scholarly journals Possible Enzymatic Mechanism Underlying Chemical Tolerance and Characteristics of Tolerant Population in Scapholeberis Kingi

Author(s):  
Makoto Ishimota ◽  
Mebuki Kodama ◽  
Naruto Tomiyama

Abstract To determine the potential effects of pesticides on aquatic organisms inhabiting a realistic environment, we explored the characteristics and mechanisms of chemical tolerance in Scapholeberis kingi. We established a chemical-tolerant population via continuous exposure to pirimicarb, an acetylcholinesterase (AChE) inhibitor, and examined the effects of pirimicarb concentration on the intrinsic growth rates (r) of tolerant cladocerans. We also explored the association between r and feeding rate and tested the involvement of antioxidant enzymes [peroxidase (PO) and superoxide dismutase] and AChE in pirimicarb sensitivity. S. kingi was continuously exposed to sublethal pirimicarb concentrations (0, 2.5, 5, and 10 µg/L) for 15 generations and changes (half maximal effective concentration at 48 h, 48 h-EC50) in chemical sensitivity were investigated. In the F14 generation, the sensitivity of the 10 µg/L group was three times lower than that of the control group, suggesting the acquisition of chemical tolerance. Moreover, r was significantly and negatively correlated with 48 h-EC50, suggesting a fitness cost for tolerance. Surprisingly, there was no significant correlation between r and feeding rate. Our generalized linear model indicated that elevated PO activity may be related to chemical tolerance. Therefore, oxidative stress regulation may be involved in the acquisition of chemical tolerance in cladocerans. These findings will help elucidate the characteristics and mechanisms of chemical tolerance in aquatic organisms inhabiting a realistic environment.

Jurnal MIPA ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 160
Author(s):  
Aprelia Martina Tomasoa ◽  
Deidy Azhari

Laju pertumbuhan dan tingkat reproduksi yang tinggi merupakan karakteristik unggul yang dimiliki ikan nila sebagai komoditi budidaya. Tingkat reproduksi yang tinggi menyebabkan terjadinya pematangan gonad sebelum mencapai ukuran produksi dimana hal tersebut dapat merugikan pembudidaya, karena saat ikan mengalami matang gonad energi hasil asimilasi pakan sebagain besar akan dialokasikan untuk perkembangan gonad dan menghambat pertumbuhan somatik. Pemanfaatan senyawa aktif dari bahan alami biji pepaya dapat menjadi solusi untuk meningkatkan pertumbuhan ikan yang dibudidayakan sekaligus menjaga keamanan pangan dan konsumen. Penelitian ini bertujuan untuk mengetahui pemanfaatan tepung biji pepaya terhadap respons pertumbuhan dan tingkat kelangsungan hidup ikan nila. Ikan nila diberi perlakuan dengan lima dosis tepung biji pepaya berbeda (0, 1, 3, 5 dan 7 g/kg pakan) secara oral berdasarkan feeding rate 5% dengan tiga ulangan selama 30 hari pemeliharaan. Hasil penelitian menunjukkan dosis 5 g/kg meningkatkan pertumbuhan bobot tubuh tertinggi sebesar 547 g dibandingkan kontrol sebesar 406 g. Sejalan dengan pertumbuhan bobot tubuh, dosis 5 g/kg menghasilkan tingkat kelangsungan hidup ikan nila sebesar 100% dibandingkan kontrol sebesar 66%. Dari hasil yang diperoleh dapat disimpulkan bahwa tepung biji pepaya dengan dosis 5 g/kg pakan dapat meningkatkan pertumbuhan dan tingkat kelangsungan hidup ikan nila selama 30 hariHigh growth rate and high reproductive cycle are some economical triats on nile tilapia. This is a setback for nile tilapia culture because when the fish reach gonad maturity before reach market size, all the energy demand will flow to reproduction and can cause stunt growth. The utilization of natural compound from papaya seeds can be a solution to enhance growth of farmed nile tilapia and for consumer and food safety. This research aim to know how papaya seed powder can enhance growth and survival rate of nile tilapia. This research conducted into five groups of 5 papaya seeds powder dosage (0, 1, 3, 5 and 7 g/kg) that feed orally to the treatment fishes. Result showed the fishes feed with 5 g/kg papaya seed experienced highest growth performance 547 g compare to control which is 406 g. Same as growth performance, survival rate shown that group feed with 5 g/kg papaya seed had 100% survival rate compare with control which is 66% during treatment periods. Base on this result, we can make conclusion that fish feed with 5 g/kg of papaya seed have a better growth performance and survival rate compare with control group for 30 days treatment periods


2018 ◽  
Vol 1 (1) ◽  
pp. 69-93 ◽  
Author(s):  
Lena Wimmer ◽  
Lisa von Stockhausen ◽  
Silja Bellingrath

AbstractRegulatory abilities such as self-regulation and stress regulation are key predictors of essential developmental outcomes, including intellectual and socioemotional milestones as well as academic achievement. Preadolescence has been proposed as a period that is crucial for training these abilities. The present pilot study investigated the effects of mindfulness training on preadolescents‘ regulatory abilities and school-related outcomes. A group of 34 fifth graders received either mindfulness training (experimental group), Marburg Concentration Training (alternative treatment group), or no treatment (passive control group) and were monitored over a four-month intervention period. Regulatory abilities were assessed first, with two self-report questionnaires that operationalized impulsivity and coping with stress, respectively. Second, physical stress regulation was examined on the basis of diurnal cortisol as well as salivary α-amylase (sAA) profiles. Finally, school-related outcomes were measured with a paperpencil based performance test of verbal memory. Results show that impulsivity increased in all groups over time, whereas there were no significant training effects on self-reported coping with stress. Both training groups showed more adaptive physiological stress regulation in terms of steeper diurnal cortisol slopes and marginally less pronounced sAA awakening responses, however, with respect to physiological measures, no data of the passive control group are available. With respect to school-related outcomes, the results indicate a slight superiority regarding verbal memory for the mindfulness training group compared to the Marburg Concentration Training group.


2018 ◽  
Vol 16 (1) ◽  
pp. 105-113 ◽  
Author(s):  
A Dey ◽  
K Ghosh ◽  
N Hazra

Growth and survival of Clarias batrachus juveniles (10-day old) fed probiotic Bacillus cereus (KR809412) encapsulated live feed (chironomid larvae) have been evaluated after differential exposure to the pathogenic Aeromonas hydrophila (MTCC 1739). Catfish juveniles were stocked at a density of 30 fish per tank in five experimental groups (T1-T5) along with a control group in triplicate and fed twice @ 5% of body weight day-1 for four weeks. Groups T1 and T2 were fed probiotic-encapsulated (PR) or pathogen-inoculated (PGN) live feed respectively, for initial three weeks. During this period groups T3 (PGN-PR-PR), T4 (PR-PGN-PR), and T5 (PR-PR-PGN) were differentially exposed to the pathogen. Live feed without probiotic and pathogen was offered to the control group throughout the experimental period and all other treatment groups (T1-T5) during the 4th week. Continuous exposure to probiotics in group T1 resulted in significantly higher (P<0.05) specific growth rate (SGR, % d-1) and survivability than other groups, whereas, pathogen exposed and probiotic deprived group (T2) noticed with the lowest SGR and the highest mortality. Among other treatment groups (T3, T4 and T5), group T4 resulted in improved SGR and survivability. The coefficient (r value) of 0.867 along with regression slope suggested a positive correlation (0.01 levels) between RNA: DNA and SGR. The study might suggest protective effects of probiotic B. cereus in pathogen exposed C. batrachus juveniles.SAARC J. Agri., 16(1): 105-113 (2018)


2009 ◽  
Vol 78 (3) ◽  
pp. 505-512 ◽  
Author(s):  
Jana Máchová ◽  
Miroslav Prokeš ◽  
Hana Kroupová ◽  
Zdeňka Svobodová ◽  
Stanislava Mácová ◽  
...  

Dimethyl sulphoxide (DMSO) is an important polar aprotic solvent, less toxic than other members of this class. Because of its excellent solvating power, DMSO is frequently used as solvent for chemical reactions involving salts, especially Finkelstein reactions and other nucleophilic substitutions. Furthermore, DMSO is used as auxiliary substance in toxicity tests on aquatic organisms, usually at concentrations of 0.2 and 0.5 ml l-1. The aim of the present study was to evaluate the effect of DMSO on early development, growth and mortality of early life stages in common carp. Tests were performed from fertilized egg to the end of the larval period with continuous exposure to DMSO at concentrations of 0.2, 0.5, 1.0 and 5.0 ml l-1. Mortality of embryos and larvae, intensity of development and growth, weight and occurrence of abnormalities were analyzed. DMSO exposure at all the tested concentrations did not result in any lethal effects or abnormalities compared to the control over the entire test period (29 days). Growth indicators were similar in DMSO treated (at concentrations of 0.2, 0.5 and 1.0 ml l-1) and control groups. However, mean body weight (35 ± 9 mg) of larvae exposed to the highest DMSO concentration (5 ml l-1) tested was significantly lower compared to the control (45 ± 14 mg).


2009 ◽  
Vol 87 (6) ◽  
pp. 455-459 ◽  
Author(s):  
George R. Thomas ◽  
Jonathan M. DiFabio ◽  
Tommaso Gori ◽  
David J.A. Jenkins ◽  
John D. Parker

Continuous exposure to nitroglycerin (GTN) results in development of tolerance and is associated with increased free radical production and abnormal endothelial function. Elevated plasma biomarkers of inflammation have been shown to be associated with endothelial dysfunction in most cardiovascular conditions. It remains unclear whether exposure to GTN is also associated with increased biomarkers of endothelial and vascular injury or vascular inflammation. In an investigator-blind study, a total of 28 healthy volunteers were randomized to continuous therapy with GTN (0.6 mg/h 24 h/day for 7 days) or no therapy. Venous blood was collected on day 0 and day 7. Plasma levels of markers such as asymmetric dimethyl-arginine (ADMA), human soluble P-selectin, interleukin-6, tumor necrosis factor-α, intercellular adhesion molecule-1, and oxidized low-density lipoproteins were measured. The levels of blood markers on day 0 were similar in the control and GTN-treated groups. After 7 days of GTN exposure, there were no significant changes in the different markers of vascular inflammation and injury either in the GTN or control group (all p > 0.5). The present study documents that prolonged continuous therapy with transdermal GTN therapy is not associated with changes in markers of vascular inflammation and injury.


1989 ◽  
Vol 48 (2) ◽  
pp. 393-397 ◽  
Author(s):  
R. Kassem ◽  
J. B. Owen ◽  
I. Fadel

ABSTRACTTwo experiments are described investigating the possibility of advancing puberty in Awassi ewe lambs kept under semi-arid conditions in mid Syria using 197 single ewe lambs in 1982 and 165 in 1984. In both years, the animals were allocated to three groups each given different levels of supplementation with a barley/chopped straw mixture to achieve different levels of pre-mating growth (high, medium and low). In 1984, the three groups were further subdivided into four subgroups each given continuous exposure to teaser rams from different ages. These were 175, 200 and 230 days of age and a control group not given continuous access to the ram. The results for the two experiments showed that a higher proportion of ewe lambs on the high and medium treatments showed oestrus in their first season (H = 88%, M = 72%, L = 41%; P < 0·01). The high level of nutrition also advanced the mean date of first oestrus in the high group by 22 and the age at conception by 16·5 days as compared with the low level.In the second experiment, no interaction between feeding level and presence of ram was observed and although there were no significant effects on occurrence of oestrus, continuous exposure to vasectomized rams from 175 days reduced mean age at first oestrus by 16 and age at conception by 19 days as compared with the unexposed controls.It is concluded that these practices have important implications for the efficient use of semi-arid range land by Awassi sheep on a semi-intensive system.


2021 ◽  
Author(s):  
Makoto Ishimota ◽  
Naruto Tomiyama

Abstract To ascertain the tolerance mechanisms of aquatic organisms to artificial chemicals, intergenerational sensitivity changes of Chironomus yoshimatsui to a carbamate pesticide (pirimicarb) and pharmaceutical chemical (diazepam) were investigated. The larvae (< 48-h-old) in each generation were exposed to both chemicals for 48 h and then the surviving chironomids were cultured until the fifth generation (F0–F4) without chemical addition. The 48-h 50% effective concentration (EC50) value of chironomids was determined for each generation. In the pirimicarb treatment group, the EC50 values significantly increased in F3 and F4, and those in the diazepam treatment group slightly increased. Catalase, Cytochrome P450 and hemoglobin (Hb) mRNA levels were monitored to see whether these were related to the trans-generational sensitivity. Although the generalized linear model results showed that the sensitivity to diazepam was slightly increased in the diazepam treatment, we could not find any mRNA levels related to sensitivity alteration. In contrast, the model approach showed that the chironomids exposed to pirimicarb trans-generationally became tolerant with increasing Hb mRNA levels. Therefore, they might decrease their oxidative chemical stress by modifying Hb gene transcription.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fawzy I. Magouz ◽  
Mahmoud F.I. Salem ◽  
Aliaa E.I. Emara ◽  
Mohamed M. Hassan ◽  
Mahmoud A.O. Dawood

Abstract The feasible strategies to keep up the growth and wellbeing of aquatic organisms by using beneficial dietary additives is highly recommended. Among these additives, β-glucan (BG) and mannanoligosaccharide (MOS) were examined on common carp performances in the current experiment. For 80 days, carps fed four diets with 0%, 1%, 2%, and 3% BG/MOS (1:1) and distributed in four groups (triplicates). Higher final weight and weight gain (P < 0.05) were detected in carps fed 1%, 2%, and 3% of BG/MOS than the control group. The feed conversion ratio showed lower values (P < 0.05) in carps-fed BG/MOS mixture at 2%, and 3% than 0% and 1% levels. The activities of amylase, lipase, and protease were higher in fish fed BG/MOS mixture than the control group. Interestingly, fish fed BG/MOS mixture had markedly increased villi length and width with branched villi integrity. Further, the count of goblet cells was increased (P < 0.05) in groups fed BG/MOS mixture than carps fed the basal diet. The hemoglobin and hematocrit levels and the counts of red and white blood cells were higher in carps fed BG/MOS mixture than the control with the highest counts in 3% level. Additionally, the blood total protein, globulin, and phagocytic activity were higher (P < 0.05) in groups received BG/MOS mixture at 3% than the control. The lysozyme had a higher value in 1% group than the control (P < 0.05). Therefore, using the mixture of BG/MOS at 2-3% is suggested for improving the growth rate, intestinal health, blood health, and immunity of common carp.


2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Baoxuan Lin ◽  
Xiquan Weng ◽  
Yu Chen ◽  
Yan Meng

Objective The purpose of this study was to explore the function of Lycium Barbarum juice on exercise stress regulation when male university students drank Lycium Barbarum juice during increasing resistance exercise, by observing the effects of oral Lycium Barbarum juice on the blood glucose, serum Adrenocorticotropic Hormone (ACTH), insulin and glucagon concentration. Methods 21 to 22, healthy, 28 male university students participated in the study. They were randomly divided into a control group (n=16)and an experimental group(n=12). All participants completed four-stage incremental load movement for a total of 32 days. The exercise intensity of four stages was 60% VO2max, 70% VO2max, 80% VO2max and 90% VO2max, respectively. Each stage was exercised every-other-day, 4 times per stage and 1 hour each time. During the exercise, each subject in the experimental group drank 100 ml of 100% Lycium Barbarum juice before going to bed every day. Before the experiment and the morning after the end of each phase, a participant’s elbow-venous blood was collected to separate the serum. In all serum substances, the concentrations of ACTH, insulin, glucagon were detected by ELISA system. Fasting blood glucose concentration was detected by a blood glucose meter (Kyoto GT-1640 glucose meter, Japan). SPSS 17.0 software was used for statistical analysis. Results 1) The serum ACTH concentration of the subjects continually increased with the progress of the incremental load exercise and reached the highest at the end of the fourth stage. Compared with the increase in the control group (P<0.05), the experimental group was more significant (P<0.01). 2) Compared with before the experiment, both control group and experimental group were no obvious changes of blood glucose concentration in the first and second stages, and the control group was significantly decreased in the third and fourth stages (P<0.05), while the experimental group was not (P>0.05). 3) During the increasing load exercise, the changes of insulin in serum of the participants were basically the same. The insulin level increased significantly at the end of the first stage and decreased successively at the end of the last three stages. At the end of the fourth stage, the serum insulin level of the control group decreased more significantly (P<0.05) than the experimental group (P>0.05). 4) The glucagon concentration in the control group continued to increase with the increase of the load. By contrast, the glucagon concentration in the experimental group gradually decreased at the end of the first stage and then increased at the end of the fourth stage. However, all of the increase and decrease are not statistically significant. Conclusions During increasing resistance exercise, drinking Lycium Barbarum juice can increase the ability of the body to regulate Adrenocorticotropic Hormone (ACTH), insulin and glucagon through the exercise stress regulation systems, the Hypothalamic-Pituitary-Adrenal Cortical Hormone system (HPA) and the Sympathetic-Adrenal Medullary system. It plays an important role in maintaining blood sugar levels during increasing resistance exercise and accelerating post-exercise function recovery after exercise.


2004 ◽  
Vol 18 (2) ◽  
pp. 105-109 ◽  
Author(s):  
Lara Cristina Picoli ◽  
Ii-Sei Watanabe ◽  
Ruberval Armando Lopes ◽  
Miguel Angel Sala ◽  
Fábio Picoli

Cadmium (Cd) present in the air, drinking water and food has the potential to affect the health of people, mainly those who live in highly industrialized regions. Cd affects placental function, may cross the placental barrier and directly modify fetal development. It is also excreted into milk. The body is particularly susceptible to Cd exposure during perinatal period. The effect on rat oral epithelium (floor of the mouth) after continuous exposure to drinking water containing low levels of Cd during lactation was studied. Female rats were supplied with ad libitum drinking water containing 300 mg/l of CdCl2 throughout the whole lactation period. Control animals received a similar volume of water without Cd. Lactating rats (21 day-old) were killed by lethal dose of anesthetic. The heads were retrieved, fixed in "alfac" solution (alcohol, acetic acid and formaldehyde) for 24 h, serially sectioned in frontal plane, at the level of the first molars. The 6 µm sections were then stained with hematoxylin and eosin. Nuclear epithelium parameters were estimated, as well as cytoplasm and cell volume, nucleus/cytoplasm ratio, numeric and surface densities, and epithelial thickness. Mean body weight was 34.86 g for the control group and 18.56 g for the Cd-treated group. Histologically, the floor of the mouth epithelium was thinner in the treated group, with smaller and more numerous cells. In this experiment, Cd induced epithelial hypotrophy, indicating a direct action in oral mucosa cells, besides retarded development of the pups.


Sign in / Sign up

Export Citation Format

Share Document