We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Combined effect and mechanism of microplastic with different particle sizes and levofloxacin on developing Rana nigromaculata: Insights from thyroid axis regulation and immune system
Summary
Researchers exposed developing frogs to a combination of microplastics of different sizes and the antibiotic levofloxacin at environmentally relevant levels. They found that the combination disrupted thyroid hormone regulation and immune system function more severely than either pollutant alone. The study suggests that microplastics and pharmaceutical contaminants together may pose compounding risks to amphibian development and health.
Microplastics (MPs) usually appear in the aquatic environment as complex pollutants with other environmental pollutants, such as levofloxacin (LVFX). After 45-day exposure to LVFX and MPs with different particle sizes at environmental levels, we measured the weight, snout-to-vent length (SVL), and development stages of Rana nigromaculata. Furthermore, we analyzed proteins and genes related to immune system and thyroid axis regulation, intestinal histological, and bioaccumulation of LVFX and MPs in the intestine and brain to further explore the toxic mechanism of co-exposure. We found MPs exacerbated the effect of LVFX on growth and development, and the order of inhibitory effects is as follows: LVFX-MP3>LVFX-MP1>LVFX-MP2. 0.1 and 1 μm MP could penetrate the blood-brain barrier, interact with LVFX in the brain, and affect growth and development by regulating thyroid axis. Besides, LVFX with MPs caused severer interference on thyroid axis compared with LVFX alone. However, 10 μm MP was prone to accumulating in the intestine, causing severe histopathological changes, interfering with the intestinal immune system and influencing growth and development through immune enzyme activity. Thus, we concluded that MPs could regulate the thyroid axis by interfering with the intestinal immune system.
Sign in to start a discussion.
More Papers Like This
The effect and mechanism of variable particle size microplastics and levofloxacin on the neurotoxicity of Rana nigromaculata based on the microorganism-intestine-brain axis
Researchers exposed frog tadpoles to microplastics of different sizes combined with an antibiotic and found that the combination caused nervous system damage through the gut-brain connection. The particle size of the microplastics influenced the severity of the neurotoxic effects, with certain sizes causing more behavioral changes than others. The study suggests that microplastics and antibiotics together in waterways may pose greater ecological risks than either pollutant alone.
Toxicity assessment of polyethylene microplastics in combination with a mix of emerging pollutants on Physalaemus cuvieri tadpoles
Researchers assessed the toxicity of polyethylene microplastics alone and in combination with a mixture of emerging pollutants on tadpoles of the frog Physalaemus cuvieri over 30 days. They found that combined exposure produced more severe effects on biomarkers related to oxidative stress and morphological development than individual exposures. The study highlights the need to consider how microplastics interact with other environmental contaminants when evaluating risks to amphibian populations.
Meta-analysis unravels the complex combined toxicity of microplastics and antibiotics in aquatic ecosystems
A meta-analysis of 730 datasets found that microplastics amplify antibiotic accumulation in aquatic organisms and worsen effects on growth, development, and immune function, but paradoxically appear to mitigate reproductive toxicity from antibiotics. The impact depends on biological response pathway, microplastic concentration, antibiotic properties, and exposure time, with an inverse relationship between antibiotic toxicity and both microplastic concentration and exposure duration.
Fate and effects of microplastics in combination with pharmaceuticals and endocrine disruptors in freshwaters: Insights from a microcosm experiment
Researchers conducted a microcosm experiment exposing moss and caddisflies to microplastics combined with pharmaceuticals and endocrine disruptors, finding that microplastics can alter the fate and biological effects of co-occurring chemical contaminants in freshwater ecosystems.
Combined effects of co-exposure to microcystin-LR and polystyrene microplastics on growth, brain pathology and thyroid hormone homeostasis in adult zebrafish
Researchers exposed zebrafish to microcystin-LR (a toxin from algal blooms) combined with polystyrene microplastics and found that the combination caused significantly worse brain damage and thyroid hormone disruption than either pollutant alone. The microplastics appeared to overwhelm the fish's ability to compensate for the algal toxin, leading to hormone imbalances that could affect growth and development. This is concerning because algal blooms and microplastics frequently occur together in polluted waterways, and their combined effects on the hormone system may be worse than expected.