ECOTOXICOLOGIA TERRESTRE PDF
Palavras-chave: Ecotoxicologia, testes ecotoxicológicos, toxicidade aguda, toxicidade crônica, biomonitora e comunidades, animais ou vegetais, terrestres ou. Ecotoxicología y Daño Testicular. de las especies biocentinelas y su importancia para el monitoreo de la evolución de ecosistemas acuáticos y/o terrestres. Many translated example sentences containing “ecotoxicologia” – English- Portuguese dictionary and search engine for English translations.
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This review briefly considers the testicular damage elicited by environmental chemical pollution. It includes a short comment on environmental toxicology as an introduction to environmental chemical pollution, highlighting the importance of this current field of study and its impact on male reproductive health. Furthermore an experimental animal model addressing the effect of organophosphorated agropesticides as a testicular toxicant is presented.
Moreover two relevant chemical contaminants and their effect on the testis, such as the classical case of lead and the rarely reported case of Boron on spermatogenesis, are considered. Environmental chemical pollution-testicular damage. Environmental toxicology studies the effect of environmental toxicants on the health of all organisms and on the different compartments of the environment. Its concern involves the fact that human survival depends on the preservation of other animal and plant species and on the environmental resources such as clean air, food and water, which are menaced mostly by anthropogenic chemicals that alter living organisms and ecological processes.
Therefore, ecotoxicology deals with two orientations: Chemical pollution and testicular function has been the subject of great concern in the last decades; so much so, that ina classical four volume book, “The Testis” was published.
Volume III has two chapters chapter 10 and 11 devoted respectively to the effect of cadmium on the testis and other mineral elements and chemical agents affecting testicular function and male fertility. A short review on specific chemical pollution such as agropesticides was recently published by our group.
In recent years, there has been growing concern on the deleterious effects that many chemicals may have on male reproduction. Globally, there are Our interest is on the male reproductive factor since most of these substances are testicular toxicants, present as occupational risk i.
Due to the large numbers of chemical contaminants, very few of them have been analyzed regarding their developmental or reproductive toxicity, considering the economical costs involved. Even if many organophosphorates have been banned internationally because of their high toxicity for human and animal health, many are still illegally used.
Occupational and enviromental influences on male fertility are at present of concern. It may be observed that many hazardous factors exist and different foci of attention are considered initially: It should be kept in mind that the contrast between data from experimental studies and observational data in human exemplifies an important distinction in toxicology, that between hazard and risk.
Experiments aimed purely at determining whether an agent has the potential to damage a biological system are concerned with hazard.
The concept of risk combines hazard and the biological context. Testicular cases are the more frequent and usually worse situations depending on the time and frequency of exposure and the testicular toxicant involved.
A retrospective study was conducted on the agroworkers in the banana plantations of Chinandega, Nicaragua, that used dibromochloropropane DBCP in their work ecotoxicklogia the decade of v s, to analyze their present seminal status by performing seminogram analysis, according to the WHO Laboratory Manual.
In the more severe cases, testicular biopsies were obtained and general absence of spermatogenic activity was found with a histological aspect like the Sertoli-only syndrome.
The study considered workers with different degrees of exposure, and in general, all sperm parameters were decreased significantly in terms of sperm count, motility, vitality and morphological normality, thus stressing the importance of adequate control of the exposed agroworkers Ortiz, Agropesticides are of ampie world-wide use. Among them, organophosphoric OP compounds, though restricted in many countries, are nevertheless employed in numerous places. In the OPMalathion S- 1l,2-bis- etoxi-carbonyl -ethyl -0,0-dimethyl-dithiophosphate was introduced as being less toxic than Parathion.
Both act by inhibiting acetylcholinesterase activity Hsu et al, In addition to the inhibition of cholinesterase activity resulting in accumulation of acetylcholine in the synapses and excessive stimulation of cholinergic receptors in the central and peripheric nervous system, that may even end by death of the subjectOP compounds also damage other tissues.
Along this line of research, we have published a biotest model in mice to analyze testicular toxicants damage elicited by contamination with OP agropesticides. Necrospermia and teratozoospermia mostly of the tail increased, with the presence of apoptotic cells and vacuolization of the seminiferous epithelium affecting mostly primary spermatocytes.
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There is also chromatin damage, with aneuploid spermatozoa. Paroxon is equally toxic and the commercial preparations of parathion and malathion are also very toxic.
In our animal studies, both in rodents ecotoxicplogia also in Eisenia foetida, cell and genetic damage is due to the overproduction of reactive oxygen species ROS.
Therefore, the protective role of a potent ROS scavenger such a Melatonin, was analyzed Sarabia et al, In press, a. Melatonin pretreatment prevented every alteration induced by diazinon, except a reduction of acetylcholinesterase plasmatic activity. Morph orne fcotoxicologia al analysis showed a decrease in seminiferous epithelium height.
An increase in testicular superoxide dismutase SOD activity terrextre detected day However, antioxidant pretreatment with melatonin prevents or diminishes this damage. In addition, diazinon damages mouse sperm DNA, which is also prevented by melatonin. Pretreatment with melatonin before diazinon acute administration improved all parameters studied on day 1 post injection of diazinon.
The organophosphorous pesticide diazinon is a dose-dependent testicular toxicant that alters the sperm DNA structure; melatonin is able to prevent this damage Sarabia et al.
Ecotoxicología y Daño Testicular. (Contaminación Química Ambiental): Revisión
Previous studies in our laboratory had shown similar results in mice intoxicated with the OP Malathion M which interferes with the normal spermatogenic eyele in mice, after a single dose and at intervals from 4 to ecotxoicologia days. Lead intoxication model as an example of heavy metal toxicity. Most of them represent environmental or labor risk. Lead toxicity is known to humanity since tereestre times and mentioned in documents leftby the Greeks, Romans and Arabs, and even the Egyptians.
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Ahmad et al, Lead is amply distributed in the environment and alters the physiology of many organic systems, including the male reproductive apparatus. In the literature, it has been reported that lead intoxication may cause oxidative stress Schafer etal. Therefore, at the same time the protective effect of a very efficient reactive oxygen species ROS scavenger molecule, such as melatonin MTNwas evaluated. Lead intoxication resulted in lower animal weight and MTN elicited higher weight.
The same was observed for testicular and cauda epididymal weight. Lead provokes disorganization of seminiferous epithelium, which is prevented by MTN. One of the mechanisms involved in lead toxicity is the loss of tissue homeostasis by an imbalance between pro-and antioxidative factors, which elicits oxidative damage of proteins, lipids and DNA El-Missiry, Melatonin has the ability to neutralize ROS and inhibit lipid peroxidation induced by a variety of agents Kim et al, Due to its low molecular weight and being lipophilic, melatonin is not only a good extracellular but also an excellent intracellular ROS scavenger Reiter et al, In addition, melatonin enhances metabolism, as observed in all parameters determined in mice, even compared to controls, a situation that agrees with a report by Reiter According to Adhikari et alhigh doses of Pb elicit apoptosis of germ cells Fig.
Depending on the dose, Pb can enter the tight junctions that form the inter-Sertoli so called blood-testis barrier, damaging the epithelium, with a decrease in its height due to germ cell loss, thus increasing the tubular lumen. All these events are caused by an excess of ROS, elicited by Pb toxicity. It is also possible that Pb flows in a retrograde manner via the tubular lumen, after entering the rete testis.
In the case of the male reproductive organs, it mightpresumably cross the blood-testis barrier and damage germ and Sertoli cells, thus altering normal spermatogenesis and sperm production.
This situation should be studied in depth. Melatonin is able to counteract these effects due to its antioxidative role. Boron as spermatogenic interfering chemical.
Boron is a chemical element used in a variety of industrial activities. In some places of the world, boron is a public health problem by contaminating drinking water, being the systems to reduce its concentration very costly. This is the case of the northern city of Arica, in Chile. WHO recommendation is of 0.
Height of the seminiferous epithelium are also greater for the boron group The same is seen for the tubular lumen the boron group is It would be interesting to establish in future works if the effect of boron in rodents follows stage-specific pattern in order to better understand the pathophysiology of the process. Boron alters the production of collagen by the cells of Ito, fibroblast and endothelial cells thus it elicits liver functional and architectural damage that may have endocrine consequences for normal testicular function.
A number of different terrestrial and aquatic species, bofh invertebrates and vertebrates, have been used for testing environmental contamination. Diazinon is a synfhetic pesticide widely used in agriculture, floriculture, and veterinary medicine. For this purpose, Eisenia foetida were reared in laboratory conditions. One group was exposed to increasing doses of the OP diazinon and examined at 1,7,10,15 and 30 days thereafter.
Gonadal morphology was examined testicular and seminal vesicles; E. It may be concluded that Eisenia foetida is an animal model, easy to use, inexpensive and representative of the changes that OP may elicit in other organisms.
It is also confirmed that this earthworm is an excellent biosentinel species. Lead induced death cell in testis of young rats. Study of the effeets of lead poisoning on the testes in albino rats. Influence of Phoxim on testicular and seminal vesicle organs, testosterone and cholinesterase level terreetre its tissue residues in male rats. P The effect of zinc supplementation on the effeets of lead on the rat testis. Ultraestructure of mouse teratozoospermia induced ecotoxicilogia Parathion.
Pesticide soil contamination mainly affeets earthworm male reproductive parameters. Lepidium meyenii Maca reduces spermatogenic damage induced by a single dose of malathion in mice. Melatonin as protective agent for the cytotoxic effects of Diazinon in the spermatogenesis in the earthworm Eiseniafoetida. Histopathological effects of boron on mouse liver.
Occupational and environmental Influences on Male Infertility. Male Reproductive Health and Dysfunction. Microbiological and biotechnological aspects of metabolismof ecotoxcologia and organophosphate. Critical Reviews in Biotechnology, Morphological alterations in mouse testis by a single dose of Malathion. Testicular alterations in rats due to gestational and early lactational administration of lead. Vida e Consciencia, Sao Paulo, Prophylactic effect of melatonin on lead-induced terrestrd of heme biosynthesis and deterioration of antioxidant systems in male rats.
Biochemical Molecular Toxicology,