regulation of genes seems to be disrupted after venlafaxine exposure in dose- and time-dependent manner.

Effects of antidepressants with different modes of action on early life stages of fish and amphibians.

Drugs are excreted from the human body as both original substances and as metabolites and enter aquatic environment through waste water. The aim of this study was to widen the current knowledge considering the effects of waterborne antidepressants with different modes of action-amitriptyline, venlafaxine, sertraline-on embryos of non-target aquatic biota-fish (represented by Danio rerio) and amphibians (represented by Xenopus tropicalis). The tested concentrations were 0.3; 3; 30; 300 and 3000 µg/L in case of amitriptyline and venlafaxine and 0.1; 1; 10; 100 and 1000 µg/L for sertraline. Test on zebrafish embryos was carried out until 144 h post fertilization, while test on Xenopus embryos was terminated after 48 h. Lethal and sublethal effects as well as swimming alterations were observed at higher tested concentrations that are not present in the environment. In contrast, mRNA expression of genes related to heart, eye, brain and bone development (nkx2.5, otx 2, bmp4 and pax 6) seems to be impacted also at environmentally relevant concentrations. In a wider context, this study reveals several indications on the ability of antidepressants to affect non target animals occupying environments which may be contaminated by such compounds.

Oxidative stress induced by fluoroquinolone enrofloxacin in zebrafish (Danio rerio) can be ameliorated after a prolonged exposure.

The purpose of our experiment was to evaluate the effect of enrofloxacin on biotransformation, oxidative stress and mRNA expression of related genes in fish as a non-target organisms. Zebrafish (Danio rerio) juveniles were treated with enrofloxacin at concentrations of 5, 10 and 500 µg/L for 14 days. A three-day-long test caused changes of catalytic activity of glutathione peroxidase and glutathione-S-transferase. Moreover, lipid peroxidation was observed at the highest concentration. No significant changes either in catalytic activity of antioxidant enzymes or elevated lipid peroxidation were observed from sampling day 7 on. mRNA expression of genes encoding antioxidant enzymes was also not affected by enrofloxacin after a 14-day exposure. This suggests the ability of D. rerio juveniles to adapt to enrofloxacin in a short time period. Moreover, enrofloxacin was not shown to affect collagen, cathepsin K, optic atrophy 1 and pyruvate kinase L/R mRNA expression in this study.

mRNA expression of antioxidant and biotransformation enzymes in zebrafish (Danio rerio) embryos after exposure to the tricyclic antidepressant amitriptyline.

Now-a-days, the occurrence of antidepressant residues in surface waters has become a major concern. Amitriptyline (AMI) has been described to treat depression and other disorders for decades. However, little is known about its effect on non-target organisms. The aim of this study was to assess the potential impact of AMI on the mRNA expression of antioxidant and detoxification enzymes during the early embryonic development of zebrafish (Danio rerio). Fertilized D. rerio embryos were exposed to AMI at concentrations of 300 ng/L and 30 µg/L and sampled 24, 48, 96, and 144 h post fertilization (hpf) to assess the mRNA expressions of cytochrome P450 1A1, glutathione-S-transferase, glutathione peroxidase, superoxide dismutase, and catalase. The time courses of the mRNA expressions of antioxidant and detoxification enzymes revealed characteristic changes during embryonic development causing generally transient changes post hatching; however, AMI did not cause any significant impact except in the case of CAT after 144 h, which was significantly upregulated by the AMI concentration of 30 µg/L. The results suggest that the antidepressant AMI causes only moderate to minor impacts on antioxidant and detoxification enzymes during early embryonic development of the non-target organism D. rerio and that CAT is the only biomarker affected by AMI.

Transport losses in finisher pigs: impact of transport distance and season of the year.

OBJECTIVE: The death of animals during transport for slaughter is a major factor indicating the level of welfare in transported animals. The aim of this study was to assess mortality related to the commercial transport of finisher pigs for slaughter in the Czech Republic. METHODS: The inspectors of the State Veterinary Administration of the Czech Republic recorded the numbers of finisher pigs transported to processing plants in the Czech Republic for slaughter and the mortality in these pigs in relation to transport in the period from 2009 to 2014. RESULTS: Our results show that the likelihood of death losses in transported pigs increases with increasing transport distance. The transport-related mortality ranged from 0.049% in pigs transported for distances below 50 km to 0.145% in pigs transported for distances exceeding 300 km. The impact of external air temperature on the transport-related mortality found in our study clearly shows that current transport practices fail to ensure the welfare of pigs transported under other than moderate weather. Particularly cold temperatures below -2°C were associated with increased death losses in winter transport. CONCLUSION: Despite a decreasing trend in the mortality of finisher pigs transported for slaughter in Europe, our study suggests that current transport conditions are not efficient at ensuring the welfare of pigs during transport for longer distances and the protection of pigs against the negative impact of extreme ambient temperatures. Further research should focus on developing practical guidelines to improve the welfare of pigs in transit accordingly.

The effects of chronic intermittent noise exposure on broiler chicken performance.

Effects of different noise levels (70 or 80 dB) that broilers were exposed to during the entire fattening period and also the effect of the timing of the first exposure to intermittent noise in the course of fattening (day 1 vs. day 7) were monitored. After 7 days of exposure to intermittent noise, experimental chickens already showed a significant decrease in live body weight in comparison with the control group. The difference between the group exposed to intermittent noise at 70 dB and the group exposed to 80 dB levels was not statistically significant, although the mean live body weight of broilers in the latter was lower during the entire fattening period. The chickens exposed to intermittent noise from day 1 of age showed lower mean live weight throughout the fattening period compared to chickens exposed to the same level of intermittent noise only from day 7 of age, although at the end of fattening the difference was statistically significant only in chickens exposed to the higher level of intermittent noise (80 dB).

Changes in selected biochemical indices resulting from various pre-sampling handling techniques in broilers.

BACKGROUND: Since it is not yet clear whether it is possible to satisfactorily avoid sampling-induced stress interference in poultry, more studies on the pattern of physiological response and detailed quantification of stress connected with the first few minutes of capture and pre-sampling handling in poultry are required. This study focused on detection of changes in the corticosterone level and concentrations of other selected biochemical parameters in broilers handled in two different manners during blood sampling (involving catching, carrying, restraint, and blood collection itself) that lasted for various time periods within the interval 30-180 seconds. METHODS: Stress effects of pre-sampling handling were studied in a group (n = 144) of unsexed ROSS 308 broiler chickens aged 42 d. Handling (catching, carrying, restraint, and blood sampling itself) was carried out in a gentle (caught, held and carried carefully in an upright position) or rough (caught by the leg, held and carried with lack of care in inverted position) manner and lasted for 30 s, 60 s, 90 s, 120 s, 150 s, and 180 s. Plasma corticosterone, albumin, glucose, cholesterol, lactate, triglycerides and total protein were measured in order to assess the stress-induced changes to these biochemical indices following handling in the first few minutes of capture. RESULTS: Pre-sampling handling in a rough manner resulted in considerably higher plasma concentrations of all biochemical indices monitored when compared with gentle handling. Concentrations of plasma corticosterone after 150 and 180 s of handling were considerably higher (P < 0.01) than concentrations after 30-120 s of handling regardless of handling technique. Concentrations of plasma lactate were also increased by prolonged handling duration. Handling for 90-180 seconds resulted in a highly significant elevation of lactate concentration in comparison with 30 s handling regardless of handling technique. Similarly to corticosterone concentrations, a strong positive correlation was found between plasma lactate and duration of pre-sampling handling. Other biochemical indices monitored did not show any correlation pattern in connection with duration of pre-sampling handling. CONCLUSIONS: These results indicate that the pre-sampling procedure may be a considerably stressful procedure for broilers, particularly when carried out with lack of care and exceeding 120 seconds.

Responses of peripheral blood leukocytes to chronic intermittent noise exposure in broilers.

The purpose of the study was to specify full leukocytic responses in broilers to chronic intermittent noise exposure at two different levels (70 and 80 dB) and to assess the effect of the timing of the beginning of exposure to intermittent noise (from day 1 or day 7 of fattening). Noise treatment of 80 dB resulted in a significant (P < 0.05) elevation of heterophil to lymphocyte ratio (HLR) indicating a stress response of the broilers to the noise stimulus at the level of 80 dB in the course of fattening, in contrast to the 70 dB noise that did not cause any significant changes in HLR when compared to the control without noise treatment. Noise treatment of both 70 and 80 dB intensities also resulted in a significant elevation of basophil granulocytes. We found a different leukocytic response in broilers exposed to chronic intermittent noise from the first day of fattening in comparison to broilers exposed to this noise stimulus from the seventh day. There was a significantly smaller total number of leukocytes (P < 0.01) and significantly smaller differential counts of heterophils (P < 0.01), lymphocytes (P < 0.01) and basophils (P < 0.05) in broilers treated with noise (both 70 dB and 80 dB) from day 7 (group Day7) than in broilers treated with noise from day 1 (group Day 1). Differential counts of eosinophils and monocytes were not affected by the time of exposure to intermittent noise in this study.

Effects of different crating periods on selected biochemical indices in broiler chickens.

Effects of different crating periods on selected biochemical indices were monitored in a group of unsexed ROSS 308 broiler chickens aged 42 days. 120 randomly selected chickens were weighted and placed in 15 heavy duty plastic crates with reduction in floor space approx. 160 cm2/kg of body weight of broilers (average body weight was 2.75 kg). Five crates were kept for 4 hours (Group 4h), another five crates for 8 hours (Group 8 h) and another five crates for 12 hours (Group 12h). After tested periods of crating the broilers were released and blood samples were withdrawn from Vena bosilico in 24 randomly selected birds from each group (Groups 4 h, 8 h, 12 h respectively) and also in other 24 randomly selected non-crated control birds. The results of our experiment proved that duration of crating significantly influenced the stress response in broiler chickens. The duration of crating period was positively correlated with the plasma corticosterone level and negatively correlated with the lactate dehydrogenase, cholesterol, triglycerides, glucose and lactate levels in the blood of broiler chickens.

Effects of reduction in floor space during crating on haematological indices in broilers.

In the perspective of animal protection and welfare, the most common and potentially the most frightening events encountered by the domestic fowl are procedures connected with transport. This study provides an evidence that reduction in floor space during crating, which is approximately 10% above requirements given to EEC Directives (accompanied with mixed social and heat stress due to high animal density), induces markedly elevated stress in broilers which is manifested by changes in haematological indices. The experiment was performed on ROSS 308 broilers (total number 70, mean body weight 3.05 kg). At 42 days of age, the broilers were crated for 2-hours either with reduction in floor space to 115 cm2/kg (S115) or 105 cm2/kg (S105) of body weight. The total erythrocyte and leukocyte count, haematocrit, haemoglobin, MCV (mean cell value), MCH (mean cell haemoglobin) and MCHC (mean cell haemoglobin concentration) values were monitored and differential leukocyte count was assessed 20 h following crating. When compared with uncrated control, S105 broilers exhibited highly significant increase in haemoglobin level, MCH and MCHC values, significant increase in MCV values and significant decrease in total erythrocyte count. S115 broilers did not manifest any significant changes in haematological parameters compared with control. When compared with S115 broilers, S105 broilers manifested significantly elevated haemoglobin level and MCV values, highly significantly elevated MCH and MCHC values and depressed erythrocyte count. It follows from results that the reduction in floor space to 115 cm2/kg for 2 hours did not induce any significant changes in both total and differential leukocyte counts in blood of broilers when compared with control chickens. However, reduction in floor space to 105 cm2/kg resulted in highly significant increase in heterophil counts and subsequently also HLR (heterophil/lymphocyte ratio) was significantly elevated. When compared S105 and S115 broilers, mean values of heterophil counts and HLR ratio were higher due to reduction in floor space to 105 cm2/kg. The differences, however, were not statistically significant.