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Simple Summary: In this study, we compared the effectiveness of two anesthetics, eugenol and tricaine methanesulfonate (MS-222), in consecutive administrations on zebrafish. We evaluated zebrafish behaviour after repeated anesthesia. Eugenol induced anesthesia more quickly than MS-222 but had longer recovery times. Additionally, swimming frequency decreased after eugenol anesthesia. The buffered version of MS-222 was more effective than the non-buffered one. We recommend using buffered MS-222 for studies requiring repeated, brief-duration anesthesia. The increasing use of the zebrafish (Danio rerio) in scientific experiments has made it necessary to implement anesthesia protocols guaranteeing minimum pain and suffering for these animals and ensuring the reliability of the results obtained from their research. Therefore, we aimed to compare the effectiveness of two anesthetics, eugenol and MS-222, in consecutive administrations and evaluate the zebrafish behaviour after repeated anesthesia. Thus, several zebrafish were anaesthetized with eugenol, MS-222, and buffered MS-222 three times repeatedly with a 24-h interval between each exposure. The induction and recovery periods were also timed. Their swimming frequency was determined after each exposure to assess their behaviour after the anesthesia. Anesthesia induction was quicker with eugenol compared to MS-222. However, eugenol presented longer recovery times, which were prolonged after each exposure. Also, the swimming frequency was reduced after each anesthesia with eugenol. The buffered version of MS-222 was more efficacious than the non-buffered one. Both versions of MS-222 did not affect the swimming frequency. Based on these findings, we recommend the utilization of MS-222 buffered rather than eugenol when repeated, brief-duration anesthesia is necessitated for a study. [ABSTRACT FROM AUTHOR]

Simple Summary: Endocrine disruptors are substances with a capacity to alter the endocrine system, one of the best known being bisphenol A. Bisphenol A is employed in the manufacture of a multitude of utensils used daily, and it is constantly being found polluting the environment and food. It is also an important aquatic pollutant, and its presence has been detected in coastal areas, rivers, and streams, among others. Due to its ubiquity, human and animal populations are frequently exposed to this compound. This work has compiled the effects on health of this substance, which are highly varied and are relevant in affecting reproduction and causing metabolic or immune system alterations, among others, as well as related to an increase in hormone-dependent pathologies, obesity, or type 2 diabetes. Monitoring the populations at risk and establishing a safe exposure level are proposed as being fundamental points in the control of exposure to this compound. Bisphenol A (BPA) is a chemical compound, considered as an "emerging pollutant", that appears ubiquitously, contaminating the environment and food. It is an endocrine disruptor, found in a multitude of consumer products, as it is a constituent of polycarbonate used in the manufacture of plastics and epoxy resins. Many studies have evaluated the effects of BPA, using a wide range of doses and animal models. In this work, we carried out a review of relevant research related to the effects of BPA on health, through studies performed at different doses, in different animal models, and in human monitoring studies. Numerous effects of BPA on health have been described; in different animal species, it has been reported that it interferes with fertility in both females and males and causes alterations in their offspring, as well as being associated with an increase in hormone-dependent pathologies. Similarly, exposure to BPA has been related to other diseases of great relevance in public health such as obesity, hypertension, diabetes, or neurodevelopmental disorders. Its ubiquity and nonmonotonic behavior, triggering effects at exposure levels considered "safe", make it especially relevant when both animal and human populations are constantly and inadvertently exposed to this compound. Its effects at low exposure levels make it essential to establish safe exposure levels, and research into the effects of BPA must continue and be focused from a "One Health" perspective to take into account all the factors that could intervene in the development of a disease in any exposed organism. [ABSTRACT FROM AUTHOR]

Simple Summary: Fish are an important source of proteins of a high biological value, of some vitamins and minerals, and of polyunsaturated omega-3 fatty acids. However, fish products can also allow harmful substances, like heavy metals, to enter the diet. Such substances are recognized as being the most serious contaminants for aquatic ecosystems at the present time. Their non-biodegradability allows them to accumulate in fish tissues, and then pass into human diets. Therefore, our study aimed to determine the concentrations of heavy metals (As, Cd, Cu, Hg, Ni, Pb, and Zn), and to evaluate the bioaccumulation patterns in the different types of musculature in two species of fish of commercial interest, Chelon auratus and Chelon saliens, from the south coast of the Caspian Sea. The results obtained emphasize the need to continue to monitor and evaluate the degree of pollution in the sampled area, both in fish and other species and also in the environment, as well as recommending prevention measures orientated towards limiting and/or reducing the excessive exposure of the human population to heavy metal contamination. Although fish is a food that supplies nutrients of a high biological value, they can also be a source of some harmful substances, such as heavy metals. In the same context, some human activities in the Caspian Sea have contaminated this ecosystem during the past few years. For those reasons, our objective consisted of determining the concentrations of heavy metals and evaluating their bioaccumulation patterns in the different types of musculature in two species of mullets of commercial interest, Chelon auratus and Chelon saliens, from the southern coast of this sea. For this purpose, 20 C. auratus and 29 C. saliens were caught off this coastline and the metal concentrations in 3 different muscle locations were analyzed: the ventral, dorsal and caudal muscles of each fish. The caudal muscle had higher concentrations of Cd, Cu, Pb, and Zn, whereas As, Hg and Ni accumulation seemed to be independent of the musculature type. Overall, the Cd, Hg, and Pb concentrations exceeded the maximum levels permitted in fish by the European Union. In addition, the relationships between pairs of metals were positive and elevated in all the cases, which could be a sign of heavy metal pollution in the region sampled. Therefore, it will be necessary to continue monitoring and evaluating the degree of pollution in the Caspian Sea. [ABSTRACT FROM AUTHOR]

Simple Summary: Living beings are constantly and inadvertently exposed to a series of environmental and food pollutants, triggering effects on health that are transmitted over generations. Bisphenol A is a compound produced in large amounts world-wide and used in the manufacture of plastic containers and other utensils for daily use. It is an environmental and food pollutant with a demonstrated capacity to produce effects on the health of organisms exposed to it. The objective of our study was to identify possible indirect biomarkers of effect by means of the analysis of the blood biochemistry, and of certain reproductive parameters of animals exposed to Bisphenol A in doses considered to be safe over different generations. Our results did not show any modifications in the reproduction parameters evaluated, such as the duration of the estrous cycle, the size of the litters, or the percentage of the young alive at weaning time. However, they showed that there were alterations in biochemical parameters like glucose, total proteins, and albumin, which could therefore, be regarded as indirect indicators of an early effect of alterations in health caused by this compound. Bisphenol A (BPA) is considered as being an emerging pollutant, to which both animal and human populations are continuously and inadvertently exposed. The identification of indirect biomarkers of effect could be a key factor in determining early adverse outcomes from exposure to low doses of BPA. Thus, this study on mice aims to evaluate and identify indirect biomarkers of effect through the analysis of their blood biochemistry, and of certain reproduction parameters after exposure to different BPA concentrations (0.5, 2, 4, 50, and 100 µg/kg BW/day) in drinking water over generations. Our results showed that there were no modifications in the reproductive parameters evaluated, like estrous cycle duration, litter size, or the percentage of the young alive at reaching the weaning stage, at the exposure levels evaluated. However, there were modifications in the biochemical parameters, e.g., alterations in the glucose levels, that increased significantly (p < 0.05) in the breeders at the higher exposure doses (50 and 100 µg/kg BW/day in F1; 50 µg/kg BW/day in F2 and 100 µg/kg BW/day in F3), that would suggest that the BPA could induce hyperglycemia and its complications in adult animals, probably due to some damage in the pancreas cells; albumin, that increased in the breeders exposed to the highest dose in F1 and F3, inferring possible hepatic alterations. Further, total proteins showed a diminution in their values in F1 and F2, except the group exposed to 100 µg/kg BW/day, whereas in F3 the values of this parameter increased with respect to the control group, this aspect likely being related to a possible hepatic and renal alteration. Based on these results, glucose, albumin, and total proteins could initially be considered as early indicators of indirect effect after prolonged exposure to low BPA doses over generations. [ABSTRACT FROM AUTHOR]