k. karami

Plastics, as diverse polymeric materials, have become an integral part of modern life due to their unique properties, including high resistance to various chemicals, a high strength-to-weight ratio, ease of preparation, and low cost. Millions of tons of these materials are produced annually; however, only a small portion is recycled or reused. By leaving single-use plastics in the environment, these plastics are worn out and fragmented into smaller sizes due to various factors such as UV irradiation and oxidation and finally enter the aquatic and terrestrial ecosystems and based on their size are called Micro and Nanoplastics and may be uptaken by aquatic organisms such as fishes and also shrimps and accumulate in their tissues. They can also be absorbed by the roots of plants and enter the food chain of us humans. Although various in vitro and in vivo studies have been conducted to investigate the different effects of various nanoplastics, and various mechanisms such as oxidative stress and inflammation have been reported for their effects, but subchronic studies have been conducted to investigate the effects of polyethylene terephthalate nanoparticles. It is very important on the tissue of the heart in the body. As a result, it seems important to investigate their toxic effects in vital tissues such as heart tissue.

In this experimental study, polyethylene terephthalate Nanoplastics were prepared using aqueous solution and then characterized using Dynamic Light Scattering and Scanning Electronic Microscopy. Four weeks old 12 male wistar rats (Average weight=250 gr) were randomly divided into two groups. Animals in the treatment group received 200 ppm of polyethylene Terephthalate Nanoplastics by gavage daily for 90 days and Control group received only Phosphate Buffer Saline (pH=7.4). After this period, the rats were anesthetized and after collecting the serum, Lactate Dehydrogenase and Creatine Kinase activity levels were measured using commercial colorimetric kit. The level of Lipid Peroxidation was analyzed using Thiobarbituric acid reactive substance formation colorimetric assay, Total Antioxidant Capacity was assessed using Ferric reducing antioxidant power and Catalase Enzyme Activity were also measured in the heart tissue homogenate using specific kit, the results data were analyzed by one-way analysis of variance. Histopathological studies were also performed by hematoxylin and eosin staining using light microscopy.

The results demonstrated that long term exposure to polyethylene Terephthalate Nanoplastics caused a significant increase in the levels of Lactate Dehydrogenase and Creatine Kinase. Also, an increase in Lipid Peroxidation, and a decrement in Total Antioxidant Capacity, Catalase Activity were observed in the heart tissue of treatment group animals compared to the control group (P value < 0.05). In histological studies, intermuscular edema and degeneration of myofibrils were evident in the group that received Nanoplastics.

Long-term exposure to polyethylene terephthalate nanoplastics causes a change in the redox state of the heart tissue of male Wistar rats, these nanoparticles cause the cardiac antioxidant enzymatic and non-enzymatic defense mechanisms to be overwhelmed, such as reducing the total antioxidant capacity and catalase. which has finally led to irreversible damage to the cardiac tissue, which was confirmed by increasing serum levels of creatine kinase and lactate dehydrogenase enzymes and intramuscular edema and degeneration of myofibrils.

 Suboptimal levels of kid survival are the largest contributor to reproductive wastage in goat flocks. This results in substantial loss of production, producer, and industry income, and is increasingly being perceived as poor animal welfare. Improving kid survival is therefore a priority for the industry. Nutrient provision during gestation not only affects maternal status and reproductive performance but also affects prenatal and postnatal offspring growth and health. Although trace minerals (TM) are needed by the body in small amounts, they are essential nutrients for several metabolic functions such as growth, development, reproduction, and immunity. Furthermore, newborn animals are dependent upon their dams for the transfer of these nutrients via the placenta and the mammary gland. The antibodies obtained from colostrum are the only defense mechanism against environmental factors in neonatal ruminants. Inadequate nutrition of the dam, immune system suppression, and stress factors may lead to the production of low-quality colostrum. Management and feeding of high-quality colostrum can reduce kid mortality, strengthen immunity, and increase animal life span. Nutrition affects the development of the mammary gland, the onset of lactogenesis, and colostrum production, either by affecting some of the hormones that control these processes or by contributing nutrients that are in demand at this stage of pregnancy. Selenium plays an important role in preventing impaired function of the immune response. Copper deficiency has been shown to result in lowered bactericidal activities of blood leukocytes in ruminant animals. Zinc sufficiency has also been linked to proper immune functions. Therefore, this study aimed to investigate the effect of TM injection in late pregnancy on colostrum quality and plasma metabolites of Lori does and their kids.
Thirty Lori mature does with an average body weight of 40 kg and an age of 2-3 years were used. One month before the expected kidding, animals were divided into two groups (n=15 does/group) and randomly assigned to experimental treatments. Experimental treatments were no injection of trace minerals (Control; C) and injection of 1 mL of TM at four and two weeks before expected kidding. Blood samples were taken through the jugular vein. Each mL of TM solution contained 2.5 mg of Cu, 1.25 mg of Se, 5 mg of Mn, and 5 mg of Zn. All does were kept in similar nutritional and managerial conditions from mating to one month before kidding.
Results showed that plasma concentrations of glucose and total cholesterol (TC) tended to be higher and lower in the TM group at day 7 before kidding, respectively (P=0.06). Experimental treatments did not affect plasma triglyceride (TG), Ca, and Mg concentrations, and glutathione peroxidase (GPX) activity of does at day 7 before kidding (P>0.05). Whereas, TM injection before mating decreased plasma malondialdehyde (MDA) and increased total protein (TP), BRIX index (BI), superoxide dismutase (SOD), and total antioxidant activity at day 7 before kidding (P<0.05). Colostrum of does received TM had a higher fat, protein, and BI content and a lower lactose content than the colostrum of the C group (P<0.05). Plasma concentrations of glucose and MDA were lower in kids born from does received TM than those born from the C group (P<0.05). Experimental treatments did not affect plasma concentrations of TC, Ca, and Mg concentrations in kids (P>0.05). Kids born from does received TM had higher plasma concentrations of TG, TP, BI and SOD, GPX, and total antioxidant activity than those of the C group (P<0.05).
According to the results of the present experiment, injection of a TM solution containing Cu, Zn, Se, and Mn four and two weeks before birth increased the concentrations of TP and BI as well as the activity of antioxidant enzymes (SOD, GPX) and antioxidant capacity and reduced MDA concentration in Lori goat plasma. This improved the quality of colostrum produced by these does. Kids born from does receiving trace minerals had higher plasma concentrations of TP, BI, and activity of antioxidant enzymes (SOD, GPX), higher total antioxidant capacity, and lower concentrations of MDA compared to the C group. Therefore, this strategy may have beneficial effects on the health, viability, and performance of kids before weaning.